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1. Tuning the Coordination Environment of Ru(II) Complexes with a Tailored Acridine Ligand

Author: Ali Awada, Pierre-Henri Lanoë, Christian Philouze, Frédérique Loiseau, and Damien Jouvenot
Subjects: tridentate ligands, coordination geometry, ruthenium(II), acridine-based ligand, NMR spectroscopy, X-ray analyses, Organic chemistry, QD241-441
Abstract: A novel tridentate ligand featuring an acridine core and pyrazole rings, namely 2,7- di-tert-butyl-4,5-di(pyrazol-1-yl)acridine, L, was designed and used to create two ruthenium(II) complexes: [RuL2](PF6)2 and [Ru(tpy)L](PF6)2. Surprisingly, the ligand adopted different coordination modes in the complexes: facial coordination for the homoleptic complex and meridional coordination for the heteroleptic complex. The electronic absorption and electrochemical properties were evaluated. Although both complexes exhibited favorable electronic properties for luminescence, neither emitted light at room temperature nor at 77 K. This study highlights the complex interplay between ligand design, coordination mode, and luminescence in ruthenium(II) complexes.
Published: 2024
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2. Synthesis of an Electrodeficient Dipyridylbenzene-like Terdentate Ligand: Cyclometallating Ligand for Highly Emitting Iridium(III) and Platinum(II) Complexes

Author: Pierre-Henri Lanoë, Christian Philouze, and Frédérique Loiseau
Subjects: ligand synthesis, phosphorescence, platinum, iridium, blue emission, cyclometallating coordination, Organic chemistry, QD241-441
Abstract: Cyclometallated iridium(III) and platinum(II) complexes are intensely used in optoelectronics for their photophysical properties and ability to convert excitons from singlet to triplet state, thus improving the device efficiency. In this contribution, we report the multi-steps synthesis of an electrodeficient dipyridylbenzene-like terdentate ligand [N^C^N], namely 2′,6′-dimethyl-2,3′:5′,2″-terpyridine (6), with 18% overall yield. Compound 6 has been employed to synthesize two phosphorescent complexes of platinum(II) and iridium(III), namely compounds 7 and 8, respectively. Both complexes have been characterized by NMR and high resolution mass spectrometry, and demonstrate high luminescence quantum yields in a deaerated solution at room temperature, with 18% and 61% for 7 and 8, respectively. If the iridium(III) complex displays similar emission properties to [Ir(dpyx)(ppy)Cl] (dpyx = 3,5-dimethyl-2,6-dipyridylbenzene and ppy = 2- phenylpyridine), the platinum(II) derivative, with λem = 470 nm, is a rare example of a fluorine atom-free blue emitting [N^C^N]PtCl complex.
Published: 2023
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3. Anti-Proliferation and DNA Cleavage Activities of Copper(II) Complexes of N3O Tripodal Polyamine Ligands

Author: Doti Serre, Sule Erbek, Nathalie Berthet, Christian Philouze, Xavier Ronot, Véronique Martel-Frachet, and Fabrice Thomas
Subjects: copper, tripodal ligand, nuclease, DNA, phenol, Inorganic chemistry, QD146-197
Abstract: Four ligands based on the 2-tert-butyl-4-X-6-{Bis[(6-methoxy-pyridin-2-ylmethyl)-amino]-methyl}-phenol unit are synthesized: X = CHO (HLCHO), putrescine-pyrene (HLpyr), putrescine (HLamine), and 2-tert-butyl-4-putrescine-6-{Bis[(6-methoxy-pyridin-2-ylmethyl)-amino]-methyl}-phenol (H2Lbis). Complexes 1, 2, 3, and 4 are formed upon chelation to copper(II). The crystal structure of complex 1 shows a square pyramidal copper center with a very weakly bound methoxypridine moiety in the apical position. The pKa of the phenol moiety is determined spectrophotometrically at 2.82–4.39. All the complexes show a metal-centered reduction in their CV at Epc,red = −0.45 to −0.5 V vs. SCE. The copper complexes are efficient nucleases towards the ϕX174 DNA plasmid in the presence of ascorbate. The corresponding IC50 value reaches 7 μM for 2, with a nuclease activity that follows the trend: 2 > 3 > 1. Strand scission is promoted by the hydroxyl radical. The cytotoxicity is evaluated on bladder cancer cell lines sensitive (RT112) or resistant to cisplatin (RT112 CP). The IC50 of the most active complexes (2 and 4) is 1.2 and 1.0 μM, respectively, for the RT112 CP line, which is much lower than cisplatin (23.8 μM).
Published: 2023
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4. Symmetrical and Unsymmetrical Dicopper Complexes Based on Bis-Oxazoline Units: Synthesis, Spectroscopic Properties and Reactivity

Author: James A. Isaac, Gisèle Gellon, Florian Molton, Christian Philouze, Nicolas Le Poul, Catherine Belle, and Aurore Thibon-Pourret
Subjects: copper-bioinspired chemistry, mixed-valent CuIICuIII species, dioxygen activation, Inorganic chemistry, QD146-197
Abstract: Copper–oxygen adducts are known for being key active species for the oxidation of C–H bonds in copper enzymes and their synthetic models. In this work, the synthesis and spectroscopic characterizations of such intermediates using dinucleating ligands based on a 1,8 naphthyridine spacer with oxazolines or mixed pyridine-oxazoline coordination moieties as binding pockets for copper ions have been explored. On the one hand, the reaction of dicopper(I) complexes with O2 at low temperature led to the formation of a µ-η2:η2 Cu2:O2 peroxido species according to UV-Vis spectroscopy monitoring. The reaction of these species with 2,4-di-tert-butyl-phenolate resulted in the formation of the C–C coupling product, but no insertion of oxygen occurred. On the other hand, the synthesis of dinuclear Cu(II) bis-µ-hydroxido complexes based on pyridine–oxazoline and oxazoline ligands were carried out to further generate CuIICuIII oxygen species. For both complexes, a reversible monoelectronic oxidation was detected via cyclic voltammetry at E1/2 = 1.27 and 1.09 V vs. Fc+/Fc, respectively. Electron paramagnetic resonance spectroscopy (EPR) and UV-Vis spectroelectrochemical methods indicated the formation of a mixed-valent CuIICuIII species. Although no reactivity towards exogeneous substrates (toluene) could be observed, the CuIICuIII complexes were shown to be able to perform hydroxylation on the methyl group of the oxazoline moieties. The present study therefore indicates that the electrochemically generated CuIICuIII species described herein are capable of intramolecular aliphatic oxidation of C–H bonds.
Published: 2023
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5. Investigation of Chemical Composition and Biological Activities of Ajuga pyramidalis—Isolation of Iridoids and Phenylethanoid Glycosides

Author: Anthonin Gori, Benjamin Boucherle, Aurélien Rey, Maxime Rome, Caroline Barette, Emmanuelle Soleilhac, Christian Philouze, Marie-Odile Fauvarque, Nicola Fuzzati, and Marine Peuchmaur
Subjects: Ajuga pyramidalis, chemical composition, iridoids, phenylethanoid glycosides, antioxidant, epidermal renewal, Microbiology, QR1-502
Abstract: Despite several studies on the Ajuga L. genus, the chemical composition of Ajuga pyramidalis, an alpine endemic species, is still largely unknown. The purpose of this study was to therefore deeper describe it, particularly from the phytochemistry and bioactivity perspectives. In that respect, A. pyramidalis was investigated and 95% of the extracted mass of the plant was characterized by chromatography and mass spectrometry. Apart from the already determined chemical compounds, namely, harpagide and 8-O-acetylharpagide, two iridoids, and neoajugapyrin A, a neo-clerodane diterpene, and three polyphenols (echinacoside, verbascoside and teupoloside) were identified for the first time in A. pyramidalis. Incidentally, the first RX structure of a harpagoside derivative is also described in this paper. The extracts and isolated compounds were then evaluated for various biochemical or biological activities; notably a targeted action on the renewal of the epidermis was highlighted with potential applications in the cosmetic field for anti-aging.
Published: 2023
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6. Novel Synthesis of IMC-48 and Affinity Evaluation with Different i-Motif DNA Sequences

Author: Florian Berthiol, Joseph Boissieras, Hugues Bonnet, Marie Pierrot, Christian Philouze, Jean-François Poisson, Anton Granzhan, Jérôme Dejeu, and Eric Defrancq
Subjects: i-motif DNA, bio-layer interferometry, circular dichroism, affinity, IMC-48, DNA ligands, Organic chemistry, QD241-441
Abstract: During the last decade, the evidence for the biological relevance of i-motif DNA (i-DNA) has been accumulated. However, relatively few molecules were reported to interact with i-DNA, and a controversy concerning their binding mode, affinity, and selectivity persists in the literature. In this context, the cholestane derivative IMC-48 has been reported to modulate bcl-2 gene expression by stabilizing an i-motif structure in its promoter. In the present contribution, we report on a novel, more straightforward, synthesis of IMC-48 requiring fewer steps compared to the previous approach. Furthermore, the interaction of IMC-48 with four different i-motif DNA sequences was thoroughly investigated by bio-layer interferometry (BLI) and circular dichroism (CD) spectroscopy. Surprisingly, our results show that IMC-48 is a very weak ligand of i-DNA as no quantifiable interaction or significant stabilization of i-motif structures could be observed, stimulating a quest for an alternative mechanism of its biological activity.
Published: 2023
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7. Design and synthesis of a cyclitol-derived scaffold with axial pyridyl appendages and its encapsulation of the silver(I) cation

Author: Pierre-Marc Léo, Christophe Morin, and Christian Philouze
Subjects: cyclitol, glyco-scaffolds, hexadentate, scyllo-inositol, silver(I) complexation, Science, Organic chemistry, QD241-441
Abstract: Conversion of a myo-inositol derivative into a scyllo-inositol-derived scaffold with C3v symmetry bearing three axial pyridyl appendages is presented. This pre-organized hexadentate ligand allows complexation of silver(I). The crystal structure of the complex was established.
Published: 2010
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8. Synthesis of 4‐Phosphinylpyrrolidin‐3‐ones via [3+2] Cycloaddition of Nitrones with Phosphinylallenes

Author: Rayhane Hammami, Pascale Maldivi, Christian Philouze, Sébastien Carret, Benjamin Darses, Soufiane Touil, and Jean‐François Poisson
Subjects: General Chemistry
Published: 2023
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9. Cover Feature: Copper and Nickel Complexes of Oxamate−Phenol Containing Ligands: A Structural Dichotomy in Oxidized Species (Eur. J. Inorg. Chem. 15/2023)

Author: Guanqi Wang, Yohann Moreau, Florian Berthiol, Christian Philouze, Olivier Jarjayes, and Fabrice Thomas
Subjects: Inorganic Chemistry
Published: 2023
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10. On the Redox Properties of the Dimers of Thiazol-2-ylidenes That Are Relevant for Radical Catalysis

Author: Ludivine Delfau, Nadhrata Assani, Samantha Nichilo, Jacques Pecaut, Christian Philouze, Julie Broggi, David Martin, and Eder Tomás-Mendivil
Subjects: Cultural Studies, History, Literature and Literary Theory
Published: 2023
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11. Investigation of chemical composition and biological activities of $Ajuga\ pyramidalis$—isolation of iridoids and phenylethanoid glycosides

Author: Anthonin Gori, Benjamin Boucherle, Aurélien Rey, Maxime Rome, Caroline Barette, Emmanuelle Soleilhac, Christian Philouze, Marie-Odile Fauvarque, Nicola Fuzzati, Marine Peuchmaur, Département de pharmacochimie moléculaire (DPM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Chanel Parfums Beauté, Chanel, Jardin du Lautaret : découverte et sciences (Lautaret), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Genetics and Chemogenomics (GenChem), Laboratoire Biosciences et bioingénierie pour la santé (BGE), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Département de Chimie Moléculaire (DCM), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), and ANR-15-IDEX-0002,UGA,IDEX UGA(2015)
Subjects: antioxidant, iridoids, Endocrinology, Diabetes and Metabolism, Ajuga pyramidalis, chemical composition, [CHIM]Chemical Sciences, phenylethanoid glycosides, epidermal renewal, Molecular Biology, Biochemistry
Abstract: International audience; Despite several studies on the Ajuga L. genus, the chemical composition of $Ajuga\ pyramidalis$, an alpine endemic species, is still largely unknown. The purpose of this study was to therefore deeper describe it, particularly from the phytochemistry and bioactivity perspectives. In that respect, $A.\ pyramidalis$ was investigated and 95% of the extracted mass of the plant was characterized by chromatography and mass spectrometry. Apart from the already determined chemical compounds, namely, harpagide and 8-O-acetylharpagide, two iridoids, and neoajugapyrin A, a neo-clerodane diterpene, and three polyphenols (echinacoside, verbascoside and teupoloside) were identified for the first time in $A.\ pyramidalis$. Incidentally, the first RX structure of a harpagoside derivative is also described in this paper. The extracts and isolated compounds were then evaluated for various biochemical or biological activities; notably a targeted action on the renewal of the epidermis was highlighted with potential applications in the cosmetic field for anti-aging.
Published: 2023
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12. Synthesis of a Negative Photochrome with High Switching Quantum Yields and Capable of Singlet‐Oxygen Production and Storage

Author: Christian Philouze, Guy Royal, Martial Boggio-Pasqua, Elise Lognon, Frédérique Loiseau, Saioa Cobo, Zakaria Ziani, Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Laboratoire de Chimie et Physique Quantiques Laboratoire (LCPQ), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and ANR-18-CE29-0012,Photochromics,Architectures Moléculaires Multi-Photochromes Innovantes pour la Production de NO et 1O2(2018)
Subjects: 010405 organic chemistry, Singlet oxygen, Organic Chemistry, Quantum yield, General Chemistry, 010402 general chemistry, Photochemistry, Triphenylamine, 01 natural sciences, 7. Clean energy, Acceptor, Catalysis, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Photochromism, chemistry.chemical_compound, chemistry, Cyclic voltammetry, Methylpyridinium, Absorption (electromagnetic radiation)
Abstract: International audience; A dimethyldihydropyrene (DHP) photochromic unit has been functionalized by donor (triphenylamine group) and acceptor (methyl-pyridinium) substituents. This compound was characterized by NMR, absorption and emission spectroscopies as well as cyclic voltammetry and its properties were rationalized by theoretical calculations. The incorporation of both electron donor and withdrawing groups on the photochromic center allows i) an efficient photo-isomerization of the system when illuminated at low energy (quantum yield: Фc-o = 13.3% at λex.= 660 nm), ii) the reversible and quantitative formation of two endoperoxyde isomers when illuminated under aerobic conditions at room temperature and iii) the storage and production of singlet oxygen. The photo-isomerization mechanism was also investigated by spin-flip TD-DFT (SF-TD-DFT) calculations.
Published: 2021
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13. Functionalizing Carbon Nanotubes with Bis(2,9-dialkyl-1,10-phenanthroline)copper(II) Complexes for the Oxygen Reduction Reaction

Author: Deborah Brazzolotto, Yannig Nédellec, Christian Philouze, Michael Holzinger, Fabrice Thomas, and Alan Le Goff
Subjects: Inorganic Chemistry, Physical and Theoretical Chemistry
Abstract: A new ligand, namely, 2-(5-(pyren-1-yl)pentyl)-9-methyl-1,10-phenanthroline, as well as new bis(2,9-dialkyl-1,10-phenanthroline)copper(II) complexes were designed, which were immobilized on multiwalled carbon nanotube (MWCNT) electrodes. These complexes show a high tendency of autoreduction into their copper(I) form according to electrochemical and EPR experiments. These complexes exhibit strong interactions with MWCNT sidewalls either with or without anchor functions such as the pyrene moiety. The pyrene-modified derivative can be electropolymerized on glassy carbon and MWCNT electrodes to form a poly-[bis(2-(5-(pyren-1-yl)pentyl)-9-methyl-1,10-phenanthroline)copper(II)] metallopolymer film. Furthermore, these MWCNT-supported bis(2,9-dialkyl-1,10-phenanthroline)copper complexes demonstrate a low overpotential for a 4H
Published: 2022

14. Grafted dinuclear zinc complexes for selective recognition of phosphatidylserine: Application to the capture of extracellular membrane microvesicles

Author: Angéline Van der Heyden, Phoulinh Chanthavong, Eduardo Angles-Cano, Hugues Bonnet, Jérôme Dejeu, Audrey Cras, Christian Philouze, Guy Serratrice, Fatiha Zoubari El-Ghazouani, Florence Toti, Aurore Thibon-Pourret, and Catherine Belle
Subjects: Inorganic Chemistry, Biochemistry
Abstract: Microvesicles (MVs) are key markers in human body fluids that reflect cellular activation related to diseases as thrombosis. These MVs display phosphatidylserine at the outer leaflet of their plasma membrane as specific recognition moieties. The work reported in this manuscript focuses on the development of an original method where MVs are captured by bimetallic zinc complexes. A set of ligands have been synthetized based on a phenol spacer bearing in para position an amine group appended to a short or a longer alkyl chain (for grafting on surface) and bis(dipicolylamine) arms in ortho position (for zinc coordination). The corresponding dibridged zinc phenoxido and hydroxido complexes have been prepared in acetronitrile in presence of triethylamine and characterized by several spectroscopic techniques. The pH-driven interconversion studies for both complexes in H
Published: 2022

15. Copper Complexes of the Tetradentate N,N′ ‐Bis(2‐amino‐3,5‐di‐ tert ‐butylphenyl)‐2,2′‐diaminobiphenyl Ligand

Author: Nicolas Leconte, Christian Philouze, Fabrice Thomas, and Florian Berthiol
Subjects: Inorganic Chemistry, Chemistry, Ligand, Radical, chemistry.chemical_element, Electronic structure, Medicinal chemistry, Copper
Published: 2021
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16. Synthesis, characterization, structural analysis and electrocatalytic performance of zinc(II) porphyrinates

Author: Raoudha Soury, Mabrouka El Oudi, Ashanul Haque, Marwa Chaabene, Hani El-Moll, Khalaf M. Alenezi, Mahjoub Jabli, Safa Teka, Houcine Ghalla, Christian Philouze, and Amor Bchetnia
Subjects: Inorganic Chemistry, Organic Chemistry, Spectroscopy, Analytical Chemistry
Published: 2023
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17. Study of a phosphorescent cationic iridium(<scp>iii</scp>) complex displaying a blue-shift in crystals

Author: Frédérique Loiseau, Christian Philouze, Pierre-Henri Lanoë, Isabelle Gautier-Luneau, Emiliano Martínez-Vollbert, Yohann Moreau, Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Optique et Matériaux (NEEL - OPTIMA), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Chimie computationnelle, modélisation et rayons X (COMX), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Optique et Matériaux (OPTIMA)
Subjects: Photoluminescence, Materials science, 010405 organic chemistry, Ligand, Cationic polymerization, General Physics and Astronomy, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, 3. Good health, 0104 chemical sciences, Amorphous solid, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Crystallography, chemistry, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Hypsochromic shift, Iridium, Physical and Theoretical Chemistry, Phosphorescence, Two-dimensional nuclear magnetic resonance spectroscopy
Abstract: International audience; We report the synthesis and the characterization of a new cationic iridium(III) complex featuring two 1-(p-methoxyphenyl)-5-methoxybenzimidazole cyclometallating ligands and a dimethylbipyridine ancillary ligand. The complex has been fully characterized by 1D and 2D NMR (1H, 13C, 19F and 31P), elemental analysis and high-resolution mass spectrometry (HRMS). The photoluminescence studies performed in solution, on amorphous powder and on crystals revealed an unexpected behavior. Indeed, the emission spectra displayed in both solution (CH2Cl2) and amorphous powder samples are centered around 580 nm, whereas in crystals the emission displays a large hypsochromic shift of ~800 cm-1 (λem = 558 nm). X-ray diffraction experiments, photophysical studies and DFT calculation allow to rationalize the hypsochromic shift.
Published: 2021
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18. O2 Activation by Non-Heme Thiolate-Based Dinuclear Fe Complexes

Author: Marcello Gennari, Serhiy Demeshko, Lianke Wang, Christian Philouze, Franc Meyer, Sam P. de Visser, David Flot, Wesley R. Browne, Sandeep K. Padamati, Fabián G. Cantú Reinhard, Carole Duboc, Univ. Grenoble Alpes, CNRS, DCM, 38000 Grenoble, France, Institutes of Physical Science and Information Technology, Anhui University, Manchester Institute of Biotechnology and Department of Chemical Engineering and Analytical Science, Stratingh Institute for Chemistry and Chemical Engineering, University of Groningen [Groningen], European Synchrotron Radiation Facility (ESRF), Institute of Inorganic Chemistry, Georg-August-University [Göttingen], and Molecular Inorganic Chemistry
Subjects: MECHANISM, Coordination sphere, Dimer, Protonation, Crystal structure, 010402 general chemistry, 01 natural sciences, Redox, Inorganic Chemistry, chemistry.chemical_compound, [CHIM]Chemical Sciences, CRYSTAL-STRUCTURE, Reactivity (chemistry), Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS, DIMER, 010405 organic chemistry, Chemistry, Ligand, IRON, OXYGENATION, Comproportionation, REACTIVITY, 0104 chemical sciences, MODEL, Crystallography, CYSTEINE DIOXYGENASE, LIGAND, BOND
Abstract: Iron centers featuring thiolates in their metal coordination sphere (as ligands or substrates) are well-known to activate dioxygen. Both heme and non-heme centers that contain iron-thiolate bonds are found in nature. Investigating the ability of iron-thiolate model complexes to activate O2 is expected to improve the understanding of the key factors that direct reactivity to either iron or sulfur. We report here the structural and redox properties of a thiolate-based dinuclear Fe complex, [FeII 2(LS)2] (LS2- = 2,2′-(2,2′-bipyridine-6,6′-iyl)bis(1,1-diphenylethanethiolate)), and its reactivity with dioxygen, in comparison with its previously reported protonated counterpart, [FeII 2(LS)(LSH)]+. When reaction with O2 occurs in the absence of protons or in the presence of 1 equiv of proton (i.e., from [FeII 2(LS)(LSH)]+), unsupported μ-oxo or μ-hydroxo FeIII dinuclear complexes ([FeIII 2(LS)2O] and [FeIII 2(LS)2(OH)]+, respectively) are generated. [FeIII 2(LS)2O], reported previously but isolated here for the first time from O2 activation, is characterized by single crystal X-ray diffraction and Mössbauer, resonance Raman, and NMR spectroscopies. The addition of protons leads to the release of water and the generation of a mixture of two Fe-based "oxygen-free" species. Density functional theory calculations provide insight into the formation of the μ-oxo or μ-hydroxo FeIII dimers, suggesting that a dinuclear μ-peroxo FeIII intermediate is key to reactivity, and the structure of which changes as a function of protonation state. Compared to previously reported Mn-thiolate analogues, the evolution of the peroxo intermediates to the final products is different and involves a comproportionation vs a dismutation process for the Mn and Fe derivate, respectively.
Published: 2020
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19. Enantioselective approach for expanding the three‐dimensional space of tetrahydroquinoline to develop bet bromodomain inhibitors

Author: Marie‐Ange Lespinasse, Kaiyao Wei, Justine Perrin, Matthias Winkler, Sieme Hamaidia, Alexis Leroy, Zuzana Macek Jilkova, Christian Philouze, Patrice N. Marche, Carlo Petosa, Jérôme Govin, Anouk Emadali, Yung‐Sing Wong, Département de pharmacochimie moléculaire (DPM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institute for Advanced Biosciences / Institut pour l'Avancée des Biosciences (Grenoble) (IAB), Centre Hospitalier Universitaire [Grenoble] (CHU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Etablissement français du sang - Auvergne-Rhône-Alpes (EFS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Centre Hospitalier Universitaire [Grenoble] (CHU), Département de Chimie Moléculaire (DCM), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), ANR-18-CE18-0007,InhiBET,Développement de nouvelles molécules antifongiques ciblant les protéines BET(2018), wong, yung-sing, Grenoble, une chimie bio-motivée - - ARCANE2011 - ANR-11-LABX-0003 - LABX - VALID, CBH-EUR-GS - - CBH-EUR-GS2017 - ANR-17-EURE-0003 - EURE - VALID, and APPEL À PROJETS GÉNÉRIQUE 2018 - Développement de nouvelles molécules antifongiques ciblant les protéines BET - - InhiBET2018 - ANR-18-CE18-0007 - AAPG2018 - VALID
Subjects: [CHIM.ORGA]Chemical Sciences/Organic chemistry, [CHIM.THER] Chemical Sciences/Medicinal Chemistry, Organic Chemistry, Stereoisomerism, Antineoplastic Agents, General Chemistry, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, [CHIM.ORGA] Chemical Sciences/Organic chemistry, anti-inflammatory agent, Catalysis, tetrahydroquinoline, BET bromodomain inhibitor, Quinolines, za-ortho-quinone methide, organocatalysis
Abstract: International audience; The pharmaceutical industry has a pervasive need for chiral specific molecules with optimal affinity for their biological targets. However, the mass production of such compounds is currently limited by conventional chemical routes, that are costly and have an environmental impact. Here, we propose an easy access to obtain new tetrahydroquinolines, a motif found in many bioactive compounds, that is rapid and cost effective. Starting from simple raw materials, the procedure uses a proline-catalyzed Mannich reaction followed by the addition of BF3.OEt2, which generates a highly electrophilic aza-ortho-quinone methide intermediate capable of reacting with different nucleophiles to form the diversely functionalized tetrahydroquinoline. Moreover, this enantioselective one-pot process provides access for the first time to tetrahydroquinolines with a cis-2,3 and trans-3,4 configuration. As proof of concept, we demonstrate that a three-step reaction sequence, from simple and inexpensive starting compounds and catalysts, can generate a BD2-selective BET bromodomain inhibitor with anti-inflammatory effect.
Published: 2022
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20. Exploiting HOPNO-dicopper center interaction to development of inhibitors for human tyrosinase

Author: Elina Buitrago, Clarisse Faure, Marcello Carotti, Elisabetta Bergantino, Renaud Hardré, Marc Maresca, Christian Philouze, Nicolas Vanthuyne, Ahcène Boumendjel, Luigi Bubacco, Amaury du Moulinet d’Hardemare, Hélène Jamet, Marius Réglier, Catherine Belle, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Università degli Studi di Padova = University of Padua (Unipd), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de pharmacochimie moléculaire (DPM), Aix Marseille Université (AMU), (ANR-11-LABX-0003-01), Labex Arcane, (ANR-15-IDEX-02), Cosmethics 2.0, and (ANR-17-EURE-003), CBH-EUR-GS
Subjects: Pharmacology, Melanin, Organic Chemistry, Drug Discovery, [CHIM]Chemical Sciences, Inhibitor development, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, General Medicine, Human tyrosinase, Dicopper center
Abstract: International audience; In human, Tyrosinase enzyme (TyH) is involved in the key steps of protective pigments biosynthesis (in skin, eyes and hair). The use of molecules targeting its binuclear copper active site represents a relevant strategy to regulate TyH activities. In this work, we targeted 2-Hydroxypyridine-N-oxide analogs (HOPNO, an established chelating group for the tyrosinase dicopper active site) with the aim to combine effects induced by combination with a reference inhibitor (kojic acid) or natural substrate (tyrosine). The HOPNO-MeOH (3) and the racemic amino acid HOPNO-AA compounds (11) were tested on purified tyrosinases from different sources (fungal, bacterial and human) for comparison purposes. Both 2 compounds have more potent inhibitory activities than the parent HOPNO moiety and display strictly competitive inhibition constant, in particular with human tyrosinase. Furthermore, 11 appears to be the most active on the B16-F1 mammal melanoma cells. The investigations were completed by stereospecificity analysis. Racemic mixture of the fully protected amino acid 10 was separated by chiral HPLC into the corresponding enantiomers. Assignment of the absolute configuration of the deprotected compounds was completed, based on X-ray crystallography. The inhibition activities on melanin production were tested on lysates and whole human melanoma MNT-1 cells. Results showed significant enhancement of the inhibitory effects for the (S) enantiomer compared to the (R) enantiomer. Computational studies led to an explanation of this difference of activity based for both enantiomers on the respective position of the amino acid group versus the HOPNO plane.
Published: 2023
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21. Synthesis of Redox-Active Photochromic Phenanthrene Derivatives

Author: Elarbi Chatir, Martial Boggio‐Pasqua, Frederique Loiseau, Christian Philouze, Guy Royal, Saioa Cobo, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Photochimie théorique et computationnelle (LCPQ) (PTC), Laboratoire de Chimie et Physique Quantiques Laboratoire (LCPQ), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)
Subjects: [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, General Chemistry, Catalysis
Abstract: International audience; A phenanthrene unit has been functionalized by several methylthiophene units in order to bring it a photochromic behavior. These compounds were characterized by NMR, absorption and emission spectroscopies, theoretical calculations as well as cyclic voltammetry. The association of a phenanthrene group with a photochromic center could open the door to a new generation of organic field-effect transistors.
Published: 2021
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22. High-valence CuIICuIII species in action: demonstration of aliphatic C–H bond activation at room temperature

Author: Christian Philouze, Amélie Durand, Aurore Thibon-Pourret, Nicolas Le Poul, Catherine Belle, James A. Isaac, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Chimie Moléculaire de Grenoble (ICMG), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Université de Brest (UBO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut Brestois Santé Agro Matière (IBSAM), and Université de Brest (UBO)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
Subjects: aliphatic C–H bond activation, Reactive intermediate, chemistry.chemical_element, CuII, Oxidative phosphorylation, 010402 general chemistry, Photochemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Materials Chemistry, [CHIM]Chemical Sciences, CuIICuIII, C h bond, Valence (chemistry), 010405 organic chemistry, Chemistry, Metals and Alloys, [CHIM.CATA]Chemical Sciences/Catalysis, General Chemistry, Copper, Toluene, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, C-H bond activation, copper, Ceramics and Composites, CuIII, Stoichiometry
Abstract: International audience; The electrochemically generated CuIICuIII mixed-valence species promotes activation of strong aliphatic C–H bonds (i.e. toluene) at room temperature. The mechanistic pathway turns from stoichiometric to catalytic upon addition of base, hence demonstrating that such high-valence dicopper species can be key reactive intermediates in copper-based oxidative processes.
Published: 2019
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23. Synthesis and Characterization of Bis‐1,2,3‐Triazole Ligand and its Corresponding Copper Complex for the Development of Electrochemical Affinity Biosensors

Author: Thierry Noguer, Carole Calas-Blanchard, Fabrice Thomas, Nicolas Inguimbert, Wassim Rammal, Amani Ben Jrad, Hussein Kanso, Christian Philouze, Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Biocapteurs-Analyses-Environnement (BAE), and Université de Perpignan Via Domitia (UPVD)
Subjects: Aptamer, Triazole, chemistry.chemical_element, Biosensing Techniques, Crystallography, X-Ray, Ligands, 010402 general chemistry, Electrochemistry, 01 natural sciences, Catalysis, chemistry.chemical_compound, Deprotonation, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Carbodiimide, 010405 organic chemistry, Chemistry, Ligand, Organic Chemistry, Electron Spin Resonance Spectroscopy, General Chemistry, Triazoles, Combinatorial chemistry, Copper, 0104 chemical sciences, 3. Good health, Biosensor
Abstract: International audience; The bis-triazole ligand and its corresponding copper complexes were synthesized and characterized for the first time and proposed as new labels for the development of electrochemical aptasensors. The bis-triazole ligand was prepared from methyl 1,6-heptadiyne-4-carboxylate and 2-(azidomethyl)phenol using classical CuAAC in presence of different copper salts. The X-ray structure of bis-triazole showed a symmetry center (C1). UV-Vis and X-band EPR spectra showed that the coordination capacity of the bis-triazole ligand was improved in the presence of triethylamine due to deprotonation of the triazole and phenolate moieties. After complexation with copper, the obtained complex was successfully attached to an anti-estradiol aptamer through thiol-maleimide coupling, and the resulting labelled aptamer was immobilized on a carbon screen-printed electrode by carbodiimide coupling. The electrochemical response of the resulting sensor was shown to decrease in the presence of estradiol, demonstrating that the developed complexes can be applied for the development of aptasensors.
Published: 2021
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24. Asymmetric Intramolecular Buchner Reaction: From High Stereoselectivity to Coexistence of Norcaradiene, Cycloheptatriene, and an Intermediate Form in the Solid State

Author: Christian Philouze, Pascale Maldivi, Jean-François Poisson, Philippe Dauban, Benjamin Darses, Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Chimie des Substances Naturelles (ICSN), Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Valence (chemistry), Bicyclic molecule, 010405 organic chemistry, Chemistry, [CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry, Absolute configuration, Cycloheptatriene, Crystal structure, 010402 general chemistry, 01 natural sciences, Biochemistry, 0104 chemical sciences, Stereocenter, Crystallography, chemistry.chemical_compound, Intramolecular force, [CHIM.CRIS]Chemical Sciences/Cristallography, Stereoselectivity, Physical and Theoretical Chemistry
Abstract: International audience; Bicyclic compounds bearing a quaternary stereogenic center have been obtained using asymmetric intramolecular Buchner reaction with excellent yields and level of enantioselectivity. X-ray crystallography determination of the absolute configuration of one product has led to the serendipitous observation of an unusual behavior within the crystal structure, with equilibrating norcaradiene and cycloheptatriene valence isomers at the solid state, as well as an even more unexpected intermediate form. DFT calculations were performed to support these observations.
Published: 2021
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25. Two novel pyrazine Zn(II)-porphyrins complexes: Synthesis, photophysical properties, structure study, DFT-Calculation and assessment of an azo dye removal from aqueous solution

Author: Raoudha Soury, Marwa Chaabene, Ashanul Haque, Mahjoub Jabli, Khalaf M. Alenezi, Salman Latif, Fahad Abdulaziz, Amor Bchetnia, and Christian Philouze
Subjects: Inorganic Chemistry, Materials Chemistry, Ceramics and Composites, Physical and Theoretical Chemistry, Condensed Matter Physics, Electronic, Optical and Magnetic Materials
Published: 2022
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26. Ditopic Chelators of Dicopper Centers for Enhanced Tyrosinases Inhibition

Author: Christian Philouze, Elina Buitrago, Lylia Challali, Marc Maresca, Elisabetta Bergantino, Ahcène Boumendjel, Marius Réglier, Marcello Carotti, Luigi Bubacco, Catherine Belle, Clarisse Faure, Hélène Jamet, Renaud Hardré, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Università degli Studi di Padova = University of Padua (Unipd), Département de pharmacochimie moléculaire (DPM), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-11-LABX-0003,ARCANE,Grenoble, une chimie bio-motivée(2011), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Universita degli Studi di Padova
Subjects: bioinorganic chemistry, copper active sites, ditopic inhibitors, docking, tyrosinases, Chelating Agents, Enzyme Inhibitors, Humans, Structure-Activity Relationship, Agaricales, Monophenol Monooxygenase, Stereochemistry, Tyrosinase, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, Melanin, chemistry.chemical_compound, Moiety, Chelation, [CHIM.COOR]Chemical Sciences/Coordination chemistry, chemistry.chemical_classification, biology, 010405 organic chemistry, Organic Chemistry, Active site, General Chemistry, 0104 chemical sciences, Enzyme, chemistry, Docking (molecular), biology.protein, Kojic acid
Abstract: International audience; Tyrosinase enzymes (Tys) are involved in the key steps of melanin (protective pigments) biosynthesis and molecules targeting the binuclear copper active site on tyrosinases represent a relevant strategy to regulate enzyme activities. In this work, we studied the possible synergic effect generated by combination of known inhibitors. For this, derivatives containing kojic acid (KA) and 2-Hydroxypyridine-N-oxide (HOPNO) combined with a thiosemicarbazone (TSC) moiety were synthetized. Their inhibition activities were evaluated on purified tyrosinases from different sources (mushroom, bacterial and human) as well as on melanin production by lysates from human melanoma MNT-1 cell line. Results showed significant enhancement of the inhibitory effects compared to the parent compounds, in particular for HOPNO-TSC. In order to elucidate the interaction mode with the dicopper(II) active site, we investigated the binding studies towards a tyrosinase bio-inspired model of the dicopper(II) center. The structure of the isolated adduct between one ditopic inhibitor (KA-TSC) and the model complex reveals that the binding to a dicopper center can occur with both chelating sites. Computational studies on model complexes and docking studies on enzymes led to the identification of KA and HOPNO moieties as interacting groups with the dicopper active site.
Published: 2020
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27. Distorted copper( ii ) radicals with sterically hindered salens: electronic structure and aerobic oxidation of alcohols

Author: Christian Philouze, Tim Storr, Florian Berthiol, R Kunert, Olivier Jarjayes, Fabrice Thomas, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire - Synthèse Et Réactivité en Chimie Organique (DCM - SeRCO), Department of Chemistry, and Simon Fraser University (SFU.ca)
Subjects: Steric effects, Coordination sphere, 010405 organic chemistry, Chemistry, Radical, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Redox, 0104 chemical sciences, law.invention, Inorganic Chemistry, Metal, Metal salen complexes, law, visual_art, Alcohol oxidation, visual_art.visual_art_medium, [CHIM]Chemical Sciences, Electron paramagnetic resonance, ComputingMilieux_MISCELLANEOUS
Abstract: The sterically hindered salen ligands featuring biphenyl and tetramethyl putrescine linkers were synthesized and chelated to copper. The resulting complexes CuLbp,tBu, CuLbp,OMe, CuLpu,tBu and CuLpu,OMe were structurally characterized, showing a significanty tetrahedrally distorted metal center. The complexes show two reversible oxidation waves in the range 0.2 to 0.8 V vs. Fc+/Fc. A further reduction wave is detected in the range -1.4 to -1.7 V vs. Fc+/Fc. It is reversible for CuLbp,tBu and CuLbp,OMe and assigned to the CuII/CuI redox couple. One-electron oxidation of CuLbp,OMe, CuLpu,tBu and CuLpu,OMe was performed chemically and electrochemically. It is accompanied by a quenching of the EPR resonances. Phenoxyl radical formation was established by X-Ray diffraction on the cations [CuLbp,OMe]+ and [CuLpu,OMe]+, whereby the coordination sphere is elongated upon oxidation with quinoidal distributions of bond distances. The cations exhibit a NIR band of moderate intensity in their optical spectrum, supporting their classification as class II mixed-valent radical species according to the Robin Day classification. The proposed electronic structures are supported by DFT calculations. The cations [CuLbp,OMe]+, [CuLpu,tBu]+ and [CuLpu,OMe]+ were active towards aerobic oxidation of the unactivated alcohol 2-phenylethanol, with TON numbers up to 58 within 3 h.
Published: 2020
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28. Chromones bearing amino acid residues: Easily accessible and potent inhibitors of the breast cancer resistance protein ABCG2

Author: Aline Thomas, Emile Roussel, Pierre Falson, Alexis Moreno, Basile Pérès, Olivier Renaudet, Ahcène Boumendjel, Nicolas Altounian, Christian Philouze, Institut de biologie et chimie des protéines [Lyon] (IBCP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de pharmacochimie moléculaire (DPM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université Grenoble Alpes (UGA), and CALIXAR
Subjects: Abcg2, Cell Survival, Antineoplastic Agents, ATP-binding cassette transporter, [CHIM.THER]Chemical Sciences/Medicinal Chemistry, 01 natural sciences, Mice, Structure-Activity Relationship, 03 medical and health sciences, chemistry.chemical_compound, Valine, Drug Discovery, ATP Binding Cassette Transporter, Subfamily G, Member 2, Animals, Humans, [CHIM]Chemical Sciences, Amino Acids, ComputingMilieux_MISCELLANEOUS, Cells, Cultured, Cell Proliferation, 030304 developmental biology, Pharmacology, chemistry.chemical_classification, 0303 health sciences, Dose-Response Relationship, Drug, Molecular Structure, biology, 010405 organic chemistry, Chemistry, Organic Chemistry, Transporter, General Medicine, Neoplasm Proteins, 3. Good health, 0104 chemical sciences, Amino acid, Molecular Docking Simulation, Multiple drug resistance, Biochemistry, Chromones, Docking (molecular), Chromone, biology.protein, Drug Screening Assays, Antitumor
Abstract: The Breast Cancer Resistance Protein (BCRP/ABCG2) belongs to the G class of ABC (ATP-Binding Cassette) proteins, which is known as one of the main transporters involved in the multidrug resistance (MDR) phenotype that confer resistance to anticancer drugs. The aim of this study was to design, synthesize and develop new potent and selective inhibitors of BCRP that can be used to abolish MDR and potentialize clinically used anticancer agents. In previous reports, we showed the importance of chromone scaffold and hydrophobicity for the inhibition of ABC transporters. In the present study we report the design and development of chromones linked to one or two amino acids residues that are either hydrophobic or found in the structure of FTC, one of most potent (but highly toxic) inhibitors of BCRP. Herewith, we report the synthesis and evaluation of 13 compounds. The studied molecules were found to be not toxic and showed strong inhibition activity as well as high selectivity toward BCRP. The highest activity was obtained with the chromone bearing a valine residue (9c) which showed an inhibition activity against BCRP of 50 nM. The rationalization of the inhibition potential of the most active derivatives was performed through docking studies. Taken together, the ease of synthesis and the biological profile of these compounds render them as promising candidates for further development in the field of anticancer therapy.
Published: 2020
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29. Complexes of the Bis(di-tert-butyl-aniline)amine Pincer Ligand: The Case of Copper

Author: Christian Philouze, Florian Molton, Solène Gentil, Nicolas Leconte, Fabrice Thomas, Alan Le Goff, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Solar fuels, hydrogen and catalysis (SolHyCat), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Département de Chimie Moléculaire - Biosystèmes Electrochimiques et Analytiques (DCM - BEA ), Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Iminosemiquinones, Electronic structure, Coordination sphere, Spin states, 010405 organic chemistry, Ligand, chemistry.chemical_element, Disproportionation, Radicals, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Copper, 0104 chemical sciences, law.invention, Inorganic Chemistry, Crystallography, Deprotonation, chemistry, law, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Electron paramagnetic resonance, Pincer ligand, Phenylenediamine
Abstract: International audience; TheN,N-bis(2-amino-3,5-di-tert-butylphenyl)amine pincer ligand was coordinated to copper. Depending on the copper source, a mononuclear complex1(+)or a trimer2could be isolated and were structurally characterized. Complex1(+)consists of two deprotonated iminobenzoquinone ligands coordinated to a Cu(I) center. Complex2is trinuclear with a (3:3) (M:L) stoichiometry, featuring a three-fold repetition of a unit made of a Cu(II) center coordinated to a tridentate ligand radical-dianion. In2, the metal ions are bridged by an anilido nitrogen. The coordination sphere of each copper is completed to four by a neighboring iminosemiquinone moiety. Complex1(+)belongs to an electron-transfer series. The paramagnetic complexes1and1(2+)were generated and characterized by EPR and Vis-NIR spectroscopy. Complex1exhibits an isotropic resonance at g = 2.00, which is reminiscent of Cu(I) iminosemiquinone species. The dication1(2+)exhibits a metal-based ground spin state and hence is described as a Cu(II) iminobenzoquinone complex. Both1and1(+)show a NIR band (954, 980 nm) of high intensity (> 20 mm(-1) cm(-1)) assigned to ligand-based charge transfer transitions. Two-electron reduction of1produces2via ligand release and disproportionation. Conversely, oxidation of2affords1(+). Finally, carbon-nanotube-supported complex2is active towards electrocatalytic reduction of H2O2.
Published: 2020
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30. Structural and spectroscopic investigations of nine-coordinate redox active lanthanide complexes with a pincer O,N,O ligand

Author: R. Barré, Christian Philouze, M Bryden, Daniel Imbert, Fabrice Thomas, D. Mouchel Dit Leguerrier, Olivier Jarjayes, Jennifer K. Molloy, Dominique Luneau, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Catalyse Bioinorganique et Environnement (BioCE ), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Multimatériaux et Interfaces (LMI), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), and ANR-17-CE07-0034,Co-lantha,Complexes de lanthanides comme sondes redox radicalaires(2017)
Subjects: Lanthanide, 010405 organic chemistry, Ligand, Chemistry, Diradical, Crystal structure, Zero field splitting, 010402 general chemistry, 01 natural sciences, 3. Good health, 0104 chemical sciences, law.invention, Inorganic Chemistry, Crystallography, Absorption band, law, [CHIM.CRIS]Chemical Sciences/Cristallography, Molecule, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Electron paramagnetic resonance
Abstract: International audience; The lanthanide complexesEuL(3),GdL3,YbL(3)andLuL(3)of theN,N '-bis(2-hydroxy-di-3,5-tert-butylphenyl)amine were prepared. The X-Ray crystal structures ofGdL(3)andLuL(3)demonstrated a nine-coordinate sphere with three ligand molecules under their anionic diamagnetic form (Cat-N-BQ)(-). The complexes showed three oxidation events (Eox11/2 = 0.15-0.16 V,E-1/2(2)= 0.51-55 V, andE(1/2)(3)= 0.75-0.78 Vvs.Fc(+)/Fc)viacyclic voltammetry, corresponding to the successive oxidation of the aminophenolate moeities to iminosemiquinone species. The complexesGdL(3)andYbL(3)were characterized by EPR spectroscopy, allowing for the determination of the zero field splitting (ZFS) parameters in the first case. The monocations(LnL(3))(+)and monoanions(LnL(3))(-)were electrochemically generated (Ln = Eu, Gd, Yb, Lu), as well as the dicationsYbL(3)(2+)andLuL(3)(2+). The spins are antiferromagnetically exchange coupled in the diradical speciesLuL(3)(2+)(|D| = 260 MHz,E= 0). All the complexes (incl. neutral) possess a strong absorption band in the NIR region (730-840 nm,epsilon> 19 mM(-1)cm(-1)) corresponding to ligand-based transitions.
Published: 2020
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31. Effect of Distortions on the Geometric and Electronic Structures of One-Electron Oxidized Vanadium(IV), Copper(II), and Cobalt(II)/(III) Salen Complexes

Author: Hussein Kanso, Christian Philouze, Tim Storr, Amélie Kochem, Ryan M. Clarke, Himanshu Arora, Olivier Jarjayes, and Fabrice Thomas
Subjects: Coordination sphere, Denticity, 010405 organic chemistry, Ligand, Dimer, Crystal structure, 010402 general chemistry, 01 natural sciences, Square pyramidal molecular geometry, 0104 chemical sciences, law.invention, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, chemistry, Octahedron, law, Physical and Theoretical Chemistry, Electron paramagnetic resonance
Abstract: The ligands N,N'-bis(3-tert-butyl-5-methoxysalicylidene)-1,2-ethanediamine and N,N'-bis(3-tert-butyl-5-methoxysalicylidene)-1,3-propanediamine were chelated to V(IV)═O (1, 2), Cu(II) (3, 4), Co(II) (5), and Co(III) (6). The X-ray crystal structures of 1-6 were solved. The vanadium center in 1-2 resides in square pyramidal geometry, with an axially bound oxo ligand, whereas the metal ion displays a tetrahedrally distorted square planar geometry in 3-5. The extent of distortion is correlated to the length of the diamine spacer: The longer the linker, the larger the tetrahedral distortions. Complex 6 is octahedral with a bidentate acetate molecule that completes the coordination sphere. All the complexes were characterized by UV-vis and EPR spectroscopies, as well as DFT calculations and electrochemistry. Complexes 1-6 exhibit a reversible one-electron oxidation wave in the range -0.11-0.26 V vs Fc+/Fc. The cations 1+ and 2+ were structurally characterized, showing an octahedral V(V) ion with one oxo and one water molecule coordinated in axial positions. Their vis-NIR spectra are dominated by a band at 727 and 815 nm, respectively, which is assigned to a phenolate-to-vanadium(V) charge transfer (CT) transition. The crystal structures of 3+ and 4+ are congruent with Cu(II)-radical species, wherein the metal center remains four-coordinated. Both feature a Class II (Robin-Day classification scale) IVCT transition at around 1200 nm (e > 1 mM cm-1), indicative of partial localization of the radical. The structure of 5+ displays a square pyramidal cobalt ion, where the fifth (axial) coordination is occupied by a water molecule. It displays a NIR feature at 1244 nm and is described as intermediate between high spin Co(III) and Co(II) radical. In the presence of acetate the dimer [(5)2(μ-OAc)]+ forms, which was structurally characterized and shows a blue shift and lowering in intensity of the NIR absorption band in comparison to 5+. Complex 6+ is a genuine Co(III) radical complex, wherein the phenoxyl moiety is localized on one side of the molecule.
Published: 2020

32. O

Author: Lianke, Wang, Marcello, Gennari, Fabián G, Cantú Reinhard, Sandeep K, Padamati, Christian, Philouze, David, Flot, Serhiy, Demeshko, Wesley R, Browne, Franc, Meyer, Sam P, de Visser, and Carole, Duboc
Abstract: Iron centers featuring thiolates in their metal coordination sphere (as ligands or substrates) are well-known to activate dioxygen. Both heme and non-heme centers that contain iron-thiolate bonds are found in nature. Investigating the ability of iron-thiolate model complexes to activate O
Published: 2020

33. Improved Visible Light Absorption of Potent Iridium(III) Photo-oxidants for Excited-State Electron Transfer Chemistry

Author: Christian Philouze, Eric J. Piechota, Sara A. M. Wehlin, Michaël Abraham, Gerald J. Meyer, Robin Bevernaegie, Ludovic Troian-Gautier, Benjamin Elias, and UCL - SST/IMCN/MOST - Molecular Chemistry, Materials and Catalysis
Subjects: Light, Biochimie, Phenazine, chemistry.chemical_element, Electrons, 010402 general chemistry, Photochemistry, Iridium, 01 natural sciences, Biochemistry, Catalysis, chemistry.chemical_compound, Electron transfer, Reaction rate constant, Colloid and Surface Chemistry, Chimie des colloïdes, Coordination Complexes, Pyridine, Chimie, Absorption (electromagnetic radiation), Photosensitizing Agents, Chimie des surfaces et des interfaces, General Chemistry, 0104 chemical sciences, chemistry, Excited state, Catalyses hétérogène et homogène, Oxidation-Reduction, Visible spectrum
Abstract: Three iridium photosensitizers, [Ir(dCF3ppy)2(N-N)]+, where N-N is 1,4,5,8-tetraazaphenanthrene (TAP), pyrazino[2,3-a]phenazine (pzph), or benzo[a]pyrazino[2,3-h]phenazine (bpph) and dCF3ppy is 2-(3,5-bis(trifluoromethyl-phenyl)pyridine), were found to be remarkably strong photo-oxidants with enhanced light absorption in the visible region. In particular, judicious ligand design provided access to Ir-bpph, with a molar absorption coefficient, ϵ = 9800 M-1 cm-1, at 450 nm and an excited-state reduction potential, E(Ir+*/0) = 1.76 V vs NHE. These complexes were successful in performing light-driven charge separation and energy storage, where all complexes photo-oxidized seven different electron donors with rate constants (0.089-3.06) × 1010 M-1 s-1. A Marcus analysis provided a total reorganization energy of 0.7 ± 0.1 eV for excited-state electron transfer., SCOPUS: ar.j, info:eu-repo/semantics/published
Published: 2020

34. Role of the Metal Ion in Bio-Inspired Hydrogenase Models: Investigation of a Homodinuclear FeFe Complex vs Its Heterodinuclear NiFe Analogue

Author: Lianke Wang, Christian Philouze, Alexandre Barrozo, Carole Duboc, Franc Meyer, Jennifer Fize, Maylis Orio, Marcello Gennari, Serhiy Demeshko, Vincent Artero, Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Solar fuels, hydrogen and catalysis (SolHyCat), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Institut für Anorganische Chemie, Georg-August-University = Georg-August-Universität Göttingen, ANR-16-CE92-0012,NiFemim,Catalyseurs bio-inspirés de l'hydrogénase à [NiFe] pour la production d'hydrogène.(2016), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Georg-August-University [Göttingen]
Subjects: Coordination sphere, mechanism, 010402 general chemistry, 01 natural sciences, Catalysis, Metal, Cyclopentadienyl complex, Moiety, electrocatalysis, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Isostructural, H2 production, biology, 010405 organic chemistry, Chemistry, Ligand, Active site, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, metal thiolate, 0104 chemical sciences, Crystallography, Catalytic cycle, visual_art, FeFe hydrogenase, visual_art.visual_art_medium, biology.protein
Abstract: International audience; In nature, dihydrogen is catalytically produced or split by the [FeFe] and [NiFe] hydrogenases. Despite common structural features in their dinuclear active site, i.e., a thiolate-rich coordination sphere and CO/CN– ligation, the synergetic way, in which the two metal sites act during catalysis, is specific for each enzyme. With the aim of understanding the role of the nature of the metal (Fe vs Ni), we report on a homodinuclear FeFe complex, a parent of a previously reported NiFe complex, to compare their electrocatalytic activity for H2 production. The di-iron complex [(CO)LN2S2FeIIFeII(CO)Cp]+ (with LN2S2 = 2,2′-(2,2′-bipyridine-6,6′-diyl)bis(1,1-diphenylethanethiolate and Cp = cyclopentadienyl) has been synthesized and fully characterized. In the solid state, it contains two CO ligands: one bound to the {FeCp} moiety in a semibridging manner and one terminally bound to the {FeLN2S2} moiety. This dinuclear iron complex is thus not isostructural to [LN2S2NiIIFeII(CO)Cp]+, which contains a single CO ligand terminally bound to the Fe site. However, at low concentrations in MeCN solutions, the CO ligand coordinated to the {FeLN2S2} moiety is removed and the CO ligand bound to the {FeCp} moiety becomes fully bridging between the two Fe sites. Under such conditions, the di-iron complex displays similar catalytic performances to the parent NiFe complex (a comparable overpotential, η = 730 and 690 mV, and TON = 15 and 16, respectively). Cyclic voltammetry data give direct experimental evidence for an E[ECEC] mechanism, which was also previously proposed for the NiFe complex. However, the structure of the one-electron reduced species, the entry point of the catalytic cycle, slightly differs for the two systems: in [LN2S2NiI(CO)FeIICp], this is valence localized species on the site Ni and the CO ligand bridges the two metal ions, while in [(CO)LN2S2FeFeCp], this is a type II–III mixed-valence species with the CO terminally bound to the {FeLN2S2} unit.
Published: 2020
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35. Synthesis of unsymmetrical 1,8-naphthyridine-based ligands for the assembly of tri-and tetra-nuclear copper(II) complexes

Author: Christian Philouze, Aurore Thibon-Pourret, Felix Bacher, David Flot, James A. Isaac, Catherine Belle, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and European Synchrotron Radiation Facility (ESRF)
Subjects: 010405 organic chemistry, Ligand, Imine, chemistry.chemical_element, General Chemistry, 010402 general chemistry, 01 natural sciences, Copper, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Amide, Polymer chemistry, Materials Chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Binding site, Acetonitrile, Trifluoromethanesulfonate, Triethylamine
Abstract: International audience; A synthetic route to unsymmetrical 1,8-naphthyridine spacer based ligands is presented. Reaction of a 7-ethyldipyridyl-1,8-naphthyridine-2-carboxaldehyde intermediate with 2-aminophenol or 4,6-di-tert-butyl 2-aminophenol led to the formation of ligands, HL1 and HL2, respectively. Both combined two distinct binding sites: a dipyridyl and an iminophenol site linked through a 1,8-naphthyridine spacer. Treatment of HL1 with copper(II) triflate in the presence of triethylamine/H2O in acetonitrile afforded a tetranuclear complex (1tox·2CH3CN). X-ray analysis revealed that the structure is constituted by the association of two identical dinuclear units in which the imine is oxidized to an amide group during the complexation. The coordination capabilities of the corresponding free amide ligands H2L1ox and H2L2ox, prepared by an independent route, were explored using copper(II) triflate in the presence of triethylamine/H2O. With the amide ligand, H2L1ox, a similar tetranuclear copper complex (1tox·2DMF) compared to the one isolated after complexation with the imine ligand HL1 was formed, as evidenced by X-ray diffraction studies. In contrast, H2L2ox, where the amido phenol arm exhibits two additional tert-butyl groups, has allowed the formation of a trinuclear copper complex (2triox·H2O).
Published: 2020
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36. Tuning Reactivity of Bioinspired [NiFe]-Hydrogenase Models by Ligand Design and Modeling the CO Inhibition Process

Author: Franc Meyer, Vincent Artero, Carole Duboc, Christian Philouze, Lianke Wang, Hao Tang, Maylis Orio, Michael B. Hall, Marcello Gennari, Deborah Brazzolotto, Serhiy Demeshko, Nicolas Queyriaux, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA., University of Texas, Institut für Anorganische Chemie (XXX), Georg-August-University = Georg-August-Universität Göttingen, Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE92-0012,NiFemim,Catalyseurs bio-inspirés de l'hydrogénase à [NiFe] pour la production d'hydrogène.(2016), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie Moléculaire de Grenoble (ICMG), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut für Anorganische Chemie, Georg-August-University [Göttingen], Institut für Anorganische Chemie, Georg-August Universität Göttingen, Georg-August-Universität Göttingen, Institut de Chimie Moléculaire de Grenoble (ICMG)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institute of Inorganic Chemistry, Biozentrum, University of Basel (Unibas), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Steric effects, Hydrogenase, 010402 general chemistry, Electrocatalyst, 01 natural sciences, Redox, Catalysis, hydrogenases, bioinspired chemistry, nickel, iron, Cyclopentadienyl complex, H-2 production, [CHIM]Chemical Sciences, electrocatalysis, Reactivity (chemistry), ComputingMilieux_MISCELLANEOUS, 010405 organic chemistry, Ligand, Chemistry, small-molecule activation, [CHIM.CATA]Chemical Sciences/Catalysis, General Chemistry, 0104 chemical sciences, Crystallography, Density functional theory
Abstract: International audience; Despite the report of several structural and functional models of the [NiFe]-hydrogenases, it is still unclear how the succession of electron and proton transfers during H-2 production catalysis are controlled in terms of both sequence (order of the chemical or redox steps) and sites (metal and/or ligand). To address this issue, the structure of the previously described bioinspired [NiFe]-hydrogenase complex [(LNiFII)-Ni-N2S2-F-II Cp(CO)](+) ((LNiFeCp)-Fe-II-Cp-II, with L-N2S2 = 2,2'-(2,2'-bipyridine-6,6'-diy1)bis(1,1'-diphenylethanethiolate) and Cp = cyclopentadienyl) has been fine-tuned by modifying exclusively the Fe site. In [(LNiFeCp)-Ni-N2S2-Fe-II-Cp-II* (CO)](+) ((LNiFeCp)-Fe-II-Cp-II*, with Cp* = pentamethylcyclopentadienyl), the Cp- ligand has been replaced by Cp*- to change both the redox and structural properties of the overall complex as a consequence of the steric hindrance of Cp*-. The (LNiFeCp)-Fe-II-Cp-II* complex acts as an efficient electrocatalyst to produce H-2. Density functional theory (DFT) calculations support a CEEC cycle, following an initial reduction. The initial protonation leads to the cleavage of one thiolate-iron bond and the next reduction to the generation of a bridging Fe-based hydride moiety. Interestingly, the second protonation step generates a species containing a terminal Ni-based thiol and a bridging hydride. In the presence of CO, the electrocatalytic activity of (LNiFeCp)-Fe-II-Cp-II* for H-2 production is markedly inhibited (about 90% of loss), while only a partial inhibition (about 30% of loss) is observed in the case of (LNIFeCp)-I-II-Cp-II. DFT calculations rationalized this effect by predicting that interactions of the one- and two-electron-reduced species for (LNiFeCp)-Fe-II-Cp-II* with CO are thermodynamically more favorable in comparison to those for (LNiFeCp)-Fe-II-Cp-II.
Published: 2018
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37. Copper(II) complexes of N3O ligands as models for galactose oxidase: Effect of variation of steric bulk of coordinated phenoxyl moiety on the radical stability and spectroscopy

Author: Nicolas Leconte, Christian Philouze, Fabrice Thomas, Cédric Colomban, Florian Molton, Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire d'Automatique, de Mécanique et d'Informatique industrielles et Humaines - UMR 8201 (LAMIH), Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Centre National de la Recherche Scientifique (CNRS)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Steric effects, Coordination sphere, 010405 organic chemistry, Stereochemistry, chemistry.chemical_element, Protonation, 010402 general chemistry, Resonance (chemistry), 01 natural sciences, Copper, 0104 chemical sciences, Inorganic Chemistry, Trigonal bipyramidal molecular geometry, chemistry.chemical_compound, Crystallography, chemistry, Pyridine, Materials Chemistry, [CHIM]Chemical Sciences, Moiety, Physical and Theoretical Chemistry, ComputingMilieux_MISCELLANEOUS
Abstract: Three N3O tripodal ligands (two pyridines, one phenol) HLMes, HLTRIP and HLNap were synthesized. The phenol ortho substituent is a mesityl, 2,4,6-tri-isopropylphenyl or 2-naphthyl group, respectively. The dinuclear copper(II)-phenolate complexes [μOH-Cu2II(LMes)(HLMes)]2+ and [Cu2II(LNap)2]2+ were isolated as single crystals. In [μOH-Cu2II(LMes)(HLMes)]2+ the two copper centers are bridged by a hydroxo unit. In [Cu2II(LNap)2]2+ two phenolate groups bridge the copper atoms. In the absence of base the mononuclear copper(II)-phenol complexes are formed. The complexes [CuII(HLMes)(CH3CN)]2+ and [CuII(HLNap)(CH3CN)]2+ were structurally characterized, showing a distorted octahedral copper ion. The phenol remains protonated and occupies one axial position, while a counter ion is weakly bound on the opposite position and an acetonitrile molecule completes the coordination sphere. In the presence of pyridine mononuclear copper(II)-phenolate complexes of general formula [CuII(LNap)(Py)]+, [CuII(LMes)(Py)]+ and [CuII(LTRIP)(Py)]+ are obtained. The copper(II)-phenol complexes exhibit a reversible reduction wave in the range −0.27 to −0.29 V vs. Fc+/Fc in their CV curve, which corresponds to the CuII/CuI redox couple, as well as an irreversible oxidation wave. In the presence of pyridine a reversible oxidation wave is observed at 0.09–0.13 V. It is assigned to the phenoxyl/phenolate redox couple. The one-electron oxidized copper(II)-phenoxyl complexes are mononuclear triplet species, as judged by the ΔMS = 2 resonance in their EPR spectra. The |D| value is estimated at 1700 MHz (axial ZFS). All these radical species exhibit an intense band at 427 nm, which combines the features of both phenoxyl π–π∗ and CT transitions. The stability of the radicals follows the order [CuII(LNap)(Py)]2+ > [CuII(LMes)(Py)]2+ > [CuII(LTRIP)(Py)]2+. By DFT calculations we show that all the phenoxyl radical species adopt a common trigonal bipyramidal geometry, wherein the phenoxyl moiety coordinates in the trigonal plane. They possess a triplet ground spin state due to the orthogonality between the two SOMOs, which mainly correspond to dz2 and phenoxyl π orbitals.
Published: 2018
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38. Short synthesis, X-ray and conformational analysis of a cyclic peracetylated <scp>l</scp>-sorbose-derived nitrone, a useful intermediate towards N–O-containing <scp>d</scp>-gluco-iminosugars

Author: Salia Tangara, Christian Philouze, Jean-Bernard Behr, Sandrine Py, Alice Kanazawa, Martine Fayolle, and Jean-François Poisson
Subjects: chemistry.chemical_classification, 010405 organic chemistry, Stereochemistry, Diastereomer, X-ray, Regioselectivity, General Chemistry, 010402 general chemistry, Sorbose, 01 natural sciences, Catalysis, 0104 chemical sciences, Nitrone, chemistry.chemical_compound, Enzyme, chemistry, Materials Chemistry, Glycoside hydrolase
Abstract: The synthesis of the peracetylated ketonitrone 4 is described in four steps from L-sorbose. This cyclic nitrone is crystalline and proved to preferentially adopt a 4H3 conformation with all acetate groups in pseudo-axial orientation. Nitrone 4 undergoes regioselective cycloadditions with alkynes, affording tetra-O-acetyl-isoxazolines with good yields and stereoselectivities (4 : 1 to 9 : 1 diastereomeric ratio). Nitrone 4 and the obtained isoxazolines were smoothly deacetylated to produce the polyhydroxylated nitrone 5 and novel iminosugars containing an isoxazoline motif. Evaluation of their glycosidase inhibitory activity demonstrated their rather weak, but selective affinity for a variety of enzymes.
Published: 2018
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39. A highly active diradical cobalt(<scp>iii</scp>) catalyst for the cycloisomerization of alkynoic acids

Author: Christian Philouze, Nicolas Leconte, Amaury du Moulinet d'Hardemare, and Fabrice Thomas
Subjects: Coordination sphere, 010405 organic chemistry, Diradical, Metals and Alloys, chemistry.chemical_element, Regioselectivity, General Chemistry, engineering.material, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Cycloisomerization, chemistry, Polymer chemistry, Materials Chemistry, Ceramics and Composites, engineering, Noble metal, Reactivity (chemistry), Chemoselectivity, Cobalt
Abstract: The first cobalt-catalysed cycloisomerisation of alkynoic acids is reported, thanks to the design of a well-defined diradical cobalt(iii) catalyst, in the absence of any additives. The high efficiency, regioselectivity and chemoselectivity are comparable to those of noble metal-based systems. The unique reactivity might be attributed to second coordination sphere effects.
Published: 2018
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40. Tetranuclear and dinuclear phenoxido bridged copper complexes based on unsymmetrical thiosemicarbazone ligands

Author: A.-T. Mansour, Marius Réglier, Rolf David, Christian Philouze, Hélène Jamet, Catherine Belle, Franc Meyer, Aurore Thibon-Pourret, S. Caldarelli, Ariane Jalila Simaan, Amélie Kochem, Serhiy Demeshko, James A. Isaac, Mehdi Yemloul, Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Georg-August-University = Georg-August-Universität Göttingen, Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de recherches sur la catalyse (IRC), Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), and Georg-August-University [Göttingen]
Subjects: 010405 organic chemistry, Chemistry, Ligand, Substituent, chemistry.chemical_element, Nuclear magnetic resonance spectroscopy, 010402 general chemistry, Electrochemistry, 01 natural sciences, Copper, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, Magic angle spinning, [CHIM]Chemical Sciences, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Acetonitrile, Semicarbazone, ComputingMilieux_MISCELLANEOUS
Abstract: We report on the synthesis of new dinucleating phenol-based "end-off" compartmental ligands HLMeH and HLMe2 bearing two different binding sites, one bis(2-methylpyridyl)aminomethyl (BPA) and one thiosemicarbazone (TSC) site, and their corresponding copper(ii) complexes 1t and 2d. With the ligand HLMeH, a tetranuclear entity (1t) has been isolated in the solid state, whereas with HLMe2, which differs from HLMeH by a methyl substituent on the N-terminal amino group of the TSC arm, a dinuclear form (2d) is obtained. X-ray crystallography analysis shows that the nuclearity di vs. tetra is modulated by interactions between copper atoms and hydroxido bridges along with the sulphur atoms of TSC arms. From a magnetic point of view, 1t can be considered as an association of two dinuclear forms leading for both complexes to overall antiferromagnetic coupling. Analysis in acetonitrile solution of structure-property relationships has been carried out by comparing their UV/Vis, electrochemistry, ESI-MS, and NMR (variable temperature and DOSY = diffusion ordered spectroscopy) properties with trends from computational calculations (DFT). HRMAS-DOSY (High Resolution Magic Angle Spinning) NMR spectroscopy has been performed to evaluate the presence of different species in solution at room temperature.
Published: 2018
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41. Cover Feature: Synthesis of a Negative Photochrome with High Switching Quantum Yields and Capable of Singlet‐Oxygen Production and Storage (Chem. Eur. J. 67/2021)

Author: Zakaria Ziani, Frédérique Loiseau, Elise Lognon, Martial Boggio‐Pasqua, Christian Philouze, Saioa Cobo, and Guy Royal
Subjects: Organic Chemistry, General Chemistry, Catalysis
Published: 2021
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42. Synthesis and characterization of axially modified Zn(II) porphyrin complexes for methylene blue dye oxidative degradation

Author: Christian Philouze, Khalaf M. Alenezi, Mahjoub Jabli, Ahmed Al Otaibi, Hani El Moll, Ashanul Haque, and Raoudha Soury
Subjects: 010405 organic chemistry, Ligand, Organic Chemistry, Quantum yield, DABCO, 010402 general chemistry, Electrochemistry, 01 natural sciences, Porphyrin, Redox, 0104 chemical sciences, Analytical Chemistry, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, chemistry, Spectroscopy, Methylene blue, Octane
Abstract: In the present work, we report synthesis, structural elucidation and photophysical properties of new pentacoordinated Zn(II) porphyrinates (1-2). Complexes with formula [Zn(TEBOP)(DABCO)](DABCO) (1) [TEBOP = meso-tetrakis(ethyl-4(4-butyryl)oxyphenyl) porphyrinato), DABCO = 1,4-diazabicyclo [2.2.2] octane], and (2) [Zn(TEBOP)(pyz)] [pyz = pyrazine] have been studied to explore the effects of axial ligand on the structural and photophysical properties of [Zn(TEBOP)]. Both the solution and solid-state characterization unambiguously confirmed the pentacordinated nature of the complexes 1 and 2. The X-ray molecular structures showed that these complexes exhibited high ruffling deformation. We showed here that some of the optical properties (absorption features and quantum yield) could be modulated by varying the axial ligand whereas emission wavelength (λem) and lifetime (τf) values were found to remain unchanged. Electrochemical studies suggested that the characteristic reduction and oxidation potentials of the porphyrin ring varied with the axial ligand. Finally, [Zn(TEBOP)] and complexes 1 and 2 were checked for the oxidative degradation of methylene blue (C0 = 30 mg/L, T = 22°C, pH = 6, H2O2 = 4 mL/L). The degradation yields followed the order: [Zn(TEBOP)] + H2O2 (47%) > 2 (38.5.9%) > 1 (26.9%).
Published: 2021
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43. A High‐Valent Non‐Heme μ‐Oxo Manganese(IV) Dimer Generated from a Thiolate‐Bound Manganese(II) Complex and Dioxygen

Author: Abayomi S. Faponle, Christian Philouze, Deborah Brazzolotto, Marcello Gennari, Sam P. de Visser, Julian Smith‐Jones, Kallol Ray, Fabián G. Cantú Reinhard, Carole Duboc, Marius Retegan, Lucia Amidani, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), University of Manchester [Manchester], School of Chemical Engineering and Analytical Sciences [Manchester], European Synchrotron Radiation Facility (ESRF), Institut für Chemie der Humboldt-Universität zu Berlin, Humboldt-Universität zu Berlin, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Humboldt University Of Berlin, Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), Department of Chemistry, Département de Chimie Moléculaire [2016-2019] (DCM [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique [2016-2019] (DCM - CIRE [2016-2019]), and Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: 010405 organic chemistry, Dimer, chemistry.chemical_element, Homogeneous catalysis, Protonation, General Chemistry, Manganese, General Medicine, Photochemistry, Mass spectrometry, 010402 general chemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Crystallography, chemistry.chemical_compound, chemistry, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Yield (chemistry), [CHIM]Chemical Sciences, Reactivity (chemistry), Non heme, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; This study deals with the unprecedented reactivity of dinuclear non-heme MnII -thiolate complexes with O2 , which dependent on the protonation state of the initial MnII dimer selectively generates either a di-μ-oxo or μ-oxo-μ-hydroxo MnIV complex. Both dimers have been characterized by different techniques including single-crystal X-ray diffraction and mass spectrometry. Oxygenation reactions carried out with labeled 18 O2 unambiguously show that the oxygen atoms present in the MnIV dimers originate from O2 . Based on experimental observations and DFT calculations, evidence is provided that these MnIV species comproportionate with a MnII precursor to yield μ-oxo and/or μ-hydroxo MnIII dimers. Our work highlights the delicate balance of reaction conditions to control the synthesis of non-heme high-valent μ-oxo and μ-hydroxo Mn species from MnII precursors and O2 .
Published: 2017
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44. High-valence Cu

Author: James A, Isaac, Aurore, Thibon-Pourret, Amélie, Durand, Christian, Philouze, Nicolas, Le Poul, and Catherine, Belle
Abstract: The electrochemically generated CuIICuIII mixed-valence species promotes activation of strong aliphatic C-H bonds (i.e. toluene) at room temperature. The mechanistic pathway turns from stoichiometric to catalytic upon addition of base, hence demonstrating that such high-valence dicopper species can be key reactive intermediates in copper-based oxidative processes.
Published: 2019

45. Stable M(II)-Radicals and Nickel(III) Complexes of a Bis(phenol) N-Heterocyclic Carbene Chelated to Group 10 Metal Ions

Author: Olivier Jarjayes, Fabrice Thomas, Christian Philouze, and Romain Kunert
Subjects: Coordination sphere, 010405 organic chemistry, Ligand, Radical, Metal ions in aqueous solution, chemistry.chemical_element, Crystal structure, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Inorganic Chemistry, Metal, chemistry.chemical_compound, Nickel, chemistry, visual_art, visual_art.visual_art_medium, Physical and Theoretical Chemistry, Carbene
Abstract: The tetradentate ligand based on (1-imidazolium-3,5-ditert-butylphenol) units was prepared and chelated to group 10 metal ions (Ni(II), Pd(II), and Pt(II)), affording complexes 1, 2, and 3, respectively. The X-ray crystal structures of 1–3 show a square planar metal ion coordinated to two N-heterocyclic carbenes and two phenolate moieties. The cyclic voltammetry curves of complexes 1–3 show two reversible oxidation waves in the range 0.11–0.21 V (E1/21) and 0.55–0.65 V (E1/22) vs Fc+/Fc, which are assigned to the successive oxidations of the phenolate moieties. One-electron oxidation affords mononuclear (S = 1/2) systems. Complex 1+·SbF6– was remarkably stable, and its structure was characterized. The coordination sphere is slightly dissymmetric, while the typical patterns of phenoxyl radicals were observed within the ligand framework. Complex 1+ exhibits a rhombic signal at g = 2.087, 2.016, and 1.992, confirming its predominant phenoxyl radical character. The g-values are slightly smaller for 2+ (2.021,...
Published: 2019

46. A Non-Heme Diiron Complex for (Electro)catalytic Reduction of Dioxygen:Tuning the Selectivity through Electron Delivery

Author: Carole Duboc, Vincent Artero, Christian Philouze, Lianke Wang, Franc Meyer, Javier Gutiérrez, Adina Morozan, Fabián G. Cantú Reinhard, Sam P. de Visser, Marcello Gennari, Serhiy Demeshko, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Manchester Institute of Biotechnology, University of Manchester [Manchester], School of Chemical Engineering and Analytical Sciences [Manchester], Solar fuels, hydrogen and catalysis (SolHyCat ), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut für Anorganische Chemie (XXX), Georg-August-University [Göttingen], Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Georg-August-University = Georg-August-Universität Göttingen, ANR-16-CE92-0012,NiFemim,Catalyseurs bio-inspirés de l'hydrogénase à [NiFe] pour la production d'hydrogène.(2016), and ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017)
Subjects: Coordination sphere, Reducing agent, Chemistry, Selective catalytic reduction, General Chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 010402 general chemistry, Electrocatalyst, ResearchInstitutes_Networks_Beacons/manchester_institute_of_biotechnology, 01 natural sciences, Biochemistry, Combinatorial chemistry, Catalysis, 0104 chemical sciences, Metal, chemistry.chemical_compound, Colloid and Surface Chemistry, visual_art, Manchester Institute of Biotechnology, visual_art.visual_art_medium, Selectivity, Acetonitrile
Abstract: International audience; In the Oxygen Reduction Reaction (ORR) domain, the investigation of new homogeneous catalysts is a crucial step towards the full comprehension of the key structural and/or electronic factors that control catalytic efficiency and selectivity. Herein, we report a unique non-heme diiron complex that can act as a homogeneous ORR catalyst in acetonitrile solution. This iron(II)-thiolate dinuclear complex, [FeII2(LS)(LSH)] ([Fe2SH]+) (LS2- = 2,2'-(2,2'-bipyridine-6,6'-diyl)bis(1,1-diphenylethanethiolate)) contains a thiol group in the metal coordination sphere. [Fe2SH]+ is an efficient ORR catalyst both in the presence of a one-electron reducing agent as well as under electrochemically assisted conditions. However, its selectivity is dependent on the electron delivery pathway, in particular, the process is selective for H2O2 production under chemical conditions (up to ~95%), whereas H2O is the main product during electrocatalysis (less than ~10% H2O2). Based on computational work alongside the experimental data, a mechanistic proposal is discussed that rationalizes the selective and tunable reduction of dioxygen.
Published: 2019
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47. Neutral heteroleptic cyclometallated Platinum(II) complexes featuring 2-phenylbenzimidazole ligand as bright emitters in solid state and in solution

Author: Frédérique Loiseau, Laura Wilson, Damien Jouvenot, Christian Philouze, Cyrille Monnereau, Angélica Moreno-Betancourt, Pierre-Henri Lanoë, Hélène Jamet, Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Chimie - UMR5182 (LC), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC), Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE ), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Ligand, Chemistry, Process Chemistry and Technology, General Chemical Engineering, Solid-state, Substituent, chemistry.chemical_element, Quantum yield, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Ring (chemistry), Photochemistry, 01 natural sciences, Redox, 0104 chemical sciences, 3. Good health, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry.chemical_compound, Absorption (chemistry), 0210 nano-technology, Platinum, ComputingMilieux_MISCELLANEOUS
Abstract: A series of 8 neutral cyclometallated platinum(II) complexes featuring 2-phenylbenzimidazole chromophoric ligand and acetylacetonate as ancillary ligand has been synthesized and characterized. The introduction of a variety of substituent on the phenyl ring allows to finely tune the emission wavelength. The emission data reveal high quantum yield in deaerated solution and in bulk solid state (micro-crystalline powder), with values up to an impressive 51%. The emission for all of the complexes is attributed to a mixed 3LC-MLCT state. Both absorption and emission data have been correlated successfully with the redox potentials and the Hammett parameters.
Published: 2019
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48. Synthesis of novel bis(cyano) meso-tetraphenylporphyrinato-chromium(III), [K(2 2 2)] [CrIII(TPP)(CN)2] 2.(C7H6O2) (III), and (Chloro) meso-tetraphenylporphyrinato-chromium(III), [CrIII(TPP)Cl] (II): Spectroscopic, physico-chemical, and decolorization properties

Author: Christian Philouze, Mahjoub Jabli, Raoudha Soury, Habib Nasri, Azhar kechich, and Khalaf M. Alenezi
Subjects: Calmagite, chemistry.chemical_classification, Ligand, chemistry.chemical_element, 02 engineering and technology, Crystal structure, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Porphyrin, Medicinal chemistry, 0104 chemical sciences, Catalysis, Coordination complex, Inorganic Chemistry, chemistry.chemical_compound, Chromium, chemistry, Materials Chemistry, Molecule, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract: The design of metalloporphyrins has attracted the attention of scientists owing to their valuable properties. In this work, the synthesis of meso-tetraphenyl porphyrin H2TPP (I), meso-tetraphenylporphyrinato-chromium(III) complex [CrIII(TPP)Cl] (II), and bis(cyano) meso-tetraphenylporphyrinato-chromium(III) complex [K(2 2 2)] [CrIII(TPP)(CN)2] 2.(C7H6O2) (III) was described. The physicochemical properties of (ll)-(IIII) were investigated. X-ray molecular structure of (III) displayed that the crystal lattice of the six-coordinated chromium (III) coordination compound, was made by two-dimensional chain pairs parallel to the [0 1 0] direction sustained by C__H…Cg and Cg…Cg π inter and intra-molecular interactions. Hirshfeld surface analysis allowed us to understand the intermolecular contacts, where the fingerprint plot provided the information about the percentage contribution. UV–vis data showed a red-shift for the chromium complex and slightly blue-shift after coordination with cyano axial ligand. The Eg-op value suggested that (I)-(III) compounds are semi-conductor. The complex (II) efficiently and promptly degraded calmagite dye solution at a yield of 100% (calmagite = 40 mg/L, pH = 6, time = 10 min, catalyst dose = 3 mg, H2O2 dose = 4 mL/L, and T = 20 °C).
Published: 2021
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49. An air-persistent oxyallyl radical cation with simple di(methyl)amino substituents

Author: Christian Philouze, David C. Martin, Florian Molton, Vianney Regnier, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE ), Département de Chimie Moléculaire (DCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Steric effects, 010405 organic chemistry, Chemistry, Metals and Alloys, General Chemistry, 010402 general chemistry, Photochemistry, 01 natural sciences, Catalysis, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Radical ion, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Computational chemistry, Simple (abstract algebra), Materials Chemistry, Ceramics and Composites, Inert gas, ComputingMilieux_MISCELLANEOUS
Abstract: We report an experimental and theoretical study of the 1,1,3,3-tetrakis-di(methylamino)oxyallyl radical cation. Despite simple substituents with minimal steric hindrance, this radical was found to be stable under an inert atmosphere and persistent for several hours in well-aerated solutions.
Published: 2016
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50. Cover Feature: Complexes of the Bis(di‐ tert ‐butyl‐aniline)amine Pincer Ligand: The Case of Copper (Eur. J. Inorg. Chem. 28/2020)

Author: Christian Philouze, Fabrice Thomas, Solène Gentil, Nicolas Leconte, Alan Le Goff, and Florian Molton
Subjects: Inorganic Chemistry, Tert butyl, chemistry.chemical_compound, Aniline, chemistry, Feature (computer vision), chemistry.chemical_element, Cover (algebra), Amine gas treating, Pincer ligand, Medicinal chemistry, Copper
Published: 2020
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