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Raw data for the article: "Identification of a Heteroleptic Pd6L6L′6Coordination Cage by Screening of a Virtual Combinatorial Library" J. Am. Chem. Soc.2021, 143, 4, 1773–1778 DOI: 10.1021/jacs.0c12793

This upload contains the raw data for the article:"LiBF4-Induced Rearrangement and Desymmetrization of a Palladium-Ligand Assembly". Angew. Chem.Int. Ed.2022,61,e202201823 DOI:10.1002/anie.202201823

The enantiopure Schiff bases (R or S)-N-1-(phenyl)ethyl-2,4-X1,X2-salicylaldimine (X1, X2 = Cl, Br, I) coordinate to copper(ii) and provide pseudotetrahedral bis[(S or R)-N-1-(phenyl)ethyl-(2,4-X1,X2-salicylaldiminato-κ2N,O)]-Δ/Λ-Cu(ii) (Λ/Δ-Cu-R or Δ/Λ-Cu-S). An induced Λ and Δ-chirality at-metal centre has been launched along the C2-axis of the molecule. Steric constraints brought by halogen substituents on the coordinating salicylal ring provide diastereoselectively Λ-Cu-R or Δ-Cu-S as major and Δ-Cu-R or Λ-Cu-S as minor diastereomers at solid-state, as evidenced by X-ray crystal structures and PXRD analyses. These results reveal inversion of induced chirality at-metal in comparison to the similar complexes without halogen substituents on the salicylal ring. Electronic circular dichroism (ECD) spectra show mirror-image relationships, confirming enantiomeric excess of the R or S-ligated complexes in solution. Comparisons of experimental and simulated ECD spectra suggest diastereomeric excess of Δ-Cu-R or Λ-Cu-S in solution which correspond to an inversion from the found solid-state Λ-Cu-R or Δ-Cu-S as major diastereomers. In addition, the optimized gas-phase structures also reveal Δ-Cu-R or Λ-Cu-S as slightly more stable than Λ-Cu-R or Δ-Cu-S. Thus, solid-state versus solution (or gas-phase) studies also indicate an interconversion of induced chirality (helicity inversion) at-metal from Λ-Cu-R or Δ-Cu-S to Δ-Cu-R or Λ-Cu-S. Thermal stability increases with the molecular weight of the complexes following ClClBrBrI substituents. Hirshfeld surface analyses explore the strongest halogen (ortho)-halogen (para) interactions between two molecules in Λ-Cu-R3 or Δ-Cu-S3 at a distance shorter than the sum of the van der Waals radii of the two iodine atoms, provide a brilliant red spot on the dnorm surfaces. EPR spectra along with simulation suggest an axial symmetry with gzgx,y2.0 and values for gz/Az ≥ 135 cm indicate pseudotetrahedral geometry for the complexes.

In extension with growing concern to develop new antimicrobial organometallic drugs, an attempt has been made to synthesize five new antimicrobial organotin(IV) carbodithioates with general formula, Me2SnClL (1), Me2SnL2 (2), Et2SnClL (3), Et2SnL2 (4), Bu2SnClL (5), Bu2SnL2 (6), (where L = Sodium 3,4-dihydroisoquinoline-2-(1H)-carbodithioate). Compounds have been synthesized by refluxing organotin(IV) chlorides with ligand in dry toluene for 7-8 h. Compound 1, 3 and 5 exhibited Penta coordination, while 2, 4 and 6 showed hexacoordination in solid state, as evident from the difference obtained between symmetric and asymmetric CSS stretches in IR spectra. Solid-state structures of 1 was further attested by single crystal analysis as distorted trigonal bipyramidal geometry. 1H-, 13C- and 119Sn- NMR spectroscopy was used to assess the geometry of the compounds in solution state. It was observed that 1, 3, 4 and 5 completely dissociated in solution and showed tetrahedral geometry, whereas 2 and 6 exhibit pentacoordinate geometry after partial dissociation in solution. The pronounced activity was observed for all the compounds against five different strains of bacteria.

Trimethyl (1), tributyl (2), and triphenyl tin (3) derivatives of sodium (R)-4-((3R,5R,8R,9S,10S,12S,13R,14S,17R)-3,12-dihydroxy-10,13-dimethyl-hexadecahydro-1H-cyclopenta[a]phenanthren-17-yl)pentanoate (sodium deoxycholate) were synthesized by refluxing sodium deoxycholate with the corresponding triorganotin(IV) chloride in 1 : 1 M ratio. All the three compounds were characterized by elemental analysis, infrared spectroscopy, 1H, 13C, 119Sn NMR, and X-ray diffraction studies. From FT-IR spectra, Δν values proposed bridging or chelating behavior of the ligand. The three compounds gave a trigonal bipyramidal geometry in the solid state and tetrahedral geometry in solution. Single crystal of 1 showed polymeric trigonal bipyramidal geometry. Synthesized compounds obtained were screened for their antimicrobial and antitumor activities against A2780 cell line. Results revealed that only 2 showed significant antibacterial activity. However, all the three compounds exhibited promising antifungal and anticancer a...

Complexes with general formula p,t-[Ru(CO)(PR3)(tren)]X2 [R = Ph (1) or p-tol (2); tren = tris(2-aminoethyl)amine; X = Cl- or PF6-] were prepared from [RuCl2(CO)(dmf)(PR3)] by direct reaction with tren. The complexes were fully characterized by NMR (1H, 31P{1H}, HMBC 1H-31P), FTIR and ESI-MS spectroscopy, elemental analysis and the structures of p,t-[Ru(CO)(PPh3)(tren)](PF6)2 (1•PF6) and p,t-[Ru(CO)(P{p-tol}3)(tren)]Cl2 (2•Cl) were determined by X-ray diffraction. The water soluble complexes 1•Cl and 2•Cl were tested as antimicrobial agents against Gram (+) and Gram (-) bacteria with the latter showing superior activity than the approved antimicrobial agent chloramphenicol in one of the strains.

The synthesis of topologically complex structures such as links and knots is one of the current challenges in supramolecular chemistry. The so called Solomon link consists of two doubly interlocked rings. Despite being a rather simple link from a topological point of view only few molecular versions of this link have been described so far. Here we report the quantitative synthesis of a giant molecular Solomon link from 30 subcomponents. The highly charged structure is formed by assembly of 12 cis blocked Pt2+ complexes six Cu+ ions and 12 rigid N donor ligands. Each of the two interlocked rings is composed of six repeating Pt(ligand) units while the six Cu+ ions connect the two rings. With a molecular weight of nearly 12 kDa and a diameter of 44.2 Å this complex is the largest non DNA based Solomon link described so far. Furthermore it represents a molecular version of a "stick link". © 2014 WILEY VCH Verlag GmbH Co. KGaA Weinheim.

The isomerization dynamics of five labile octahedral Co(II) compounds have been investigated by variable temperature and pressure 1H and 19F NMR spectroscopy in dichloromethane solution. The X-ray crystal structure of the two tris-chelates, [Co(HFA)2bpic] (1) and [Co(TTFA)2bpy] (2), show a distorted octahedral arrangement of the 4 oxygen and 2 nitrogen donor atoms, with bidentate ligand bite angles smaller than 90. On the other hand, in the three bis-chelates, trans(N)-[Co(HFA)2(CH3py)2](3), cis(N)-cis(CF3)-trans(S)-[Co(TTFA)2(CH3py)2](4), and trans(N)-trans(CF3)-[Co(TTFA)2(CF3py)2](5), the replacement of the bidentate nitrogen donor ligands by two monodentate Rpy ligands leads to relaxed structures with almost regular octahedral arrangements of the donor atoms (HFA= 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato anion; TTFA= 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionato anion; bpy=2,20-bipyridine; bpic=4,40-dimethyl-2,20-bipyridine). In solution the five complexes are stereolabile and all possible isomers are formed: from one for 1 up to five for 4 and 5. All cis-N isomers form pairs of enantiomers, whereas the trans-N isomers are achiral. A solid state structure/isomerization mechanism/rate correlation has been established for the isomerization dynamics of these Co(II) tris- and bis-chelates. The two tris-chelate complexes 1 and 2, with a distorted octahedral solid state structure, show one and three isomers in solution and isomerize/tautomerize very rapidly according to Bailar twist mechanisms. The three bis-chelate complexes 3, 4, and 5, with a close to octahedral symmetry in the solid state, show two, five, and five isomers, respectively. They isomerize/tautomerize 3 orders of magnitude slower as the tris-chelates, by an intramolecular dissociative mechanism involving a ring-opening of an arm of a bidentate ligand to form a TBP intermediate with a dangling bidentate ligand. The results of this first systematic investigation of the isomerization mechanisms of highly labile Co(II) complexes are supported by the NMR observed exchange paths (up to five for complexes for 4 and 5), the variable temperature (185 to 312 K) and pressure (up to 200 MPa) activation parameters, and a detailed analysis of the solid state structures.

Herein we report a series of charged iridium complexes emitting from near-UV to red using carbene-based (NC)-C-boolean AND: ancillary ligands. Synthesis, photophysical and electrochemical properties of this series are described in detail together with X-ray crystal structures. Density Functional Theory calculations show that the emission originates from the cyclometallated main ligand, in contrast to commonly designed charged complexes using bidentate (NN)-N-boolean AND ancillary ligands, where the emission originates from the ancillary (NN)-N-boolean AND ligand. The radiative process of this series of compounds is characterized by relatively low photoluminescence quantum yields in solution that is ascribed to non-radiative deactivation of the excited state by thermally accessible metal-centered states. Despite the poor photophysical properties of this series of complexes in solution, electroluminescent emission from the bluish-green to orange region of the visible spectrum is obtained when they are used as active compounds in light-emitting electrochemical cells.

Metal complexes bearing phosphine ligands are attracting increasing attention for their applications in medicinal chem. In particular, organometallic ruthenium-phosphine complexes have been found to exhibit promising antitumor activity. The synthesis, anticancer activity and reactivity of a novel bis-phosphine complex, [Ru(η6-cymene)(PPh2(o-C6H4O)-κ2-P,O)(pta)]Cl (pta = 1,3,5-triaza-7-phosphatricyclo[3.3.1.1.]decane), is presented. The complex appears to exhibit its anticancer effect via a different mechanism to other ruthenium-arene pta complexes with labile co-ligands.

Thirteen palladium-ligand assemblies with different structures and topologies were investigated for the ability to bind lithium ions. In one case, the addition of LiBF4 resulted in a profound structural rearrangement, converting a dincluclear [Pd2L4]2 complex into a low-symmetry [Pd4L8]8+ assembly with two binding pockets for solvated LiBF4 ion pairs. The rearrangement could only be induced by Li+, indicating highly specific host-guest interaction. A structural analysis of the [Pd4L8]8+ receptor revealed a compact structure with multiple intramolecular interactions, reminiscent of what is seen for natural and synthetic foldamers.

The use of crystal engineering to control the supramolecular arrangement of pi-conjugated molecules in the solid-state is of considerable interest for the development of novel organic electronic materials. In this study, we investigated the effect of combining of two types of supramolecular interaction with different geometric requirements, amide hydrogen bonding and pi-interactions, on the pi-overlap between calamitic pi-conjugated cores. To this end, we prepared two series of bithiophene diesters and diamides with methylene, ethylene, or propylene spacers between the bithiophene core and the functional groups in their terminal substituents. The hydrogen-bonded bithiophene diamides showed significantly denser packing of the bithiophene cores than the diesters and other known alpha,omega-disubstituted bithiophenes. The bithiophene packing density reach a maximum in the bithiophene diamide with an ethylene spacer, which had the smallest longitudinal bithiophene displacement and infinite 1D arrays of electronically conjugated, parallel, and almost linear N-H center dot center dot center dot O=C hydrogen bonds. The synergistic hydrogen bonding and pi-interactions were attributed to the favorable conformation mechanics of the ethylene spacer and resulted in H-type spectroscopic aggregates in solid-state absorption spectroscopy. These results demonstrate that the optoelectronic properties of pi-conjugated materials in the solid-state may be tailored systematically by side-chain engineering, and hence that this approach has significant potential for the design of organic and polymer semiconductors.

Reactions of the dinuclear ruthenium complex [(p-cymene)Ru(mu-Cl)3RuCl(C2H4)(PCy3)] with phenylacetylene or tert-butylacetylene gave the vinylidene complexes [(p-cymene)Ru(mu-Cl)3RuCl(=C=CHR)(PCy3)] (R = tBu, Ph), which were characterized crystallographically. With acetylene, however, a tetranuclear -carbide complex was obtained as evidenced by single-crystal X-ray analysis as well as by solid-state NMR spectroscopy. Experiments with fully 13C-labelled acetylene showed that acetylene was the carbon source for the carbide ligand.

Crystalline thin films of pi-conjugated molecules are relevant as the active layers in organic electronic devices. Therefore, materials with enhanced control over the supramolecular arrangement, crystallinity, and thin-film morphology are desirable. Herein, it is reported that hydrogen-bonded substituents serve as additional structure-directing elements that positively affect crystallization, thin-film morphology, and device performance of p-type organic semiconductors. It is observed that a quaterthiophene diacetamide exhibits a denser packing than that of other quaterthiophenes in the single-crystal structure and, as a result, displays enhanced intermolecular electronic interactions. This feature was preserved in crystalline thin films that exhibited a layer-by-layer morphology, with large domain sizes and high internal order. As a result, organic field-effect transistors of these polycrystalline thin films showed mobilities in the range of the best mobility values reported for single-crystalline quaterthiophenes. The use of hydrogen-bonded groups may, thus, provide an avenue for organic semiconducting materials with improved morphology and performance.

Organic-inorganic metal-halide perovskite solar cells (PSCs) have achieved a certified power-conversion efficiency (PCE) of 25.5%. However, long-term stability and air stability of the PSCs are still major concerns and hamper commercialization. Herein, we employ a multi-functional ionic liquid (IL), 1,3-bis(cyanomethyl)imidazolium bis(trifluoromethylsulfonyl)imide ([Bcim][TFSI]), which contains an imidazolium cation functionalized with nitrile (CN) groups and the TFSI anion and is, additionally, able to form an extensive network of low-barrier H bonds, as an additive in perovskite-precursor solutions. Because of a combination of the Lewis-basic CN groups and the hydrophobic TFSI anion in the IL, highly crystalline perovskite films with large grain sizes are obtained. The IL-modified perovskite films afford PSCs with long-term stability and PCEs > 21%. The stability of unencapsulated devices retain >95% of their original efficiency after 1,000 h of aging. This study demonstrates the considerable potential of TFSI-based ILs to improve the performance of PSCs.

It took only 11 years for the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to increase from 3.8% to 25.2%. It is worth noting that, as a new thin-film solar cell technique, defect passivation at the interface is crucial for the PSCs. Decorating and passivating the interface between the perovskite and electron transport layer (ETL) is an effective way to suppress the recombination of carriers at the interface and improve the PCE of the device. In this work, several acceptor-donor-acceptor (A-D-A) type fused-ring organic semiconductors (FROS) with indacenodithiophene (IDT) or indacenodithienothiophene (IDDT) as the bridging donor moiety and 1,3-diethyl-2-thiobarbituric or 1,1-dicyromethylene-3-indanone as the strong electron-withdrawing units, were deposited on the SnO2 ETL to prepare efficient planar junction PSCs. The PCEs of the PSCs increased from 18.63% for the control device to 19.37%, 19.75%, and 19.32% after modification at the interface by three FROSs. Furthermore, impedance spectroscopy, steady-state and time-resolved photoluminescence spectra elucidated that the interface decorated by FROSs enhance not only the extraction of electrons but also the charge transportation at the interface between the perovskite and ETL. These results can provide significant insights in improving the perovskite/ETL interface and the photovoltaic performance of PSCs.

Compounds that combine metal-based drugs with covalently linked targeted organic agents have been shown, in some instances, to exhibit superior anticancer properties compared to the individual counterparts. Within this framework, we prepared a series of organometallic ruthenium(II)- and osmium(II)-p-cymene complexes modified with the nonsteroidal anti-inflammatory drugs (NSAIDs) indomethacin and diclofenac. The NSAIDs are attached to the organometallic moieties via monodentate (pyridine/phosphine) or bidentate (bipyridine) ligands, affording piano-stool Ru(II) and Os(II) arene complexes of general formula [M(eta(6)-p-cymene)Cl-2(N)], where N is a pyridine-based ligand, {2-(2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indo1-3-yl) acetoxy) ethyl-3-(pyridin-3-yl)propanoate} or {2-(2-(24(2,6-dichlorophenyl)amino)-phenyl)acetoxy)ethyl-3-(pyridin-3-71)propanoate}, [M(eta(6)-p-cymene)Cl-2(P)], where P is a phosphine ligand, {2-(2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yOacetoxy)ethyl-(diphenylpho sphanyl) benzo ate} or {2- (2- (2-((2,6-dichlorophenyl) amino)phenyl) acetoxy) ethyl-4-(diphenylphosphanyl)-benzoate, and [M(eta(6)-p-cymene)Cl(N,N')][Cl], where N,N' is a bipyridine-based ligand, (4'-methyl-[2,2'-bipyridin]-4-yOmethyl-2-(1-(4-chlorob enzoyl)-5-methoxy-2-methyl-1H-in dol-3-yl) acetate), (4'-methyl- [2,2'-bipyridin]-4-yl) methyl-2-(2-((2,6-dichlorophenyl) amino)phenyl) acetate), (bis (2- (2- (1- (4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indo1-3-71)acetoxy)-ethyl)[2,2'-bipyridine]-5,5'-dicarboxylate), or (bis(2-(2-(24(2,6-dichlorophenyl)amino)phenyl)acetoxy)ethyl)[2,2'-bipyridine]-5,5'-dicarboxylate). The antiproliferative properties of the complexes were assessed in human ovarian cancer cells (A2780 and A2780cisR, the latter being resistant to cisplatin) and nontumorigenic human embryonic kidney (HEK-293) cells. Some of the complexes are considerably more cytotoxic than the original drugs and also display significant cancer cell selectivity.

The strongly chelating anionic beta-diketiminate ligand has been employed to formulate complexes involving almost every metal of the periodic table; however, the heavier metals of the d block remain relatively unexplored. This paper describes the synthesis and characterization of the first two osmium, beta-diketiminato compounds, including a coordinatively unsaturated cationic complex. In parallel to the analogous Ru(II) complexes, the cationic (eta(6)-arene)osmium(II) complex demonstrates bifunctional behavior through [4 + 2] cycloaddition with ethylene, cleavage of dihydrogen under mild conditions, and protonation/chloride addition with [Et2OH]Cl. Metal-centered activity in both the Ru(II) and Os(II) beta-diketiminates has until now remained elusive, as the cationic Os complex is shown to readily coordinate an aryl isonitrile. The applicability of Os(II) beta-diketiminato complexes in catalytic olefin hydrogenation demonstrates significantly greater activity in terms of conversion and TOF for a range of substrates, including styrene, cyclohex-1-ene, and 1-methylcyclohex-1-ene. Moreover, selective hydrogenation of the exocyclic alkenyl group in limonene was observed, whereas the corresponding isostructural Ru(II) complexes are inactive. In contrast, the cationic (eta(6)-arene)ruthenium(II) beta-diketiminato complex proved more active for the catalytic dehydrogenation of N,N-dimethylamine borane (Me2NBH3) than the equivalent Os(II) species. A detailed DFT study of the Ru(II) and Os(II) beta-diketiminato species using charge decomposition analysis (CDA) demonstrates differences in metal ligand interactions, which in turn considerably influences the extent of bifunctional reactivity.

© 2015 American Chemical Society. Direct coupling of alkyl halides with terminal alkynes provides an efficient and streamlined access to alkyl substituted alkynes which are important synthetic intermediates biologically active molecules and organic materials. However until nowthere have been fewer than a handful of catalytic methods available for this reaction and detailed mechanistic studies have not been reported. Herein we describe the design and development a new nickel pincer complex that catalyzes the direct coupling of primary alkyl halides with terminal alkynes at room temperature. The catalysis has a good substrate scope and high functional group tolerance. Kinetic data suggest that the new pincer ligand is hemilabile and the dissociation of a labile amine donor is the turnover determining step of the catalysis. An intermediate Ni alkynyl species has been isolated and structurally characterized. The reactivity of this species gives insight into the nature of the active species for the activation of alkyl halide.

Thorium redox chemistry is extremely scarce due to the high stability of ThIV. Here we report two unique examples of thorium arenide complexes prepared by reduction of a ThIV-siloxide complex in presence of naphthalene, the mononuclear arenide complex [K(OSi(OtBu)3)3Th(η6-C10H8)] (1) and the inverse-sandwich complex [K(OSi(OtBu)3)3Th]2(μ-η6,η6-C10H8)] (2). The electrons stored in these complexes allow the reduction of a broad range of substrates (N2O, AdN3, CO2, HBBN). Higher reactivity was found for the complex 1 which reacts with the diazoolefin IDipp=CN2 to yield the unexpected ThIV amidoalkynyl complex 5 via a terminal N-heterocyclic vinylidene intermediate. This work showed that arenides can act as convenient redox-active ligands for implementing thorium-ligand cooperative multielectron transfer and that the reactivity can be tuned by the arenide binding mode.

Reaction of Ln(III) with a tetrakis(diketone) ligand H4L [1,1?-(4,4?-(2,2-bis((4-(4,4,4-trifluoro-3-oxobutanoyl) phenoxy)methyl)propane-1,3-diyl)bis(oxy)bis(4,1-phenylene))bis(4,4,4-trifluorobutane-1,3-dione)] gives new podates which, according to mass spectral data and Sparkle/AM1 calculations, can be described as dimers, (NBu4[LnL])2 (Ln = Eu, Tb, Gd:Eu), in both solid-state and dimethylformamide (DMF) solution. The photophysical properties of the EuIII podate are compared with those of the mononuclear diketonate (NBu4[Eu(BTFA)4], BTFA = benzoyltrifluoroacetonate), the crystal structure of which is also reported. The new EuIII dimeric complex displays bright red luminescence upon irradiation at the ligand-centered band in the range of 250?400 nm, irrespective of the medium. The emission quantum yields and the luminescence lifetimes of (NBu4[EuL])2 (solid state: 51% ± 8% and 710 ± 2 ms; DMF: 31 ± 5% and 717 ± 1 ms) at room temperature are comparable to those obtained for NBu4[Eu(BTFA)4] (solid state: 60 ± 9% and 730 ± 5 ms; DMF: 30 ± 5% and 636 ± 1 ms). Sparkle/AM1 calculations were utilized for predicting the ground-state geometries of the EuIII dimer. Theoretical Judd?Ofelt and photoluminescence parameters, including quantum yields, predicted from this model are in good agreement with the experimental values, proving the efficiency of this theoretical approach implemented in the LUMPAC software (http://lumpac.pro.br). The kinetic scheme for modeling energy transfer processes show that the main donor state is the ligand triplet state and that energy transfer occurs on both the 5D1 (44.2%) and 5D0 (55.8%) levels. Furthermore, the newly obtained EuIII complex was doped into a PMMA matrix to form highly luminescent films and one-dimensional nanowires having emission quantum yield as high as 67%-69% (doping concentration = 4% by weight); these materials display bright red luminescence even under sunlight, so that interesting photonic applications can be foreseen

Applying additives to perovskite precursor solutions is an effective way to passivate perovskite films for the construction of perovskite solar cells (PSCs) with increased power-conversion efficiencies (PCEs) and enhanced stabilities. Ionic liquids (ILs) with halide anions have been applied as additives. Here, we report the application of imidazolium-based ILs, containing the nitrile functionality in the cation and chloride anion, as additives for triple-cation (Cs+, formamidinium [FA(+)], methylammonium [MA(+)]) PSCs. We found that a Cl-I exchange takes place between the I- anion of the triple-cation precursors and the Cl- anion of the IL. The fabricated PSCs containing perovskite films with the ILs show high PCEs (in the best case 22.86%) and high stabilities, with the unencapsulated devices retaining about 95% of their original efficiencies after 1,000 h. The mechanistic basis for the passivation effect of the IL additives in the perovskite films is described.

Isomerization and olefin exchange experiments show that β-H elimination is kinetically viable but thermodynamically unfavorable in [(MeNN2)Ni-alkyl] complexes. The intermediacy of Ni-hydride species was corroborated by a trapping experiment. The alkyl complex [(MeNN2)Ni-propyl] catalyzes olefin isomerization.

The utilization of large ligands in coordination-based self-assembly represents an attractive strategy for the construction of supramolecular assemblies more than two nanometers in size. However, the implementation of this strategy is hampered by the fact that the preparation of such ligands often requires substantial synthetic effort. Herein, we describe a simple one-step protocol, which allows large bipyridyl ligands with a bent shape to be synthesized from easily accessible and/or commercially available starting materials. The ligands were used to construct PdII2L4-type coordination cages of unprecedented size. Furthermore, we provide evidence that these cages may be stabilized by close intramolecular packing of lipophilic ligand side chains. Packing effects of this kind are frequently encountered in protein assemblies, but they are seldom used as a design element in metallasupramolecular chemistry.

Clathrochelate complexes of cobalt are known in the oxidation states I, II, and III. Low-valent Co(I) complexes are highly reactive compounds, and there is only limited knowledge about their structures in the solid state. Herein, we describe the crystallographic analyses of three low-valent clathrochelate complexes, along with analyses of the corresponding Co(II) precursors. Two different ligand environments were studied: a) ligands with alkyl substituents, which render the complexes highly reducing, and b) potentially redox non-innocent ligands. Our analyses show that the ligands have a large effect on the redox potentials, but only a small effect on the geometry and the electronic state of the central Co ion.

Nine 1,3-dichlorobenzene congeners were selected as model compds. to assess the relative rates of proton abstraction from 4- and 5-positions ("ortho" vs. "meta" metalation). Using lithium 2,2,6,6-tetramethylpiperidide as the basic reagent, the chlorine-adjacent 4-position underwent metalation exclusively. In contrast, attack at the chlorine-remote 5-position became significant even in the case of moderately sized 2-substituents (such as dimethylamino or ethyl) when sec-butyllithium was employed. The "ortho/para" (4-/5-) ratios ranged from 80:20 to 65:35. The more pronounced "meta-orienting" effect of silicon as opposed to carbon substituents can be attributed to dissimilarities in the pi polarization of the arom. ring. [on SciFinder (R)]

A series of half-sandwich pentamethylcyclopentadienyl rhodium(III) and iridium(III) complexes [Cp*M(DBM/ HDB/AVB)Cl] and [Cp*M(DBM/HDB/AVB)(PTA)]-[SO3CF3], where Cp* = pentamethylcyclopentadienyl, the proligands DBMH = dibenzoylmethane, HDBH = o-hydroxydi-benzoylmethane, AVBH = avobenzone, and PTA = 1,3,5-triaza-7-phosphaadamantane, is reported. All the complexes were characterized by IR, H-1 and C-13 NMR spectroscopy, electrospray ionization mass spectrometry, elemental analysis, and DFT calculations. Five of the complexes have also been characterized in the solid-state by X-ray crystallography. The cytotoxicity of the complexes has been evaluated against human ovarian A2780 and A2780cisR cell lines and, with the only exception of complexes 1 and 2 that display a negligible cytotoxicity, exhibit moderate cytotoxicity toward both cancer cell lines. However, the complexes do not show cancer cell selectivity with respect to human embryonic kidney HEK293 cells.

Here we report the effect of UO2+⋯Fe2+ cation–cation interactions on the redox properties of uranyl(V) complexes and on their stability with respect to proton induced disproportionation. The tripodal heptadentate Schiff base trensal3− ligand allowed the synthesis and characterization of the uranyl(VI) complexes [UO2(trensal)K], 1 and [UO2(Htrensal)], 2 and of uranyl(V) complexes presenting UO2+⋯K+ or UO2+⋯Fe2+ cation–cation interactions ([UO2(trensal)K]K, 3, [UO2(trensal)] [K(2.2.2crypt)][K(2.2.2crypt)], 4, [UO2(trensal)Fe(py)3], 6). The uranyl(V) complexes show similar stability in pyridine solution, but the presence of Fe2+ bound to the uranyl(V) oxygen leads to increased stability with respect to proton induced disproportionation through the formation of a stable Fe2+–UO2+–U4+ intermediate ([UO2(trensal)Fe(py)3U(trensal)]I, 7) upon addition of 2 eq. of PyHCl to 6. The addition of 2 eq. of PyHCl to 3 results in the immediate formation of U(IV) and UO22+ compounds. The presence of an additional UO2+ bound Fe2+ in [(UO2(trensal)Fe(py)3)2Fe(py)3]I2, 8, does not lead to increased stability. Redox reactivity and cyclic voltammetry studies also show an increased range of stability of the uranyl(V) species in the presence of Fe2+ with respect both to oxidation and reduction reactions, while the presence of a proton in complex 2 results in a smaller stability range for the uranyl(V) species. Cyclic voltammetry studies also show that the presence of a Fe2+ cation bound through one trensal3− arm in the trinuclear complex [{UO2(trensal)}2Fe], 5 does not lead to increased redox stability of the uranyl(V) showing the important role of UO2+⋯Fe2+ cation–cation interactions in increasing the stability of uranyl(V). These results provide an important insight into the role that iron binding may play in stabilizing uranyl(V) compounds in the environmental mineral-mediated reduction of uranium(VI).

A new procedure for the synthesis of highly substituted 1,3-diaminopyrazoles is described. As substrates, we have employed 1-alkynyltriazenes and imines. The formation of pyrazoles was achieved by two-fold C–N coupling reactions in the presence of (JohnPhos)AuCl and AgNTf2 as catalyst precursors. The regioselectivity of the reaction was inferred from a crystallographic analysis of one reaction product.

To investigate the effect of different halogen substituents and leaving groups and the flexibility of ligands on the anticancer activity of copper complexes, sixteen copper(ii) complexes with eight different tridentate Schiff-base ligands containing pyridine and 3,5-halogen-substituted phenol moieties were synthesized and characterized by spectroscopic methods. Four of these complexes were also characterized by X-ray crystallography. The cytotoxicity of the complexes was determined in three different tumor cell lines (i.e. the A2780 ovarian, HCT116 colorectal and MCF7 breast cancer cell line) and in a normal primary fibroblast cell line. Complexes were demonstrated to induce a higher loss of cell viability in the ovarian carcinoma cell line (A2780) with respect to the other two tumor cell lines, and therefore the biological mechanisms underlying this loss of viability were further investigated. Complexes with ligand L-1 (containing a 2-pycolylamine-type motif) were more cytotoxic than complexes with L-2 (containing a 2-(2-pyridyl)ethylamine-type motif). The loss of cell viability in A2780 tumor cells was observed in the order Cu(Cl-2-L-1)NO3 > Cu(Cl-2-L-1)Cl > Cu(Br-2-L-1)Cl > Cu(BrCl-L-1)Cl. All complexes were able to induce reactive oxygen species (ROS) that could be related to the loss of cell viability. Complexes Cu(BrCl-L-1)Cl and Cu(Cl-2-L-1)NO3 were able to promote A2780 cell apoptosis and autophagy and for complex Cu(BrCl-L-1)Cl the increase in apoptosis was due to the intrinsic pathway. Cu(Cl-2-L-1)Cl and Cu(Br-2-L-1)Cl complexes lead to cellular detachment allowing to correlate with the results of loss of cell viability. Despite the ability of the Cu(BrCl-L-1)Cl complex to induce programmed cell death in A2780 cells, its therapeutic window turned out to be low making the Cu(Cl-2-L-1)NO3 complex the most promising candidate for additional biological applications.

The conversion of metal nitrides to NH3 is an essential step in dinitrogen fixation, but there is limited knowledge of the reactivity of nitrides with protons (H+). Herein, we report comparative studies for the reactions of H+ and NH3 with uranium nitrides, containing different types of ancillary ligands. We show that the differences in ancillary ligands, leads to dramatically different reactivity. The nitride group, in nitride-bridged cationic and anionic diuranium(iv) complexes supported by -N(SiMe3)(2) ligands, is resistant toward protonation by weak acids, while stronger acids result in ligand loss by protonolysis. Moreover, the basic -N(SiMe3)(2) ligands promote the N-H heterolytic bond cleavage of NH3, yielding a "naked" diuranium complex containing three bridging ligands, a nitride (N3-) and two NH2 ligands. Conversely, in the nitride-bridged diuranium(iv) complex supported by -OSi((OBu)-Bu-t)(3) ligands, the nitride group is easily protonated to afford NH3, which binds the U(iv) ion strongly, resulting in a mononuclear U-NH3 complex, where NH3 can be displaced by addition of strong acids. Furthermore, the U-OSi((OBu)-Bu-t)(3) bonds were found to be stable, even in the presence of stronger acids, such as NH4BPh4, therefore indicating that -OSi((OBu)-Bu-t)(3) supporting ligands are well suited to be used when acidic conditions are required, such as in the H+/e(-) mediated catalytic conversion of N-2 to NH3.

Functionalized imidazolium iodide salts (ionic liquids) modified with -CH2-CH=CH2, -CH2C equivalent to CH, or -CH2C equivalent to N groups are applied as dopants in the synthesis of CH3NH3PbI3-type perovskites together with a fumigation step. Notably, a solar cell device prepared from the perovskite film doped with the salt containing the -CH2-CH=CH2 side-chain has a power conversion efficiency of 19.21%, which is the highest efficiency reported for perovskite solar cells involving a fumigation step. However, doping with the imidazolium salts with the -CH2C equivalent to CH and -CH2C equivalent to N groups result in perovskite layers that lead to solar cell devices with similar or lower power conversion efficiencies than the dopant-free cell.

Despite the excellent photovoltaic properties achieved by perovskite solar cells at the laboratory scale, hybrid perovskites decompose in the presence of air, especially at high temperatures and in humid environments. Consequently, high-efficiency perovskites are usually prepared in dry/inert environments, which are expensive and less convenient for scale-up purposes. Here, a new approach based on the inclusion of an in situ polymerizable ionic liquid, 1,3-bis(4-vinylbenzyl)imidazolium chloride ([bvbim]Cl), is presented, which allows perovskite films to be manufactured under humid environments, additionally leading to a material with improved quality and long-term stability. The approach, which is transferrable to several perovskite formulations, allows efficiencies as high as 17% for MAPbI(3)processed in air % relative humidity (RH) >= 30 (from an initial 15%), and 19.92% for FAMAPbI(3)fabricated in %RH >= 50 (from an initial 17%), providing one of the best performances to date under similar conditions.

The three-component reaction of aryl boronic acids with 1,2,4,5-tetrahydroxybenzene and 1,2-bis(4-pyridyl)ethylene or 4,4-bipyridine leads to the formation of dark-purple boronate ester polymers. Crystallographic analyses show that the polymer strands have a zig-zag geometry, and the bis(dioxaborole) units are connected by dipyridyl linkers through dative B-N interactions. Upon dissolution of the polymers in hot chloroform, most of the B-N connections are broken, which indicates that polymer formation is a reversible process. A computational study provides evidence that the strong color of the polymers is due to efficient intrastrand charge-transfer excitations from the tetraoxobenzene to the dipyridyl linker.

NiII complexes of the new pincer amidobis(amine) ligand are described. The Ni chloride complex catalyzes Kumada-Corriu-Tamao coupling of unactivated alkyl halides with alkyl Grignard reagents, as well as double C-C coupling of CH2Cl2 with alkyl Grignard reagents (see schemes). The synthesis, properties, and reactivity of nickel(II) complexes of a newly developed pincer amidobis(amine) ligand (MeNN2) are described. Neutral or cationic complexes [(MeNN2)NiX] (X=OTf (6), OC(O)CH3 (7), CH3CN (8), OMe (9)) were prepared by salt metathesis or chloride abstraction from the previously reported [(MeNN2)NiCl] (1). The Lewis acidity of the {(MeNN2)Ni} fragment was measured by the 1H NMR chemical shift of the coordinated CH3CN molecule in 8. Electrochemical measurements on 1 and 8 indicate that the electron-donating properties of NN2 are similar to those of the analogous amidobis(phosphine) (pnp) ligands. The solid-state structures of 6-8 were determined and compared to those of 1 and [(MeNN2)NiEt] (3). In all complexes, the MeNN2 ligand coordinates to the NiII ion in a mer fashion, and the square-planar coordination sphere of the metal is completed by an additional donor. The coordination chemistry of MeNN2 thus resembles that of other three-dentate pincer ligands, for example, pnp and arylbis(amine) (ncn). Reactions of 2 with alkyl monohalides, dichlorides, and trichlorides were investigated. Selective CC bond formation was observed in many cases. Based on these reactions, efficient Kumada-Corriu-Tamao coupling of unactivated alkyl halides and alkyl Grignard reagents with 1 as the precatalyst was developed. Good yields were obtained for the coupling of primary and secondary iodides and bromides. Double C-C coupling of CH2Cl2 with alkyl Grignard reagents by 1 was also realized. The scope and limitations of these transformations were studied. Evidence was found for a radical pathway in Ni-catalyzed C-C cross-coupling reactions, which involves NiII alkyl intermediates.

The hexanuclear [Na12Fe6(tris-cyclo-salophen)(2)(THF)(14)], 1-THF, and the trinuclear [Na6Fe3(tris-cyclo-salophen)(py)(9)], 1-py, Fe(II) clusters can be easily assembled in one step from the ligand-based reduction of the [FeII(salophen)(THF)] complex. These complexes consist of triangular cores where three Fe(II) ions are held together, within range of bonding interaction, by the hexa-amide, hexaphenolate macrocyclic ligand tris-cyclo-salophen(12-). The tris-cyclo-salophen(12-) ligand is perfectly suited for binding three Fe(II) centers at short distances, allowing for strong magnetic coupling between the Fe(II) centers. The macrocyclic ligand is generated by the reductive coupling of the imino groups of three salophen ligands, resulting in three new C-C bonds. The six electrons stored in the ligand become available for the reduction of carbon dioxide with selective formation of carbonate.