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13,14-diphenyldibenzo[b,j][4,7]phenanthroline (DBP3) in various solvents was studied by time-resolved fluorescence and fs transient absorption (fs-TA) spectroscopy. An intramolecular benzene excimer is demonstrated to form within DBP3; it exhibits strong redshifted emission with maximum at 540–640 nm. "Intrinsic" fluorescence from DBP3 is dramatically quenched down to τ = 50–400 fs in all the solvents studied. Fs-TA and time-resolved fluorescence spectra have proved that relaxed intramolecular benzene excimer is formed from S1 state via hot excimer state with three lifetime components: 50 fs, ∼3.5 ps, and ∼25 ps, which are of the inertial (electronic) and diffusive parts of the relaxation due to solute–solvent interaction. Formation of triplet states via intersystem crossing was observed directly from the upper excited electronic states of DBP3. [ABSTRACT FROM AUTHOR]

This is a comprehensive study of the photophysical behaviour of heteroleptic iridium(III) complexes with imidazo[4,5-f][1,10]phenanthroline (imphen) as an ancillary ligand, represented by the general formula [Ir(N∩C)2(imphen)]PF6. As cyclometalating ligands, 2-phenylpyridine (Hppy), 2-phenylquinoline (Hpquin), 2-phenylbenzothiazole (Hpbztz), and 2-(2-pyridyl)benzothiophene (pybzthH) were used. The impact of structural modifications of cyclometalating ligands was widely explored by a combination of steady-state and time-resolved optical techniques accompanied by theoretical calculations. We evidenced that the cyclometalating ligands induce essential changes in the nature of the emissive excited state and the emission characteristics of [Ir(N∩C)2(imphen)]PF6. While the complex [Ir(ppy)2(imphen)]PF6 (1) is a typical 3MLLCT emitter, the lowest triplet states of [Ir(pquin)2(imphen)]PF6 (2), [Ir(pbztz)2(imphen)]PF6 (3) and [Ir(pybzth)2(imphen)]PF6 (4) have a predominant 3LCN∩C character. The phosphorescence colour of the investigated Ir(III) complexes changes from greenish-yellow to red, their quantum yields vary from 56 to 2%, and their triplet excited-state lifetimes fall in the 743–3840 ns range. The highest photoluminescence quantum yield was revealed for 2 in CH2Cl2, while complex 3 in MeCN shows the most pronounced increase in the lifetime. Both complexes 2 and 3 show an increased efficiency of singlet oxygen generation. The herein discussed structure–property relationships are of high significance for controlling photoinduced processes in heteroleptic iridium(III) complexes with the imphen-based ancillary ligand, and making further progress in effectively tuning the emission energies, quantum yields and excited-state lifetimes of these systems by structural modifications of cyclometalating ligands, especially the π-conjugation, the position of the N-donor and the presence of sulfur heteroatoms. [ABSTRACT FROM AUTHOR]

Hydrogen boride (HB) nanosheets are recognized as a safe and lightweight hydrogen carrier, yet their hydrogen (H2) generation technique has been limited. In the present study, nitrogen‐containing organic heterocycles are mixed with HB nanosheets in acetonitrile solution for visible‐light‐driven H2 generation. After exploring various nitrogen‐containing heterocycles, the mixture of 1,10‐phenanthroline molecules (Phens) and HB nanosheets exhibited significant H2 generation even under visible light irradiation. The quantum efficiency for H2 generation of the mixture of HB nanosheets and Phens is 0.6%. Based on spectroscopic and electrochemical analyses and density functional theory (DFT) calculations, it is determined that radical species generated from Phens with electrons and protons donated by HB nanosheets are responsive to visible light for H2 generation. The HB nanosheets/Phens mixture presented in this study can generate H2 using renewable energy sources such as sunlight without the need for complex electrochemical systems or heating mechanisms and is expected to serve as a lightweight hydrogen storage/release system. [ABSTRACT FROM AUTHOR]

This paper presents the synthesis and application of a novel catalyst for carbon–carbon bond formations, comprising palladium immobilized on 2-(5-hydroxyquinolin-8-yl)-1H-benzo[d]imidazole-5-carboxylic acid modified superparamagnetic iron oxide nanoparticles (Pd@HQBI-SPION). The synthesis involved the attachment of HQBI ligands to SPION using APTES, followed by the immobilization of palladium. Characterization techniques, including FTIR, TEM, and magnetic measurements, confirmed the successful synthesis and structural integrity of Pd@HQBI-SPION. The catalytic activity of Pd@HQBI-SPION was evaluated in various carbon–carbon bond formation reactions, demonstrating high efficiency and reusability. 8 different derivatives bearing several electron withdrawing and electron donating functionalities were used as starting materials and the products were obtained in high isolated yields (75–97%). The catalyst exhibited excellent performance in one-pot synthesis of phenanthroline-dimedone polycyclic derivatives via C-alkylation followed by intramolecular O-alkylation of phenanthroline with dimedone. The products are obtained in high to excellent yields is described. This protocol presents a highly selective synthetic method for the construction of polycyclic aromatic compounds containing nitrogen and oxygen atoms. [ABSTRACT FROM AUTHOR]

A new heterometallic complex of CoII and NdIII with phenathroline [Co(Phen)3][Nd(NO3)5(H2O)][Nd(NO3)4(H2O)2]⋅H2O was synthesized for the first time by the self-assembly method. The crystal structure of the complex was determined by X-ray crystallography. The compound is an anion-cation complex and crystallizes in the monoclinic space group P21/n with unit cell parameters à=12.4251(4) Å, b=11.7206(3) Å, c=36.5374(12) Å, α=γ=900, β=90.581(3)0 . In the crystalline phase, the complex is in the form of a crystal hydrate with a composition of 1:1. The anionic part of the complex consists of two nitrate hydrated NdIII complexes: [Nd(NO3)5(H2O)][Nd(NO3)4(H2O)2]–, in which the coordination number of neodymium is 11 and 10, respectively. The [Co(Phen)3]3+ ion is a cationic part of the complex in which the CoII atom has a distorted CoN6 octahedral environment, bidentately coordinating three phenanthroline molecules. Due to intermolecular hydrogen bonds (N–H⋅⋅⋅O, O–H⋅⋅⋅O), a three-dimensional supramolecular architecture is formed in the crystal, in which the polymer layers are packed parallel along the crystallographic axis a. [ABSTRACT FROM AUTHOR]

Five new lanthanide MOFs were prepared by solvothermal synthesis to investigate the effect of ligand and pillar length using the unsymmetrical mixed-donor ligands L1H (4′-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-[1,1′-biphenyl]-3-carboxylic acid) and L2H (3-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)benzoic acid) and linear pillaring ligands H2BDC (terephthalic acid) and H2BPDC (3,4-dihydro-[1,1′-biphenyl]-4,4′-dicarboxylic acid). Nd-MOF1 and Gd-MOF1, [M(BDC)(L2)]2.5DMA (M = Nd or Gd), were isomorphous. They both presented a 3D pillared framework with bcu topology with a paddlewheel SBU and sinusoidal channels. Nd-MOF2, [Nd(BDC)(L1)]·4DMA, has a pseudo-paddlewheel SBU and formed a 3D pillared pcu framework where 1D double-chains were crosslinked with BDC to provide sinusoidal channels. Gd-MOF2, [Gd2(BPDC)2(L1)2]·9DMA·0.25H2O, has a pseudo-paddlewheel SBU and the 1D double-chains were cross-linked by BPDC to form a regular pcu 3D network which was interpenetrated and has sinusoidal channels. The solvent rich Nd-MOF3, [Nd2(BPDC)(L1)2(DMA)4](OH)2·10DMA, has a pseudo-paddlewheel SBU and formed 1D double-chains which were partially cross linked by BPDC to form a 2D sheet. The bound DMA solvent prevented the extension of these sheets into a 3D framework. Interestingly, the double chains do not interfere with the adoption of a regular topology by the networks. The sinusoidal channels appeared to be a consequence of the unsymmetrical nature of the L1H and L2H ligands. [ABSTRACT FROM AUTHOR]

The title compound, [Sn(C6H5)Cl3(C12H8N2)], which was obtained by the reaction between 1,10-phenanthroline and phenyltin trichloride in methanol, exhibits intramolecular hydrogen-bonding interactions involving the chlorine and hydrogen atoms. Crystal cohesion is ensured by intermolecular C—H...Cl hydrogen bonds, as well as Y—X...π and π-stacking interactions involving three different aromatic rings with centroid–centroid distances of 3.6605 (13), 3.9327 (14) and 3.6938 (12) A˚ ]. Hirshfeld surface analysis and the associated two-dimensional fingerprint plots reveal significant contributions from H...H (30.7%), Cl...H/H...Cl (32.4%), and C...H/H...C (24.0%) contacts to the crystal packing while the C...C (6.2%), C...Cl/Cl...C (4.1%), and N...H/ H...N (1.7%) interactions make smaller contributions. [ABSTRACT FROM AUTHOR]

Mitochondrial quality control is finely tuned bymitophagy, the selective degradation of mitochondria through autophagy, and mitochondrial biogenesis. Removal of damaged mitochondria is essential to preserve cellular bioenergetics and prevent detrimental events such as sustained mitoROS production, pro-apoptotic cytochrome c release or mtDNA leakage. The array of tools available to study mitophagy is very limited but in constant development. Almost a decade ago, we developed a method to assess mitophagy flux using MitoTracker Deep Red in combination with lysosomal inhibitors. Now, using the novel tandem-fluorescence reporter mito-QC (mCherry-GFP-FIS1101-152) that allows to differentiate between healthy mitochondria (mCherry+GFP+) and mitolysosomes (mCherry+GFP-), we have developed a robust and quantitative method to assess mitophagy by flow cytometry. This approach has been validated in ARPE-19 cells using PINK1/Parkindependent (CCCP) and PINK1/Parkin-independent (DFP) positive controls and complementary techniques. Furthermore, we show that the mito-QC reporter can be multiplexed, especially if using spectral flow cytometry, to simultaneously study other cellular parameters such as viability or ROS production. Using this technique, we evaluated and characterized two prospective mitophagy inducers and further dissected their mechanism of action. Finally, using mito-QC reporter mice, we developed a protocol to measure mitophagy levels in the retina ex vivo. This novel methodology will propelmitophagy research forward and accelerate the discovery of novel mitophagy modulators. [ABSTRACT FROM AUTHOR]

The title compound, [Sn(C6H5)Cl3(C12H8N2)], which was obtained by the reaction between 1,10-phenanthroline and phenyl­tin trichloride in methanol, exhibits intra­molecular hydrogen-bonding inter­actions involving the chlorine and hydrogen atoms. Crystal cohesion is ensured by inter­molecular C--H⋯Cl hydrogen bonds, as well as Y--X⋯π and π-stacking inter­actions involving three different aromatic rings with centroid-centroid distances of 3.6605 (13), 3.9327 (14) and 3.6938 (12) Å]. Hirshfeld surface analysis and the associated two-dimensional fingerprint plots reveal significant contributions from H⋯H (30.7%), Cl⋯H/H⋯Cl (32.4%), and C⋯H/H⋯C (24.0%) contacts to the crystal packing while the C⋯C (6.2%), C⋯Cl/Cl⋯C (4.1%), and N⋯H/H⋯N (1.7%) inter­actions make smaller contributions. [ABSTRACT FROM AUTHOR]

The synthesis as well as the structural, optical and computational characterization of seven new highly hindered homoleptic copper(I) phenanthroline complexes (namely C1–C7) is reported along with the comparison with the benchmark derivatives. Despite limited steric hindrance in direct proximity of the copper(I) coordination site, X‐ray structures show that the higher hindered derivatives of the series display a more optimal tetrahedral geometry with minimal D2 symmetry distortion. A novel remote control of the geometry, with steric hindrance away from the coordination site, leads to a favorable arrangement as demonstrated by structural and computational data. In addition, electrochemical and steady‐state and time‐resolved photophysical studies are presented which further support the beneficial effects on the ground‐state redox and excited‐state properties when both remote and close steric effects are exploited. Indeed, both an increase of the photoluminescence quantum yield and a prolongation of the excited state lifetime is observed for the highly‐substituted derivative C6 compared to benchmark counterparts on account of the reduced excited‐state flattening distortions imparted by the additional steric constraints. [ABSTRACT FROM AUTHOR]

Recently, attention has turned to drugs like salicylamide for treating COVID-19. Several studies have reported simple, fast, and sensitive methods for measuring salicylamide levels. However, potential limitations remain regarding interference from other drugs and accuracy of results. To tackle this issue, researchers combined the standard addition technique with flow injection analysis. As part of this investigation, the reaction involving Fe (III), salicylamide, and 1,10-phenanthroline at a temperature of 55°C was examined using a spectrophotometer set at a wavelength of 528 nm. Thus, the new design was able to show an excellent linearity over the concentration range of (2-30 μg/mL) and (25-300 μg/mL), with correlation coefficients (r² ) of 0.9669 and 0.9781, respectively. In addition, physical and chemical variables were optimized to obtain the best results. There was a significant positive correlation between the new design and SCÏO NIR micro-spectrometers device (handheld) outcomes. [ABSTRACT FROM AUTHOR]

The crystal structures of two coordination compounds, (acetato‐κO)(2,2′‐bipyridine‐κ2N,N′)(1,10‐phenanthroline‐κ2N,N′)copper(II) acetate hexahydrate, [Cu(C2H3O2)(C10H8N2)(C12H8N2)](C2H3O2)·6H2O or [Cu(bipy)(phen)Ac]Ac·6H2O, and (acetato‐κO)bis(2,2′‐bipyridine‐κ2N,N′)copper(II) acetate–acetic acid–water (1/1/3), [Cu(C2H3O2)(C10H8N2)2](C2H3O2)·C2H4O2·3H2O or [Cu(bipy)2Ac]Ac·HAc·3H2O, are reported and compared with the previously published structure of [Cu(phen)2Ac]Ac·7H2O (phen is 1,10‐phenanthroline, bipy for 2,2′‐bipyridine, ac is acetate and Hac is acetic acid). The geometry around the metal centre is pentacoordinated, but highly distorted in all three cases. The coordination number and the geometric distortion are both discussed in detail, and all complexes belong to the space group P. The analysis of the geometric parameters and the Hirshfeld surface properties dnorm and curvedness provide information about the metal–ligand interactions in these complexes and allow comparison with similar systems. [ABSTRACT FROM AUTHOR]

Abstract This paper presents the synthesis and application of a novel catalyst for carbon–carbon bond formations, comprising palladium immobilized on 2-(5-hydroxyquinolin-8-yl)-1H-benzo[d]imidazole-5-carboxylic acid modified superparamagnetic iron oxide nanoparticles (Pd@HQBI-SPION). The synthesis involved the attachment of HQBI ligands to SPION using APTES, followed by the immobilization of palladium. Characterization techniques, including FTIR, TEM, and magnetic measurements, confirmed the successful synthesis and structural integrity of Pd@HQBI-SPION. The catalytic activity of Pd@HQBI-SPION was evaluated in various carbon–carbon bond formation reactions, demonstrating high efficiency and reusability. 8 different derivatives bearing several electron withdrawing and electron donating functionalities were used as starting materials and the products were obtained in high isolated yields (75–97%). The catalyst exhibited excellent performance in one-pot synthesis of phenanthroline-dimedone polycyclic derivatives via C-alkylation followed by intramolecular O-alkylation of phenanthroline with dimedone. The products are obtained in high to excellent yields is described. This protocol presents a highly selective synthetic method for the construction of polycyclic aromatic compounds containing nitrogen and oxygen atoms.

The title compound, [Sn(C6H5)Cl3(C12H8N2)], which was obtained by the reaction between 1,10-phenanthroline and phenyltin trichloride in methanol, exhibits intramolecular hydrogen-bonding interactions involving the chlorine and hydrogen atoms. Crystal cohesion is ensured by intermolecular C—H...Cl hydrogen bonds, as well as Y—X...π and π-stacking interactions involving three different aromatic rings with centroid–centroid distances of 3.6605 (13), 3.9327 (14) and 3.6938 (12) Å]. Hirshfeld surface analysis and the associated two-dimensional fingerprint plots reveal significant contributions from H...H (30.7%), Cl...H/H...Cl (32.4%), and C...H/H...C (24.0%) contacts to the crystal packing while the C...C (6.2%), C...Cl/Cl...C (4.1%), and N...H/H...N (1.7%) interactions make smaller contributions.

Fe(III)-0.5-AP-CN photocatalysts synthesized based on a donor–acceptor structure can significantly enhance the yield of N 2 reduction to NH 3. [Display omitted] • Donor-acceptor (D-A) polymeric carbon nitride constructed by covalent binding of phenanthroline units. • Intermolecular charge transfer in the presence of D-A structure promotes the rapid migration of photogenerated carriers. • Phenanthroline units in the D-A structure are coordinated with Fe3+ ions to form special nanowire morphologies. • D-A type Fe(III)-0.5-AP-CN photocatalytic synthesis of ammonia with yields up to 825.3 μmol g−1 h−1. Constructing photocatalysts for the stable and efficient production of NH 3 is of excellent research significance and challenging. In this paper, the electron acceptor 5-amino-1,10-phenanthroline (AP) is introduced into the electron-donor graphitic carbon nitride (CN) framework by a simple heated copolymerization method to construct a donor–acceptor (D-A) structure. Subsequently, the phenanthroline unit is coordinated with transition metal Fe3+ ions to obtain the photocatalyst Fe(III)-0.5-AP-CN with better nitrogen fixation performance, and the average NH 3 yield can reach 825.3 μmol g−1 h−1. Comprehensive experimental results and theoretical calculations show that the presence of the D-A structure can induce intramolecular charge transfer, effectively separating photogenerated electrons and holes. The Fe active sites can improve the chemisorption energy for N 2 , enhance the N -Fe bonding, and better activate the N 2 molecule. Therefore, the synergistic effect between the construction of the D-A structure and the stably dispersed Fe active sites can enable CN to achieve high-performance N 2 reduction to produce NH 3. [ABSTRACT FROM AUTHOR]

Pyridinic N functionalized DEB-N 2 displays strong O 2 adsorption ability and delivers a substantial H 2 O 2 generation with an initial rate of 3492 μmol g-1h−1 in pure water. [Display omitted] Artificial photosynthesis of hydrogen peroxide (H 2 O 2) is a hopeful alternative to the industrial anthraquinone process. However, rational fabrication of the photocatalysts for the production of H 2 O 2 without any sacrificial agents is still a formidable challenge. Herein, two kinds of linear conjugated polymers (LCPs) including pyridinic N functionalized polymer (DEB-N 2) and pyridinic N non-contained polymer (DEB-N 0) were successfully synthesized. DEB-N 2 displays enhanced light capturing ability and good dispersion in water, leading to a substantial initial H 2 O 2 generation rate of 3492μmol g-1h−1 as well as remarkable photocatalytic stability in pure water. Furthermore, the temperature programmed desorption (TPD) and density functional theory (DFT) analysis reveal that highly electronegative pyridine-N atoms in DEB-N 2 boost the adsorption affinity of oxygen molecules, which facilitates the occurrence of the oxygen reduction reaction, therefore enhancing the performance of photocatalytic H 2 O 2 production. This study unveils that the presence of pyridinic N in DEB-N 2 has a significant impact on photocatalytic H 2 O 2 production, suggesting the precise manipulation of the chemical structure of polymer photocatalysts is essential to achieve efficient solar-to-chemical energy conversion. [ABSTRACT FROM AUTHOR]

Here we report a protocol for the preparation of 1,4‐diketones from 1,2‐disubstituted cyclobutanols based on their ring‐opening oxidation with molecular oxygen. The reaction proceeds under manganese catalysis in the presence of 1,10‐phenanthroline ligand and leads to the target product along with minor 4‐hydroxyketone that can be oxidized with Dess‐Martin periodinane in the same reaction vessel. Substrates with alkyl and aryl substituents including those bearing functional groups were successfully engaged in the reaction. [ABSTRACT FROM AUTHOR]

Room temperature phosphorescence carbon dots (RTP CDs) are one of the newly investigated nanomaterials because of their remarkable optical characteristics. They are widely utilized in many versatile optoelectronic and security applications. Apart from synthesis, one of its challenging attributes is its lifetime at room temperature. Here, a straightforward and quick heating approach is presented for synthesizing self‐matrix 1,10 phenanthroline and boron‐based RTP CDs. 1,10 phenanthroline is utilized as an aromatic and hetero atom containing carbon precursor and boric acid is used as a passivating to stabilize the triplet excitons and prevent nonradiative deactivation. Various characterization techniques like TEM, XRD, FTIR, UV–vis, PL, and elemental analysis (ICP and CHNS) have been used to study the properties of self‐matrix RTP CDs. The RTP CDs exhibited excellent blue‐green emission when excited at 302 nm. Compared to the available literature, the novelty of this work is observed from its high naked eye phosphorescence characteristic of ≈22 s with an average lifetime of ≈ 2.4 s at 302 nm, making them ultralong self‐matrix RTP CD material. Due to their exceptional qualities, the self‐matrix RTP CDs have been widely employed for various applications, including information encryption decryption, phosphor for LEDs, anticounterfeiting, and water sensitivity analysis. [ABSTRACT FROM AUTHOR]

Two new europium coordination compounds, [Eu2(papip)2(PhCOO)6] and [Eu2(phpip)2(PhCOO)6] (papip is 1-phenyl-2-(4-aminophenyl)imidazo[4,5-f][1,10]phenanthroline and phpip 1-phenyl-2-(4-hydroxyphenyl)imidazo[4,5-f][1,10]phenanthroline), have been synthesized hydrothermally and structurally characterized, involving the in situ hydrolysis of phenylacetonitrile to phenylacetate. The –NH2 group in the former complex was unexpectedly generated from the –NO2 group of free 1-phenyl-2-(4-nitrophenyl)imidazo[4,5-f][1,10]phenanthroline during the reaction process, representing the first such transformation in a hydrothermal reaction. Both complexes exhibit bright red photoemission typical of Eu(III) f–f transition under UV excitation, with long excited state lifetimes and quite high photoluminescence quantum yields. [ABSTRACT FROM AUTHOR]

The bonding effects between 3d transition‐metal single sites and supports originate from crystal field stabilization energy (CFSE). The 3d transition‐metal atoms of the spontaneous geometrical distortions, that is the Jahn–Teller effect, can alter CFSE, thereby leading to the Irving–Williams series. However, engineering single‐atom sites (SASs) using the Irving–Williams series as an ideal guideline has not been reported to date. Herein, alkynyl‐linked covalent phenanthroline frameworks (CPFs) with phenanthroline units are developed to anchor the desired 3d single metal ions from d5 to d10 (Mn2+, Fe3+, Co2+, Ni2+, Cu2+, and Zn2+). The Irving–Williams series was employed to accurately predict the bonding effects between 3d transition‐metal atoms and phenanthroline units. To verify this, theoretical calculations and experimental results reveal that Cu‐SASs/CPFs exhibits higher stability and faster charge‐transfer efficiency, far surpassing other metal‐SASs/CPFs. As expected, Cu‐SASs/CPFs demonstrates a high photoreduction of CO2‐to‐CO activity (~30.3 μmol ⋅ g−1 ⋅ h−1) and an exceptional photooxidation of CH3CHO‐to‐CH3COOH activity (~24.7 μmol ⋅ g−1 ⋅ h−1). Interestingly, the generated *O2− is derived from the process of CO2 reduction, thereby triggering a CH3CHO oxidation reaction. This work provides a novel design concept for designing SASs by the Irving–Williams to regulate the catalytic performances. [ABSTRACT FROM AUTHOR]

Chiral imidazolidin-2-ones are a kind of important N-heterocycles in bioactive molecules and can be converted to valuable chiral vicinal diamines. It is of great significance to develop catalytic asymmetric transformations for the synthesis of chiral N -heterocycles which play a significant role in drug development. Herein, an asymmetric intramolecular C(sp³)--H amination of N-benzoyloxyurea via 1,5-hydrogen atom transfer (HAT) is developed by using earth-abundant iron as the catalyst and chiral amino-acid derived phenanthroline as ligand, affording a series of chiral imidazolidinones in moderate-to-good yields (up to 68%) and enantiomeric ratios (up to 81:19). It is worth noting that this is one of the very few examples of iron-catalyzed enantioselective intramolecular C(sp³)--H aminations realized with a nonenzymatic catalyst. [ABSTRACT FROM AUTHOR]

A new mesoporous Mn(II)‐MOF [Mn2(phen)2(nia)2]∞ with 4‐c uninodal net topology and reiterating rectangular channels in its cargo‐net like extension was synthesized using π‐conjugated phenanthroline (phen) and syn‐syn bridging 5‐nitroisopthalic acid (nia) linkers. The MOF (1) exhibited phase purity, uniform morphology, photo and thermal stability, and robustness; duly triggered by the exceptional framework rigidity via intermolecular H‐bonding and interlayer π–π stacking interactions. The bright‐blue luminescence of the MOF nano‐dispersion was explored for sensitive, specific and ultrafast detection of trinitrophenol (TNP) with extremely low LOD (90.62 nM), high KSV (18.27×104 M−1) and Kq (4×1014 M−1s−1). The vapor‐phase TNP sensing was also accomplished. Additionally, 1 served towards discriminatory, aqueous‐phase monitoring of Cr(VI)‐oxoanions, depicting LODs: 36.08 and 35.70 ppb; KSV: 3.46×104 and 4.87×104 M−1; Kq: 3.26×1013 M−1s−1 and 4.31×1013 M−1s−1; and response time: 32 and 40s for CrO42− and Cr2O72− respectively. The quenching mechanisms (i. e., RET, PET, IFE, weak interactions, collisional quenching and π⋅⋅⋅π stacking) was explained from several experimental investigations and theoretical DFT calculations. The recyclable sensing events and quantification from complex environmental matrices with admirable recovery rates and high KSV (13.02–22.44×104; ~6.31–10.98×104 and ~6.60–11.42×104 M−1 for TNP, CrO42− and Cr2O72−) undoubtedly advocated the consistency of the probe. [ABSTRACT FROM AUTHOR]

Platinum‐based chemotherapeutic agents are widely used in the treatment of cancer. However, their effectiveness is limited by severe adverse reactions, drug resistance, and poor water solubility. This study focuses on the synthesis and characterization of new water‐soluble cationic monofunctional platinum(II) complexes starting from the [PtCl(η1‐C2H4OEt)(phen)] (1, phen=1,10‐phenanthroline) precursor, specifically [Pt(NH3)(η1‐C2H4OEt)(phen)]Cl (2), [Pt(1‐hexyl‐1H‐imidazole)(η1‐C2H4OEt)(phen)]Cl (3), and [Pt(1‐hexyl‐1H‐benzo[d]imidazole)(η1‐C2H4OEt)(phen)]Cl (4), which deviate from traditional requirements for antitumor activity. These complexes were evaluated for their cytotoxic effects in comparison to cisplatin, using immortalized cervical adenocarcinoma cells (HeLa), human renal carcinoma cells (Caki‐1), and normal human renal cells (HK‐2). While complex 2 showed minimal effects on the cell lines, complexes 3 and 4 demonstrated higher cytotoxicity than cisplatin. Notably, complex 4 displayed the highest cytotoxicity in both cancer and normal cell lines. However, complex 3 exhibited the highest selectivity for renal tumor cells (Caki‐1) among the tested complexes, compared to healthy cells (HK‐2). This resulted in a significantly higher selectivity than that of cisplatin and complex 4. Therefore, complex 3 shows potential as a leading candidate for the development of a new generation of platinum‐based anticancer drugs, utilizing biocompatible imidazole ligands while demonstrating promising anticancer properties. [ABSTRACT FROM AUTHOR]

Three new ruthenium(II) polypyridyl complexes containing α‐diimine ligands, namely, carbonylhydrido(1,10‐phenanthroline‐κ2N,N)bis(triphenylphosphine‐κP)ruthenium(II) hexafluorophosphate, [RuH(C12H8N2)(C18H15P)2(CO)]PF6, carbonylhydrido(2,9‐dimethyl‐1,10‐phenanthroline‐κ2N,N)bis(triphenylphosphine‐κP)ruthenium(II) hexafluorophosphate, and carbonylhydrido(4,7‐dimethyl‐1,10‐phenanthroline‐κ2N,N)bis(triphenylphosphine‐κP)ruthenium(II) hexafluorophosphate, both [RuH(C14H12N2)(C18H15P)2(CO)]PF6, were synthesized and characterized by spectroscopic and X‐ray diffraction methods. In these complexes, the ruthenium(II) ion adopts a distorted octahedral geometry. There are no intermolecular hydrogen bonds in the crystal structures of the analysed complexes and Hirshfeld surface analysis showed that the H...H contacts constitute a high percentage, close to 50%, of the intermolecular interactions. [ABSTRACT FROM AUTHOR]

1,10‐Phenanthroline d‐ or f‐metal complexes can be utilised in biomedical applications such as imaging or therapeutics. Herein, we designed bimetallic d‐block metal‐phenanthroline f‐block metal‐1,4,7,10‐tetraazacyclododecane‐1,4,7,1,0‐tetraacetic acid (DOTA) conjugates as theranostic agents to simultaneously achieve both of these applications. Luminescence studies show the 1,10‐phenanthroline‐Eu(III)‐DOTA complexes displayed an off/on/off pH‐dependent switch, demonstrating their potential as pH‐responsive lanthanide luminescence probes. Relaxometry studies showed that the 1,10‐phenanthroline‐Gd(III)‐DOTA complexes present a r1 of 5.15±0.05 mM−1 s−1 and could thus be used as magnetic resonance (MR) contrast agents. Complexation of Pt(II) by the 1,10‐phenanthroline moiety resulted in quenching of the Eu(III) luminescence, but an enhancement of the Gd(III) relaxivity (r1=7.53±0.69 mM−1 s−1). Cell viability studies of the d–f hybrids in a cancer cell line showed the potential of these complexes as anticancer agents, as the IC50 for the Pt(II)/Gd(III) complex (IC50=24.9 μM) was lower than that of cisplatin (IC50=31.6 μM). As such, Pt(II)‐1,10‐phenanthroline‐Gd(III)‐DOTA complexes are promising theranostic agents for cancer therapy. [ABSTRACT FROM AUTHOR]

In this study, the 4,9 diazafluoren-9-one ligand and [Y(Daf)2Cl3.OH2] complex were synthesized. The interaction of this complex with DNA and bovine serum albumin (BSA) was investigated by UV-vis and fluorescence spectroscopy. The molecular docking method was used to confirm the experimental results, investigate the type of interaction, and determine the binding site. The binding constant and Stern -- Volmer constant were calculated using spectroscopy techniques. The binding constant of the Y-complex with DNA and BSA obtained using the UV-vis technique was 1.61 × 105 M-1 and 0.49 × 105 M-1, while that obtained using the fluorescence method was 3.39 × 105 M-1 and 3.63 × 105 M-1, respectively. The results of experimental and theoretical data showed that the interaction between the yttrium complex and DNA and BSA is driven by the hydrogen bond and van der Waals interaction, respectively. The yttrium complex communicates with DNA via the groove interaction. This complex has high binding energy with bovine serum albumin. In addition, the molecular docking results showed that the complex binds to the IIA subdomain of BSA (site I). Finally, anticancer activity of the yttrium complex was studied on MCF-7 and A549 cell lines by using the MTT method. The IC50 values obtained showed that the yttrium complex possesses anticancer activity. [ABSTRACT FROM AUTHOR]

A vanadium(IV) Schiff base complex derived from salicylaldehyde and L-alanine with phenanthroline as co-ligand viz. [VIVO(salala)(phen)]1.66H2O (where salala = Schiff base derived from salicylaldehyde and L-alanine, phen = 1,10-phenanthroline) have been synthesized and its structure determined by single crystal X-ray diffraction. The crystal lattice parameters of the complex was determined by single crystal X-ray diffraction with lattice parameters, a = 18.4361 [5] Å, b = 22.4926 [6] Å, c = 12.4035 [6] Å, β = 126.904 [1]°, C2 space group, Z = 2. In the crystal, the V(IV) ions are in distorted octahedral geometry, coordinated to two oxygen atoms and one nitrogen atom of Schiff base ligand and two phenanthroline nitrogen atoms. The π···π stacking interactions as well as C–H···O hydrogen bonds were found to play an important role in the self-assembly of the complex molecules. The non-covalent interactions of the complex were further evaluated by Hirshfeld Surface Analysis. Spectroscopic characterization of the complex by Infrared and UV–visible spectroscopic techniques is also reported. Crystal structure of a vanadium(IV) Schiff base complex derived from salicylaldehyde and L-alanine with phenanthroline as co-ligand have been determined by single crystal X-ray diffraction and non-covalent interactions between the complex molecules studied by Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen boride (HB) nanosheets are recognized as a safe and lightweight hydrogen carrier, yet their hydrogen (H2) generation technique has been limited. In the present study, nitrogen‐containing organic heterocycles are mixed with HB nanosheets in acetonitrile solution for visible‐light‐driven H2 generation. After exploring various nitrogen‐containing heterocycles, the mixture of 1,10‐phenanthroline molecules (Phens) and HB nanosheets exhibited significant H2 generation even under visible light irradiation. The quantum efficiency for H2 generation of the mixture of HB nanosheets and Phens is 0.6%. Based on spectroscopic and electrochemical analyses and density functional theory (DFT) calculations, it is determined that radical species generated from Phens with electrons and protons donated by HB nanosheets are responsive to visible light for H2 generation. The HB nanosheets/Phens mixture presented in this study can generate H2 using renewable energy sources such as sunlight without the need for complex electrochemical systems or heating mechanisms and is expected to serve as a lightweight hydrogen storage/release system.

Bu çalışmada, bilinen Ni(II) ditiyofosfonato kompleksinden Lewis bazı içerikli yeni fenantrolin Ni(II)ditiyofosfonato kompleksi sentezlendi. İyonik yapıda kompleks paramanyetik özelliğe sahiptir. Sentezlenen koordinasyon bileşiğinin yapısı elementel analiz, manyetik duyarlılık ölçümleriyle beraber, FT-IR ve kütle spektroskopisi ölçümleriyle de aydınlatılmıştır.

Using the established synthetic methods, aroyl-S,N-ketene acetals and subsequent bi- and multichromophores can be readily synthesized. Aside from pronounced AIE (aggregation induced emission) properties, these selected examples possess distinct complexometric behavior for various metals purely based on the underlying structural motifs. This affects the fluorescence properties of the materials which can be readily exploited for metal ion detection and for the formation of different metal-aroyl-S,N-ketene acetal complexes that were confirmed by Job plot analysis. In particular, gold(I), iron(III), and ruthenium (III) ions reveal complexation enhanced or quenched emission. For most dyes, weakly coodinating complexes were observed, only in case of a phenanthroline aroyl-S,N-ketene acetal multichromophore, measurements indicate the formation of a strongly coordinating complex. For this multichromophore, the complexation results in a loss of fluorescence intensity whereas for dimethylamino-aroyl-S,N-ketene acetals and bipyridine bichromophores, the observed quantum yield is nearly tripled upon complexation. Even if no stable complexes are formed, changes in absorption and emission properties allow for a simple ion detection. [ABSTRACT FROM AUTHOR]

The complex [VONargPhenCl] (Narg, naringin; phen = 1,10-phenanthroline) was synthesized and characterized. Comparative analysis with the binary complex, [VO(Narg)2], revealed improvements in both antioxidant and anticancer effects upon replacing one Narg ligand with Phen. The new complex behaved as a better antioxidant against reactive oxygen species (ROS) and displayed higher cytotoxicity (against the A549 human lung cancer cell line, 24 h incubation) compared to the ligands and the binary complex. This increased cytotoxic effect was associated with intracellular ROS generation and GSH/GSSG depletion, indicating an oxidative stress mechanism. Additional observations, such as the depletion of mitochondrial membrane potential and morphological changes, suggested the involvement of an intrinsic apoptotic pathway. Furthermore, the complex exhibited enhanced cellular uptake of vanadium compared to the binary complex. The complex demonstrated spontaneous interaction with bovine serum albumin and the binding constant values indicated its ability to be transported by this protein. This study underscores the significance of incorporating a compound with π-electronic delocalization into the coordination sphere of the oxidovanadium(IV) cation that improves the antioxidant capacity. Moreover, its lipophilic characteristics impart an improved transport across the cellular membrane and enhance the pro-oxidant effects in cancer cells, ultimately enhancing the anticancer actions of the metal complex. [ABSTRACT FROM AUTHOR]

The development of fluorescent materials that can act as sensors for the determination of metal ions in biological fluids is important since they show, among others, high sensitivity and specificity. However, most of the molecules that are used for these purposes possess a very low solubility in aqueous media, and, thus, it is necessary to adopt some derivation strategies. Clay minerals, for example, hectorite, as natural materials, are biocompatible and available in large amounts at a very low cost that have been extensively used as carrier systems for the delivery of different hydrophobic species. In the present work, we report the synthesis and characterization of a hectorite/phenanthroline nanomaterial as a potential fluorescent sensor for Zn ion detection in water. The interaction of phenanthroline with the Ht interlaminar space was thoroughly investigated, via both theoretical and experimental studies (i.e., thermogravimetry, FT-IR, UV-vis and fluorescence spectroscopies and XRD measurements), while its morphology was imaged by scanning electron microscopy. Afterwards, the possibility to use it as sensor for the detection of Zn2+ ions, in comparison to other metal ions, was investigated through fluorescent measurements, and the stability of the solid Ht/Phe/Zn complex was assessed by different experimental and theoretical measurements. [ABSTRACT FROM AUTHOR]

Three neutral nickel(II) complexes of 3,5–dibromo–salicylaldehyde (3,5–diBr–saloH) were synthesized in the presence or absence of 1,10–phenanthroline (phen) or its derivative 2,9–dimethyl–1,10–phenanthroline (neoc) as co–ligands, namely [Ni(3,5–diBr–salo)2(neoc)] (complex 1), [Ni(3,5–diBr–salo)2(phen)] (complex 2) and [Ni(3,5–diBr–salo)2(H2O)2] (complex 3), and were characterized by various techniques. The crystal structure of [Ni(3,5–diBr–salo)2(neoc)] was determined by single-crystal X-ray crystallography. According to employed studying techniques, the complexes interact tightly with calf-thymus DNA by an intercalative fashion. Furthermore, compounds 1–3 bind tightly and reversibly to human and bovine serum albumin. [ABSTRACT FROM AUTHOR]

Two new Mn(II) and Zn(II) metal–organic compounds of 1,10-phenanthroline and methyl benzoates viz. [Mn(phen)2Cl2]2-ClBzH (1) and [Zn(4-MeBz)2(2-AmPy)2] (2) (where 4-MeBz = 4-methylbenzoate, 2-AmPy = 2-aminopyridine, phen = 1,10-phenanthroline, 2-ClBzH = 2-chlorobenzoic acid) were synthesized and characterized using elemental analysis, TGA, spectroscopic (FTIR, electronic) and single crystal X-ray diffraction techniques. The crystal structure analysis of the compounds revealed the presence of various non-covalent interactions, which provides stability to the crystal structures. The crystal structure analysis of compound 1 revealed the formation of a supramolecular dimer of 2-ClBzH enclathrate within the hexameric host cavity formed by the neighboring monomeric units. Compound 2 is a mononuclear compound of Zn(II) where flexible binding topologies of 4-CH3Bz are observed with the metal center. Moreover, various non-covalent interactions, such as lp(O)-π, lp(Cl)-π, C–H∙∙∙Cl, π-stacking interactions as well as N–H∙∙∙O, C–H∙∙∙O and C–H∙∙∙π hydrogen bonding interactions, are found to be involved in plateauing the molecular self-association of the compounds. The remarkable enclathration of the H-bonded 2-ClBzH dimer into a supramolecular cavity formed by two [Mn(phen)2Cl2] complexes were further studied theoretically using density functional theory (DFT) calculations, the non-covalent interaction (NCI) plot index and quantum theory of atoms in molecules (QTAIM) computational tools. Synergistic effects were also analyzed using molecular electrostatic potential (MEP) surface analysis. [ABSTRACT FROM AUTHOR]

In this study, a reversible pressure‐sensing material with high sensitivity is presented. Mixed β‐diketonate complexes of Tb3+ and Eu3+ [(Ln)(acac)3phen] are synthesized with phenanthroline as an ancillary ligand. The organic ligands provide the antenna effect to make the Ln3+ complex excitable at 405 nm. Eu3+ emission results from efficient energy transfer (ET) from Tb3+. Under 405 nm excitation, the emission intensity of Tb3+ decreases whereas the emission intensity of Eu3+ increases with pressure, making this complex a potential pressure sensor based on luminescent‐intensity‐ratio (LIR) up to 700 MPa. This study then discusses the application of this Tb3+/Eu3+ complex for pressure sensing depending on measurement conditions. The addition of the optically neutral ion Y3+ to the system can reduce the impact of pressure‐induced structural defects on the emission, thus improving the reversibility of the LIR variation as a function of pressure. Therefore, a self‐calibrating, reliable, and reversible pressure‐sensing material is proposed here, with remarkable pressure sensitivity compared to a peak shift‐based pressure sensor. [ABSTRACT FROM AUTHOR]

Recently, achieving selective cancer therapy with trifling side effects has been a great challenge in the eradication of cancer. Thus, to amplify the cytoselective approach of complexes, herein, we developed a series of Re(I)[2-aryl-1H-imidazo[4,5-f][1,10]phenanthroline] tricarbonyl chloride complexes and screened their potency against HeLa and MCF-7 cell lines together with the evaluation of their toxicity towards a normal kidney cell line (HEK-293). On meticulous investigation, complex [ReI(CO)3Cl(K2-N,N-(2c))] (3c) was found to be the most potent anticancer entity among other complexes. Complex 3c also showed competency to induce apoptosis in MCF-7 cells through G2/M phase cell-cycle arrest in association with the generation of ample reactive oxygen species (ROS), eventually leading to DNA intercalation and internucleosomal cleavage. The order of the cytotoxicity of these complexes depended on their lipophilic character and the electron-withdrawing halogen substitution at the para-position of the phenyl ring in the imidazophenanthroline ligand. [ABSTRACT FROM AUTHOR]

In this study, a set of β‐diketonate samarium(III) complexes–namely, [Sm(TTA)3Phen], [Sm(TTA)3DPEPO], [Sm(TTA)3Bipy], and [Sm(TTA)3Pyra]–has been synthesized and comprehensively characterized. Upon excitation, these complexes exhibit distinct emissions at 566 nm, 610 nm, 650 nm, and 710 nm, respectively, corresponding to the electronic transitions 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2, and 4G5/2→6H11/2. Notably, the most pronounced pinkish‐red emission is associated with the peak at 650 nm. Furthermore, the [Sm(TTA)3DPEPO] complex displays a remarkable photoluminescence quantum yield, reaching up to 15.77 % in a PMMA film matrix. The investigation also involved a prolonged examination lasting over 1200 hours, during which PMMA films doped with the samarium complexes were subjected to humidity and weather conditions to evaluate their photoluminescence stability. The results indicate consistent emissions throughout the humidity test, with an eventual cessation after 1200 hours–except in the case of [Sm(TTA)3Phen] under weather conditions. The enduring emission in this scenario is attributed to the robustness of the phenanthroline ligand, thus highlighting its role in enhancing the durability of the complex. [ABSTRACT FROM AUTHOR]

A new phenanthroline derivative bearing imidazole group, (2-(3,5-di(pyridin-4-yl)phenyl)-1-p-tolyl-1H-imidazo[4,5-f] [1,10]phenanthroline) has been devised. The derivative serves as a multifunctional probe, exhibiting a highly sensitive colorimetric response to Fe2+ ion and a selectively ratiometric fluorescent response to Zn2+ ion in a buffer-ethanol solution. The colorless-to-red visual color change upon addition of Fe2+ accompanied by enhanced absorption makes this derivative a suitable naked-eye sensor for Fe2+ ion. Moreover, the derivative displayed a Zn2+-induced red-shift of emission (44 nm), showing a color change from blue to light cyan under a 365-nm UV lamp. Its practical imaging applicability for intracellular Zn2+ was confirmed in HeLa cells using a confocal microscope. The improved emission properties and cell imaging capability would provide a new approach to fluorescence sensation for Zn2+. [ABSTRACT FROM AUTHOR]

Using the synthesized salt Gd(NCS)3·6H2O, previously unknown mononuclear molecular complexes [Gd(H2O)(bpy)2(NCS)3]·0.5(bpy)·H2O, [Gd(H2O)(phen)2(NCS)3]·phen·0.5H2O as well as ionic ones [Hbpy][Gd(NCS)4(bpy)2]·H2O, [Hphen][Gd(NCS)4(phen)2] (bpy is 2,2'-bipyridine, phen is 1,10-phenanthroline) were prepared. Structural characteristics of the obtained compounds were determined using X-ray diffraction data. The magnetic susceptibility and EPR data of the new Gd complexes are considered taking into account the features of their composition and structure. Due to the peculiarities of the electronic structure, Gd complexes can serve as test systems for analyzing the field strength of ligands and the geometry of the local environment of the 4f-metal ion. It is shown that EPR spectroscopy is highly efficient method for determining the spin Hamiltonian parameters and, consequently, for characterizing the local environment of the gadolinium ion in complexes. However, the EPR method does not allow one to determine the sign of the splitting parameter in the zero field D, which requires additional studies. [ABSTRACT FROM AUTHOR]

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Aims: This study was aimed to characterize laccase from a selected fungal strain and examine the enzyme’s ability to remove lignin from paper pulp. Methodology and results: Twelve fungal strains were screened for laccase production, resulting in the selection of Trichoderma sp. UBDFT12. The highest laccase activity (103 U/L) was observed from the culture filtrate on the fourth day of incubation. The optimum temperature and pH for the enzyme were 40 °C and pH 4, respectively. However, the enzyme stability was found to be reduced with time after 1 h incubation. At 1 mM, it was found that AgNO3, CaCO3, CuSO4, KCl, MgSO4, MnSO4 and ZnSO4 increased the laccase activity to 107, 107, 111, 112, 106, 105 and 107%, respectively, whereas FeSO4 and NH4Cl reduced the activity to 84 and 99%, respectively. The addition of 1% H2O2, 1% NaCl, 1% sodium dodecyl sulphate (SDS), 1 mM ethylenediaminetetraacetic acid (EDTA), 10 mM EDTA, 1 mM phenanthroline and 10 mM phenanthroline reduced the activity to 95, 73, 0, 79, 79, 73 and 37%, respectively. The culture filtrate was partially purified via ammonium sulphate precipitation and the recovered enzyme had a specific activity of 0.176 U/mg. Using sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of the enzyme was approximately 65 kDa and its activity was confirmed by zymography. The culture filtrate was also found to be able to remove lignin from different types of paper pulp. Conclusion, significance and impact of study: Laccase produced by Trichoderma sp. UBDFT12 was found to have the ability to remove lignin from paper pulp. [ABSTRACT FROM AUTHOR]

Exogenous polyamines can elevate postharvest fruit cold resistance and alleviate cold injury. However, the mechanism, by which polyamines mediate cold tolerance, is still to be explored. So in this paper, the conjugated polyamines in tonoplast and vacuole conformation were illuminated in the flesh cells of peach fruit subjected to cold stress, which were pretreated with exogenous putrescine. The results showed that under cold condition, fruit firmness decreased and flesh browning area increased, and vacuole conformation changed. The cold injury could be alleviated by pretreatment with exogenous putrescine, as judged by stabilization of the vacuole conformation, increased fruit firmness and reduced flesh browning area. Furthermore, the cold alleviation was coupled with the increases in the levels of covalently conjugated putrescine and non-covalently conjugated spermidine and spermine in the tonoplast. The results suggested that these conjugated polyamines in tonoplast and vacuole conformation might be involved in putrescine-mediated cold tolerance. The suggestion was further verified by applications with inhibitors, phenanthroline and methylglyoxal-bis (guanylhydrazone) (MGBG). Phenanthroline and MGBG could restrain the putrescine-induced increases in covalently and non-covalently conjugated polyamines mentioned above in the tonoplast, respectively, and increase flesh browning area, decrease fruit firmness and vacuole conformation stabilization. So, we can conclude that exogenous putrescine alleviates cold injury in peach fruit via elevating the contents of the polyamines conjugated to the tonoplast and thereby maintaining vacuole conformation. [ABSTRACT FROM AUTHOR]

Transition metal complexes exhibiting selective toxicity towards a broad range of cancer types are highly desirable as potential anticancer agents. Herein, we report the synthesis, characterization, and cytotoxicity studies of six new mixed-ligand cobalt(III) complexes of general formula [Co(B)2(L)](ClO4)2 (1–6), where B is a N,N-donor phenanthroline base, namely, 1,10-phenanthroline (phen in 1, 2), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq in 3, 4), and dipyrido[3,2-a:2′,3′-c]phenazine (dppz in 5, 6), and L is the monoanion of 8-hydroxyquinoline (HQ in 1, 3, 5) and 5-chloro-7-iodo-8-hydroxyquinoline (CQ in 2, 4, 6). The X-ray single crystal structures of complexes 1 and 2 as PF6− salts revealed a distorted octahedral CoN5O coordination environment. Complexes demonstrated good stability in an aqueous buffer medium and in the presence of ascorbic acid as a reductant. Cytotoxicity studies using a panel of nine cancer cell lines showed that complex 6, with the dppz and CQ ligands, was significantly toxic against most cancer cell types, yielding IC50 values in the range of 2 to 14 μM. Complexes 1, 3, and 5, containing the HQ ligand, displayed lower toxicity compared to their CQ counterparts. The phenanthroline complexes demonstrated marginal toxicity towards the tested cell lines, while the dpq complexes exhibited moderate toxicity. Interestingly, all complexes demonstrated negligible toxicity towards normal HEK-293 kidney cells (IC50 > 100 μM). The observed cytotoxicity of the complexes correlated well with their lipophilicities (dppz > dpq > phen). The cytotoxicity of complex 6 was comparable to that of the clinical drug cisplatin under similar conditions. Notably, neither the HQ nor the CQ ligands alone demonstrated noticeable toxicity against any of the tested cell lines. The Annexin-V-FITC and DCFDA assays revealed that the cell death mechanism induced by the complexes involved apoptosis, which could be attributed to the metal-assisted generation of reactive oxygen species. Overall, the dppz complex 6, with its remarkable cytotoxicity against a broad range of cancer cells and negligible toxicity toward normal cells, holds significant potential for cancer chemotherapeutic applications. [ABSTRACT FROM AUTHOR]

Water-soluble ligands based on a 1,10-phenanthroline core are relatively poorly studied compounds. Developing efficient and convenient syntheses of them would result in new interesting applications because of the importance of 1,10-phenanthrolines. In this manuscript, we describe novel and practical ways to introduce a carboxyl and, for the first time, a phenol and dithiocarboxyl group under mild reaction conditions. This strategy enables highly efficient and practical synthesis of suitable organosulfur compounds with high added value, high chemoselectivity, and a broad substrate range. We present the selective conversion of a hydroxydialdehyde in the form of 10-hydroxybenzo[h]quinoline-7,9-dicarbaldehyde into its derivative, unique hydroxydicarboxylic acid, by an oxidation procedure, giving 10-hydroxybenzo[h]quinoline-7,9-dicarboxylic acid. A similar procedure resulted in the formation of 9-methyl-1,10-phenanthroline-2-carboxylic acid by oxidation of commercially available neocuproine. An alternative method of obtaining 1,10-phenanthroline derivatives possessing carboxylic acid group can be based on the hydrolysis of ester or nitrile groups; however, this synthesis leads to unexpected products. Moreover, we apply Perkin condensation to synthesize a vinyl (or styryl) analog of 1,10-phenanthroline derivatives with phenol function. This reaction also demonstrates a new, simple, and efficient strategy for converting methyl derivatives of 1,10-phenanthroline. We anticipate that the new way of converting methyl will find wide application in chemical synthesis. [ABSTRACT FROM AUTHOR]

Size‐based selectivity for metal ions based on highly preorganized five‐membered chelate rings is discussed. Metal ion complexation by the tetra‐pyridyl ligand EBIP ((8,9‐dihydro‐diquino[8,7‐b:7′,8′‐j][1,10]phenanthroline) is investigated, Formation constants (log K1) are reported for EBIP with 28 metal ions in 50 % CH3OH/H2O (v/v). The shift in size‐selectivity toward large metal ions and against small metal is demonstrated. Log K1 for the EBIP complexes shows a steady increase from La(III) to Lu(III), with a strong local maximum at Sm(III), and strong local minimum at Gd(III). This difference in log K1 between Sm(III) and Gd(III) for the tetra‐pyridyls is shown to depend largely on the level of preorganization of the ligand, being at a maximum for EBIP and a minimum for quaterpyridine. Log K1 for the Y(III) complex is invariably lower than for the similarly‐sized Ho(III) for all ligands that contain any nitrogen donors. Lower log K values for Y(III) are due to stabilization of the Ln(III) complexes with nitrogen donors by participation of the 5d orbitals, and to a lesser extent the 4 f orbitals, of the Ln(III) ions in M−L bonding. A DFT analysis of selectivity of tetra‐pyridyls for metal ions shows that Y(III) complexes should be less stable than similarly‐sized Ho(III) complexes. [ABSTRACT FROM AUTHOR]

Hierarchically graphitic carbon that contained nickel nanoparticles (HGC-Ni (1), (2), and (3)) were prepared by the pyrolysis of three metal complexes as follows: nickel 2,2′-biyridine dichloride, nickel terephthalate 2,2′-bipyridine, and nickel phenanthroline diaqua sulfate, respectively, in the presence of anthracene or pyrene. SEM indicated that the structure of the HGC-Ni samples consisted of nickel nanoparticles with a diameter of 20–500 nm embedded in a thin layer of a hierarchical graphitic carbon layer. The EDAX of HGC-Ni indicated the presence of nickel, carbon, and nitrogen. Chlorine, oxygen, and sulfur were present in (1), (2), and (3), respectively, due to the differences in their complex precursor type. XRD indicated that the nanoparticles consisted of Ni(0) atoms. The turnover frequency (TOF) for the reduction of p-nitrophenol (PNP) increased for catalysts HGC-Ni (3), (2), and (1) and were 0.0074, 0.0094, and 0.0098 mg PNP/mg catalyst/min, respectively. The TOF for the reduction of methyl orange (MO) increased for catalysts (3), (1), and (2) and were 0.0332, 0.0347, and 0.0385 mg MO/mg catalyst/min, respectively. Thus, nickel nano-catalysts (1) and (2) provided the highest performance compared to the nano-catalysts for the reduction of PNP and MO, respectively. The first-order rate constant (min−1) of HGC-Ni (3), with respect to the reduction of PNP, was 0.173 min−1, while the first-order rate constant (min−1) for the reduction of MO by HGC-Ni (1) was 0.404 min−1. HGC-Ni (3) had the highest number of cycles with respect to PNP (17.9 cycles) and MO (22.8 cycles). The catalysts were regenerated efficiently. HGC-Ni exhibited remarkable electrochemical capacitance characteristics in the present study. This material achieved a notable specific capacitance value of 320.0 F/g when measured at a current density of 2 A/g. Furthermore, its resilience was highlighted by its ability to maintain approximately 86.8% of its initial capacitance after being subjected to 2500 charge and discharge cycles. This finding suggests that this HGC-Ni composite stands out not only for its high capacitive performance but also for its durability, making it an attractive and potentially economical choice for energy-storage solutions in various technological applications. [ABSTRACT FROM AUTHOR]

Manganese(II) complexes with phenanthroline derivatives modified with different substituents were synthesized and incorporated into Nafion layers covering the surfaces of glassy carbon electrodes and were studied electrochemically. Formal potentials and apparent diffusion coefficients were calculated and discussed. The suitability for electrocatalytic oxidation of ascorbic acid and glycolic acid was examined. The surfaces of modified electrodes were characterized using atomic force microscopy. [ABSTRACT FROM AUTHOR]

The aim to access linked tetravanadate [V4O12]4− anion with mixed copper(II) complexes, using α-amino acids and phenanthroline-derived ligands, resulted in the formation of four copper(II) complexes [Cu(dmb)(Gly)(OH2)]2[Cu(dmb)(Gly)]2[V4O12]·9H2O (1) [Cu(dmb)(Lys)]2[V4O12]·8H2O (2), [Cu(dmp)2][V4O12]·C2H5OH·11H2O (3), and [Cu(dmp)(Gly)Cl]·2H2O (4), where dmb = 4,4′-dimethioxy-2,2′-bipyridine; Gly = glycine; Lys = lysine; and dmp = 2,9-dimethyl-1,10-phenanthroline. The [V4O12]4− anion is functionalized with mixed copper(II) units in 1 and 2; while in 3, it acts as a counterion of two [Cu(dmp)]2+ units. Compound 4 crystallized as a unit that did not incorporate the vanadium cluster. All compounds present magnetic couplings arising from Cu⋯O/Cu⋯Cu bridges. Stability studies of water-soluble 3 and 4 by UV–Vis spectroscopy in cell culture medium confirmed the robustness of 3, while 4 appears to undergo ligand scrambling over time, resulting partially in the stable species [Cu(dmp)2]+ that was also identified by electrospray ionization mass spectrometry at m/z = 479. The in vitro cytotoxicity activity of 3 and 4 was determined in six cancer cell lines; the healthy cell line COS-7 was also included for comparative purposes. MCF-7 cells were more sensitive to compound 3 with an IC50 value of 12 ± 1.2 nmol. The tested compounds did not show lipid peroxidation in the TBARS assay, ruling out a mechanism of action via reactive oxygen species formation. Both compounds inhibited cell migration at 5 µM in wound-healing assays using MCF-7, PC-3, and SKLU-1 cell lines, opening a new window to study the anti-metastatic effect of mixed vanadium–copper(II) systems. [ABSTRACT FROM AUTHOR]