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The fixation of atmospheric CO2 into value‐added products is a promising methodology. A series of novel nickel(II) complexes of the type [Ni(L)(CH3CN)2](BPh4)21–5, where L=N,N‐bis(2‐pyridylmethyl)‐N′, N′‐dimethylpropane‐1,3‐diamine (L1), N,N‐dimethyl‐N′‐(2‐(pyridin‐2‐yl)ethyl)‐N′‐(pyridin‐2‐ylmethyl) propane‐1,3‐diamine (L2), N,N‐bis((4‐methoxy‐3,5‐dimethylpyridin‐2‐ylmethyl)‐N′,N′‐dimethylpropane‐1,3‐diamine (L3), N‐(2‐(dimethylamino) benzyl)‐N′,N′‐dimethyl‐N‐(pyridin‐2‐ylmethyl) propane‐1,3‐diamine (L4) and N,N‐bis(2‐(dimethylamino)benzyl)‐N′, N′‐dimethylpropane‐1,3‐diamine (L5) have been synthesized and characterized as the catalysts for the conversion of atmospheric CO2 into organic cyclic carbonates. The single‐crystal X‐ray structure of 2 was determined and exhibited distorted octahedral coordination geometry with cis‐α configuration. The complexes have been used as a catalyst for converting CO2 and epoxides into five‐membered cyclic carbonates under 1 atmospheric (atm) pressure at room temperature in the presence of Bu4NBr. The catalyst containing electron‐releasing −Me and ‐OMe groups afforded the maximum yield of cyclic carbonates, 34% (TON, 680) under 1 atm air. It was drastically enhanced to 89% (TON, 1780) under pure CO2 gas at 1 atm. It is the highest catalytic efficiency known for CO2 fixation using nickel‐based catalysts at room temperature and 1 atm pressure. The electronic and steric factors of the ligands strongly influence the catalytic efficiency. Furthermore, all the catalysts can convert a wide range of epoxides (ten examples) into corresponding cyclic carbonate with excellent selectivity (>99%) under this mild condition. [ABSTRACT FROM AUTHOR]

In this research, a joint theoretical and experimental investigation was performed on the structural and spectral data (FT‐IR, Laser‐Raman, NMR, and UV–vis) of N,N‐dimethyl‐2‐[(1E)‐({[(methylsulfanyl)methanethioyl]amino}imino)methyl]aniline molecule. The theoretical electronic structure analyses were fulfilled by the density functional theory at the B3LYP level with the 6‐311++G(d,p) basis set in the gas phase of the isolated compound at the ground state. The vibrational works were analyzed in terms of potential energy distribution analysis to make the assignments of fundamental vibrational frequencies and the assigned modes of the title compound were compared with the reported experimental vibrational data. Later, Hirshfeld surface analysis over crystalline structure of the title compound was made to define the possible inter‐molecular interactions. In addition, the HOMO (highest occupied molecular orbital), LUMO (lowest unoccupied molecular orbital), UV–vis, and molecular electrostatic potential analyses were done. The molecular docking investigation was done in order to analyze the presence of interactions between the title ligand compound and the receptor protein 2VN0. [ABSTRACT FROM AUTHOR]

Copper(I) complexes of the types [Cu(N–N)(PPh3)2]NO3 (LC41–LC44) and [Cu(N–N)(PPh3)(NO3)] (LC45) carrying 3‐substituted 1‐pyridine‐2‐ylimidazo[1,5‐a]pyridine (N–N) derivatives and triphenylphosphine (PPh3) ligands have been prepared. The synthesized copper(I)–phosphine complexes were fully characterized by NMR, IR, ESI‐MS and UV–visible spectroscopy as well as by cyclic voltammetry. Selected structures such as LC42, LC43 and LC45 were additionally analysed by single‐crystal X‐ray method, which show that copper(I) centre adopts a highly distorted tetrahedral geometry. The 1H and 13C NMR spectral data of the complexes throw light on the nature of metal–ligand bonding. They display dπ–π* metal‐to‐ligand charge transfer (MLCT) transition and show quasireversible CuI/CuII metal oxidation. Among the copper(I)–phosphine complexes, LC41–LC44 exhibit moderate cytotoxicity (IC50: 24 h, 67–74 μM; 48 h, 58–70 μM) against human lung epithelial adenocarcinoma A549 cells, whereas LC45 displays the best activity (IC50: 24 h, 42 μM; 48 h, 34 μM) for A549 cancer cell line, which is better than that of the commercial antitumor drug cisplatin. All the complexes also displayed excellent selectivity by being relatively inactive against the human lung epithelial L132 normal cell line with selectivity index (SI) values ranging from 3.4 to 7.4. The complexes block cell cycle progression of A549 cells in G0/G1 phase. FACSVerse analyses are suggestive of reactive oxygen species (ROS) generation and apoptotic cell death induced by the LC41, LC43 and LC45. The induction of apoptosis in A549 cells was shown by Annexin V with propidium iodide (PI) and 4′,6‐diamidino‐2‐phenylindole (DAPI) staining methods and established the ability of LC41, LC43 and LC45 to accumulate in the cell nuclei. [ABSTRACT FROM AUTHOR]

A series of iron(III) bis‐complexes of the type [FeL2]X 1‐4, X = OH− (1), Cl¯ (3), and FeCl4¯ (2, 4), where LH is a tridentate (N,N,S) ligands such as N′‐(1‐pyridin‐2‐ylethylidene)‐hydrazinecarbodithioic acid methyl ester (HL1), N′‐(phenylpyridin‐2‐ylmethylene)‐hydrazinecarbodithioic acid methyl ester (HL2), N′‐quinolin‐2‐ylmethylene‐hydrazinecarbodithioic acid methyl ester (HL3), or N′‐(1‐methyl‐1H‐imidazol‐2‐yl‐methylene)hydrazinecarbodithioic acid methyl ester (HL4) has been isolated in moderate to good yields and completely characterized by elemental analyses, conductivity studies, and infrared and UV‐visible spectral measurements. The single crystal X‐ray structures of 1, 2 and 4 revealed that two deprotonated tridentate (NNS) ligands are meridionally coordinated to constitute a distorted octahedral coordination geometry around iron(III). In acetonitrile solution, all the complexes show quasi‐reversible Fe(III)/Fe(II) redox behavior. The in vitro cytotoxicity of the ligands HL1–HL4 (IC50: HL1, 64.5; HL2, 51.0; HL3, 124.0; HL4, 45.0 μM at 24 h) and complexes 1–4 (IC50: 1, 84.5; 2, 40.0; 3, 168.5; 4, 50.5 μM at 24 h) towards A549 lung cancer cell lines are similar to cisplatin (69.0 μM), revealing that free ligands cause cancer cell death with potency higher than the corresponding iron(III) complexes. Also, both the ligands and the complexes cause cell death mainly through apoptotic mode, as revealed by the observation of a higher percentage of apoptotic cells in acridine orange (AO)/ ethidium bromide (EB), and Annexin V‐Cy3 stained cancer cells. [ABSTRACT FROM AUTHOR]

A base‐promoted one‐pot three‐component domino reaction of in situ generated pyridinium ylides with α‐oxoketene dithioacetals (AKDTAs) lead to synthesis of indolizine derivatives. In this one‐pot transformation, three new bonds and one new ring was efficiently formed in one sequence. The current method provides a simple, convenient route for the synthesis of biologically important indolizine derivatives without using any catalyst in good yield. The synthesized compound 4 g was confirmed by single crystal X‐ray analysis. Efficient synthesis of densely functionalized indolizines have been reported with moderate to good yield under mild reaction condition via one pot multi component reaction. The current method provides a simple, convenient route for the synthesis of biologically important indolizine derivatives without using any catalyst with good yield. The synthesis of indolizines was also achieved by another route with short time by using 1‐(1‐cyano‐2,2‐bis(methylthio)vinyl)pyridin‐1‐ium ylide. The synthesized compound 4 g was confirmed by single crystal X‐ray analysis. [ABSTRACT FROM AUTHOR]

New palladium(II) complexes, [Pd(PPh3)L] ( 2) and [Pd(AsPh3)L] ( 3), were synthesized using 4-hydroxybenzoic acid (3-ethoxy-2-hydroxybenzylidene)hydrazide ( 1) ligand (H2L), and characterized using various physicochemical techniques. The molecular structures of 2 and 3 were determined using single-crystal X-ray diffraction, which reveals a square planar geometry around the palladium(II) metal ion. In vitro DNA binding studies were conducted using UV-visible absorption spectroscopy, emission spectroscopy, cyclic voltammetry and viscosity measurements, which suggest that the metal complexes act as efficient DNA binders. The interaction of ligand H2L and complexes 2 and 3 with bovine serum albumin (BSA) was investigated using UV-visible and fluorescence spectroscopies. Absorption and emission spectral studies indicate that complexes 2 and 3 interact with BSA protein more strongly than the parent ligand. The free radical scavenging potential of all the synthesised compounds ( 1- 3) was also investigated under in vitro conditions. In addition, the in vitro cytotoxicity of the complexes to tumour cells lines (HeLa and MCF-7) was examined using the MTT assay method. [ABSTRACT FROM AUTHOR]

A novel technique based upon injection-charge extraction by linearly increasing voltage (i-CELIV) in a metal-insulator-semiconductor (MIS) diode structure is described for studying charge transport in organic semiconductors. The technique (MIS-CELIV) allows selective measurement of both electron and hole mobilities of organic solar cells with active layers thicknesses representative of operational devices. The method is used to study the model high efficiency bulk heterojunction combination poly[ N-9′′-heptadecanyl-2,7-carbazole- alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT) and [6,6]-phenyl C70-butyric acid methyl ester (PC70BM) at various blend ratios. The absence of bipolar transport in PCDTBT-and-PC70BM-only diodes is shown and strongly imbalanced carrier mobility is found in the most efficient 'optimized' blend ratios. The mobility measurements are correlated with overall device performance and it is found that balanced and high charge carrier mobility are not necessarily required for high efficiencies in thin film organic solar cells. [ABSTRACT FROM AUTHOR]