74 research outputs found

    Perovskite CsPbBr3 Solar Cells With Novel Hole-Transporting Layer of Metal Complexes

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    For the first time, the novel application of Schiff-base copper complexes in all-inorganic perovskite CsBrBr3 solar cells has been explored and turns out they could be utilized as effective hole-transporting materials. Schiff-base copper complexes with halogen ligands (R=Cl and Br) are synthesized with an ease approach at a low cost, both of which exhibit decent power conversion efficiency of 4.55% and 5.71%, respectively, when being constructed into solar devices as hole transport layers. Thanks to high thermal/chemical stability of those Schiff-base metal complexes, the strengthened stability was achieved which is comparable to that of carbon-based CsBrBr3 solar cells. Although the power conversion efficiency is not as competitive as expected, the great potential exists for further optimizing the functionality of perovskite solar devices by finely tuning the photovoltaic properties of those Schiff-base metal complexes through coordinating ligands or replacing with other transition metals

    Spectroscopic characterization of schiff base-copper complexes immobilized in smectite clays

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    Herein, the immobilization of some Schiff base-copper(II) complexes in smectite clays is described as a strategy for the heterogenization of homogeneous catalysts. The obtained materials were characterized by spectroscopic techniques, mostly UV/Vis, EPR, XANES and luminescence spectroscopy. SWy-2 and synthetic Laponite clays were used for the immobilization of two different complexes that have previously shown catalytic activity in the dismutation of superoxide radicals, and disproportionation of hydrogen peroxide. The obtained results indicated the occurrence of an intriguing intramolecular redox process involving copper and the imine ligand at the surface of the clays. These studies are supported by computational calculations

    Highly ordered Nanomaterial Functionalized Copper Schiff Base Framework: Synthesis, Characterization, and Hydrogen Peroxide Decomposition Performance

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    An immobilized copper Schiff base tridentate complex was prepared in three steps from SBA-15 supports. The immobilized copper nanocatalyst (heterogeneous catalyst) was characterized by Fourier transform infrared spectroscopy (FT-IR), cross polarization magic angle spinning (CP-MAS), 13-carbon nuclear magnetic resonance (13C-NMR), atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA), and N2-physisorption. Moreover, morphological and structural features of the immobilized nanocatalyst were analyzed using transmission electron microscopy (TEM) and X-ray powder diffraction spectrometry (PXRD). After characterizing the nanocatalyst, the catalytic activity was determined in hydrogen peroxide (H2O2) decomposition. The high decomposition yield of H2O2 was obtained for low-loaded copper content materials at pH 7 and at room temperature. Furthermore, the nanocatalyst exhibited high activity and stability under the investigated conditions, and could be recovered and reused for at least five consecutive times without any significant loss in activity. No copper leaching was detected during the reaction by AAS measurements

    Studies of proteasome inhibition and apoptosis induction in triple‐negative breast cancer cells by novel amino acid–polypyridine–copper complex

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    An innovative ternary copper(II) complex, [Cu(Cl‐PIP)(Tyr)Cl]n, has been synthesized and characterized using infrared spectroscopy, elemental analysis and single‐crystal X‐ray diffraction analysis. X‐ray crystallography indicates that the Cu atom is five‐coordinated in a square‐pyramidal configuration. The unit forms a one‐dimensional chain along the crystallographic c‐axis. The complex was screened for cytotoxicity against a panel of eight human cancer cell lines, namely MDA‐MB‐231, CAL‐51, K562, HeLa, SGC‐7901, A549, MCF‐7 and SMMC‐7721. The best anticancer activity was obtained with triple‐negative breast cancer CAL‐51 and MDA‐MB‐231 cell lines, with IC50 values in the range 0.035–0.10 ÎŒM, and this was better than using carboplatin. The complex inhibits proteasomal chymotrypsin‐like activity, and docking studies reveal its interaction with 20S proteasome. In addition, the complex causes accumulation of ubiquitinated proteins, induces apoptosis and inhibits cell proliferation, indicating its great potential as a novel therapy for triple‐negative breast cancer

    Mechanism and Cyclic Voltammetry of Cu(en)2X2.nH2O Complexes in Some Nonaqueous Solvents

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    The electrochemical studies of solid 2.0 X 10-3M Cu(en)2X2.nH2O (n=0 for X=ClO4-, NO3-, SCN-, and n=1for Br-) in dimethylsulfoxide, acetonitrile  ,  and dimetylformamide /0.1M tetrabuthylammonium perchlorate , have been carried out by cyclic  voltammetry. The electrode process shows two electro reduction and two chemical steps(CECE) mechanism. The reduction potentials of Cu(en)2(ClO4)2 shift in the order DMF?  DMSO ?   AN contrary to one’s expectation.  For Cu(en)2(NO3)2 and Cu(en)2(SCN)2, the reduction potentials are more negative in DMSO relative to DMF as expected.  In DMF, the reduction potentials Epc1 shift anodically in the order: Cu(en)2(ClO4)2 ?  Cu(en)2(NO3)2 ?    Cu(en)2(SCN)2 indicating that Epc1 is also dependent on the nature of the anion, X Keywords: Cu(en)2X2.nH2O, Nonaqueous Solvent, Voltammogram, CECE mechanism, Reduction potentia

    Anti-Cancer Activity and Mutagenic Potential of Novel Copper (II) Quinolinone Schiff Base Complexes in Hepatocarinoma Cells

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    This study determined the cytotoxic, cyto-selective and mutagenic potential of novel quinolinone Schiff base ligands and their corresponding copper(II) complexes in human-derived hepatic carcinoma cells (Hep-G2) and non-malignant human-derived hepatic cells (Chang). Results indicated that complexation of quinolinone Schiff bases with copper served to significantly enhance cytotoxicity. Here, the complex of (7E)-7-(3-ethoxy-2-hydroxybenzylideamino)-4-methylquinolin-2(1H)-one (TV117-FM) exhibited the lowest IC50 value (17.9 ÎŒM) following 96 h continuous exposure, which was comparable to cisplatin (15.0 ÎŒM). However, results revealed that TV117-FM lacked cytoselectivity over non-malignant cells. Additionally, the complex was minimally effluxed from cells via Pglycoprotein (P-gp) and was shown to be non-mutagenic in the Standard Ames test. Furthermore, BrdU incorporation assays showed that it was capable of inhibiting DNA synthesis in a concentrationand time-dependent manner. However, inhibition was not as a consequence of DNA intercalation, as illustrated in electrophoretic mobility shift assays. Interestingly, it was shown that the ligand was capable of inhibiting the action of topoisomerase II, but this was lost following complexation. This indicated that the mechanism of action of the novel copper(II) complex was different from that of the parent ligand and suggests that TV117-FM may have a therapeutic role to play in the treatment of hepatocellular carcinoma. Studies are currently underway to elucidate the exact in vitro mechanism of action of this novel, metal-based anti-cancer agent

    Stability of Vanadium Chalcone Complexes

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    The vanadyl(IV) complexes of substituted chalcones were prepared by refluxing vanadyl sulphate with different substituted chalcones in ethanoic medium. The chalcones were prepared with different aromatic aldehydes like benzaldehyde, hydroxy benzaldehyde, nitro benzaldehyde and chloro benzaldehyde. The synthesized Vanadium complexes were characterized by different spectral techniques. The IR spectral studies revealed that the chalcone derivatives are bidentate ligand. Magnetic studies, electron spin resonance and UV studies suggest that the complexes are in square pyramidal geometry. Conductance measurements suggest that all complexes are non-electrolyte in DMF. The thermal study explained the stability of complex and its decomposition. The synthesized ligand and metal complexes were screened for their antibacterial activity against E. coli and Staphylococcus aureus bacterial strains and for antifungal activity against P. notatum

    Preparation and Electronic Property Investigation of Zinc(II)-Schiff Base Complexes in the Confined Space

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