Preparation, spectroscopic characterization and X-ray crystal and molecular structures of nickel(II), copper(II) and zinc(II) complexes of the Schiff base formed from isatin and S-methyldithiocarbazate (Hisa-sme)

Photocatalytic and electrocatalytic hydrogen production using nickel complexes supported by hemilabile and non-innocent ligands

Nickel complexes with non-innocent ligands generated by one-electron reduction of octahedral Schiff base nickel(ii) complexes with hemilabile ligands exhibited excellent catalytic activities of over 5000 TONs through a metal-ligand cooperation mechanism for hydrogen evolution from water under visible light irradiation.

Cu(ii) complexes with tridentate sulfur and selenium ligands: catecholase and hydrolysis activity

Two new copper(ii) mononuclear complexes (CSe and CS) were synthesized and characterized by the following techniques: X-ray crystallography, elemental analysis, IR, EPR and UV-vis spectroscopies, conductimetric analysis and mass spectrometry.

Synthesis and synergistic studies of isatin based mixed ligand complexes as potential antifungal therapeutic agents

Metal based drugs are important class of chemotherapeutic agents that have the potential to circumvent drug resistance. Increasing drug resistance, treatment failures and limited treatment options necessitates the development of new therapeutic drugs with different mechanisms of action. Towards this direction, we synthesized a series of isatin based mixed ligand complexes of [Cu(dbm)LClH₂O] (mlc1), [Co(dbm)LCl₂]^‒(mlc2) and [Ni(dbm)LClH₂O] (mlc3) and evaluated their antifungal activity alone and in combination with fluconazole (FLC) against seven different Candida albicans isolates. The insight mechanism of antifungal action was revealed by studying apoptosis via terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. The study revealed that all these compounds showed antifungal activity at varying concentrations with mlc3 as the most potent compound with minimum inhibitory concentration ranging from 0.5–8 μg/mL and minimum fungicidal concentration ranging from 4–16 μg/mL. Upon combination with FLC, most of the interactions were either synergistic (54 %) or additive (32 %) with no antagonistic combination against any of the tested isolate. The study on their mechanism of action revealed that these compounds show apoptotic effect on C. albicans at sub-inhibitory concentrations, suggesting that strategies to target this process may augment the current antifungal treatment modalities.

Highly dispersed Cu(ii), Co(ii) and Ni(ii) catalysts covalently immobilized on imine-modified silica for cyclohexane oxidation with hydrogen peroxide

This paper describes the synthesis of Cu(ii), Co(ii) and Ni(ii) catalysts immobilized on imine-functionalized silica gel through a 3-aminopropyltriethoxysilane linker.

Synthesis, spectrochemical characterisation and catalytic activity of transition metal complexes derived from Schiff base modified chitosan

Three novel quadridentate Schiff base complexes, [Cu(OIAC)Cl(2)], [Co(OIAC)Cl(2)] and [Ni(OIAC)Cl(2)] [OIAC, a Schiff base ligand: (([2-oxo-1H-indol-3-ylidene]amino)chitosan)] have been synthesized. The molecular structure of the complexes has been characterised by elemental analyses, magnetic measurements, molar conductance studies, vibrational (FT-IR), electronic (UV-Vis) and (1)H NMR spectroscopic techniques. Thermal properties of the complexes have been investigated with TG-DTG analyses. The surface morphological difference of ligand and the complexes has been explored with scanning electron microscopy. The crystallinity of the compounds was analysed by powder X-ray diffraction technique and it was found to be less for the Schiff base (OIAC) and the complexes as compared to the chitosan. The catalytic activities of the complexes have been studied in the oxidation of cyclohexane, using environmental friendly oxidant, hydrogen peroxide. Complex with rough surface has shown higher catalytic activity compared to the other complexes.

(1E,2E)-1,2-Bis(2,3,4-trimeth-oxy-benzyl-idene)hydrazine

The title compound, C(20)H(24)N(2)O(6), was obtained as an unexpected product by the reaction of hydrazinium dithio-carbazate with 2,3,4-trimeth-oxy-benzaldehyde in refluxing ethanol. The mol-ecule lies on a center of inversion. The crystal packing is stabilized by weak inter-molecular C-H⋯O inter-actions.

BenzylN′-benzhydrylidenehydrazinecarbodithioate

In the title mol­ecule, C₂₁H₁₈N₂S₂, the C=N—N angle of 117.6 (2)° is significantly smaller than the ideal value of 120° expected for sp²-hybridized N atoms. This is probably a consequence of repulsion between the nitro­gen lone pairs and the adjacent N atom, as suggested in Zheng, Qiu, Lin & Liu [Acta Cryst. (2006), E62, o1913–o1914]. The two neighbouring benzene rings form a dihedral angle of 75.95 (3)° with each other, while subtending dihedral angles of 84.18 (3) and 8.44 (2)° with the third ring in the structure.

Benzyl 3-[(E,E)-3-phenyl-prop-2-enyl-idene]dithio-carbazate

The title compound, C₁₇H₁₆N₂S₂, a dithio­carbazate derivative, adopts an EE configuration with respect to the C=C and C=N double bonds of the propenyl­idine group. The 3-phenyl­prop-2-enyl­idene and dithio­carbazate fragments lie essentially in the same plane, with a maximum deviation from that plane of 0.074 (2) Å, while the dihedral angle between the 3-phenyl­prop-2-enyl­idene and the benzyl group is 77.78 (7)°. In the crystal structure, mol­ecules are linked by an N—H⋯S hydrogen bond and a weak C—H⋯S inter­action involving the terminal thione S atom, forming dimers that are arranged into sheets parallel to the bc plane. The crystal structure is also stabilized by C—H⋯π inter­actions.

Bis[benzylN′-(3-phenylprop-2-enylidene)hydrazinecarbodithioato-κ2N′,S]zinc(II)

In the title Zn^II complex, [Zn(C₁₇H₁₅N₂S₂)₂], the Zn^II atom lies on a twofold rotation axis. It exists in a tetra­hedral geometry, chelated by two deprotonated Schiff base ligands. The dihedral angle between each ligand is 71.48 (8)°. Mol­ecules are connected by weak C—H⋯S inter­molecular inter­actions into chains along the c axis. The crystal structure is further stabilized by C—H⋯π inter­actions involving the phenyl ring of the 3-phenyl­prop-2-enyl­idene unit.

Bis[benzyl N'-(3-phenyl-prop-2-enyl-idene)hydrazinecarbodithio-ato-κN',S]copper(II)

The Cu^II atom of the title complex, [Cu(C₁₇H₁₅N₂S₂)₂], lies on a twofold rotation axis, and is in a distorted tetra­hedral geometry with the two bidentate N₂S₂ Schiff bases. In the crystal structure, the mol­ecules are inter­connected into chains along the c axis by weak C—H⋯S inter­molecular inter­actions. The crystal packing is further stabilized by C—H⋯π inter­actions.