E. Manoj

Preparation, magnetic and EPR spectral studies of copper(II) complexes of an anticancer drug analogue

Ten new copper(II) complexes of five potential bisthiocarbohydrazone and biscarbohydrazone ligands were synthesized and physico-chemically characterized. The spectral and magnetic studies of compounds are consistent with the formation of asymmetric di-, tri- or tetranuclear copper(II) complexes of deprotonated forms of respective ligands. The variable temperature magnetic susceptibility measurements of all complexes show antiferromagnetic interactions between the Cu(II) centers, in agreement with very broad powder EPR spectra. However, frozen solution EPR spectral studies are found in contradiction with the solid-state magnetic studies and indicate that the complexes are not very stable in solutions; the possible fragmentations of complexes are found in agreement with MALDI MS results. The EPR spectral simulation of most of the compounds is in agreement with the presence of two uncoupled Cu(II) species in solution.

Salicylaldehyde 4,4'-(hexane-1,6-diyl)thiosemicarbazone.

The title compound, C14H19N3OS, is in the thioketo form, with the thione S and hydrazine N atoms cis with respect to each other so that the S atom is involved in inter- and intramolecular hydrogen bonds simultaneously. Intermolecular C-H...S and C-H...O hydrogen bonds result in one-dimensional polymeric chains of molecules along the a axis. A weak C-H...pi ring interaction binds the polymeric chains together.

[Di‐2‐pyridyl ketone N4,N4‐(butane‐1,4‐di­yl)­thio­semi­carbazonato‐κ3N,N′,S]­di­oxo­vanadium(V)

The

2-Hydroxyacetophenone 4-phenylthiosemicarbazone

V^{V}

Copper(II) complexes of N(4)-substituted thiosemicarbazones derived from pyridine-2-carbaldehyde: Crystal structure of a binuclear complex

atom in the title complex,

Structural and spectral studies of novel Co(III) complexes of N(4)-substituted thiosemicarbazones derived from pyridine-2-carbaldehyde

[V(C_{16}H_{16}N_{5}S)O_{2}]

Synthesis and spectral characterization of zinc(II) complexes of N(4)-substituted thiosemicarbazone derived from salicylaldehyde : Structural study of a novel -OH free Zn(II) complex

, is five-coordinate in a highly distorted square-pyramidal geometry, with the pyridyl N, the azomethine N and the thiolate S atoms of the di-2-pyridyl ketone

Structural and spectral studies of nickel(II) complexes with N(4),N(4)-(butane-1,4-diyl) thiosemicarbazones

N^{4},N^{4}

Self-assembled macrocyclic molecular squares of Ni(II) derived from carbohydrazones and thiocarbohydrazones : Structural and magnetic studies

-(butane-1,4-diyl)thiosemicarbazone ligand and one oxo ligand occupying the basal coordination positions, while the second oxo ligand occupies the apical position. The molecules are interconnected by weak intermolecular interactions, mainly of the C-H...O type, involving the apical oxo atom.

Syntheses and EPR spectral studies of manganese(II) complexes derived from pyridine-2-carbaldehyde based N(4)-substituted thiosemicarbazones: Crystal structure of one complex

The title compound, C 15 H 15 N 3 OS, exists in the thione form and adopts an E configuration about the hydrazine bond, which is in the Z form with respect to the thiocarbonyl bond. An O-H···N intramolecular hydrogen bond promotes planarity in part of the molecule.