Synthesis and characterization of thiosemicarbazone derivatives of methylbismuth(III) dichloride: generation of one dimensional micro-rods of bismuthinite from [MeBiCl2·n{(C6H4OH)CHNNHCSNH2}] by a solvothermal process

Abstract

Reactions of methylbismuth(III) dichloride with thiosemicarbazones (TSC) in 1:1 and 1:2 molar ratios in anhydrous methanol yield [MeBiCl2.n{RR’CNNHCSNH2}] [where, R=R’=CH3 and n=1 (1) or n=2 (2); R=C6H4OH, R’=H and n=1 (3) or n=2 (4); R=C5H4N, R’=CH3 and n=1 (5) or n=2 (6)]. These monomeric adducts have been characterized by elemental analyses, Fourier transform infrared, nuclear magnetic resonance [1H, 13C{1H}] and fast atom bombardment mass spectrometry. The ligand appears to bind bismuth through sulfur and azomethine nitrogen atoms rendering penta- and hepta- coordination geometries, in (1, 3 and 5) and (2, 4 and 6), respectively, in the solution state. Low temperature (143–145°C) solvothermal transformation of (3) or (4) in refluxing xylene yields nano-structured flowers of amorphous bismuthinite (Bi2S3). Prolonged (~10 h) sintering at 150°C of the powder obtained from (4) yielded one-dimensional micro/nanorods of orthorhombic Bi2S3. All the materials were characterized by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray analyses.