Synthesis and characterisation of zinc and cadmium thiosemicarbazones: potential precursors for nano sized metal oxides/sulphides.

We report the synthesis and characterisation of thiosemicarbazones of Zinc and Cadmium, general formula MCl₂.LH (1–8) {Where M = Zn or Cd; L = C₁₁H₁₇N₃S, C₁₁H₂₁N₃S}. They have been characterised by elemental analyses, FT-NMR (¹H, ¹³C), FT-IR and ESI-Mass spectral studies. Sol-gel transformations of two of the representative compounds (2 and 6) yielded ZnO (A) and CdO (B), respectively. Surprisingly, solvothermal transformation of both of these compounds yielded ZnS (C) and CdS (D) without using any suphonating agent. The XRD pattern of synthesised materials suggested crystalline or amorphous nature of the samples with the particle size ZnO (10 nm), CdO (14 nm), ZnS (12 nm) and CdS (28 nm). Surface morphologies were investigated by SEM images. Absorption spectra of the materials show the band gap 3.75 eV, 2.95 eV, 3.8 eV and 3.0 eV for ZnO, CdO, ZnS and CdS, respectively. [ABSTRACT FROM AUTHOR]