Synthesis and X-ray single crystal structure of a cadmium(II) acetophenone thiosemicarbazone complex and its use as a single-source precursor for the preparation of CdS nanocrystallites and thin films

Abstract

A cadmium(II) acetophenone thiosemicarbazone complex has been prepared and characterized by elemental analysis, infrared and nuclear magnetic resonance (1H and 13C{1H}) spectroscopic techniques. Its single crystal structure has also been determined. The compound is found to be monoclinic, space group C2/c, with a=12.1020(3)Å, b=11.7410(3)Å, c=19.4050(8)Å, β=109.903(1)° and Z=4. The coordination geometry around the cadmium atom was found to be tetrahedral with coordination from two sulfur atoms of neutral ligands and two iodine atoms. The complex was exploited as a single source precursor for the synthesis of CdS nanocrystallites using the solvothermal decomposition and pyrolysis method and for thin films using the aerosol assisted chemical vapor deposition technique. In the solvothermal process, aliquots of the reaction mixture were taken out after 30min, 1, 2 and 5h time intervals to study the time dependent size and morphology of the nanomaterials. The obtained nanomaterials and thin films were characterized by powder X-ray diffraction, transmission electron microscopy, energy dispersive X-ray analysis, selected area electron diffraction pattern, UV–Vis, Photoluminescence, IR and Raman spectroscopy. Peak broadening in the X-ray diffraction showed the presence of smaller size CdS nanocrystals. Transmission electron microscopy images showed the presence of spherical shaped CdS nanocrystallites. Selected area electron diffraction pattern supported formation of hexagonal CdS. Energy dispersive X-ray analysis showed a 1:1 stoichiometry of Cd and S. Morphological studies of thin films were carried out using scanning electron microscopy and atomic force microscopy techniques. The vibrational properties of CdS were studied by Raman spectroscopy.