Symmetrical and unsymmetrical nickel(II) complexes of N-(dialkylcarbamothioyl)-nitro substituted benzamide as single-source precursors for deposition of nickel sulfide nanostructured thin films by AACVD

摘要

The nickel(II) complexes of various N-(dialkylcarbamothioyl)-nitro substituted benzamides [dialkyl= di-propyl (2a); hexyl, methyl (2b); butyl, ethyl (2c); ethyl, isopropyl (2d)] have been synthesized and characterized by elemental analysis, I.R. spectroscopy, H-1 NMR and atmospheric pressure chemical ionization-mass spectrometry. The molecular structures of the complexes 2a and 2d were determined by single-crystal X-ray diffraction. Thermogravimetric analysis shows that complexes 2a-c decompose in a single step and complex 2d decomposes in two-steps to give a final residue corresponding to nickel sulfides. These complexes were used as single-source precursors for the deposition of nickel sulfide thin films by aerosol assisted chemical vapor deposition at 723 K. Powder X-ray diffraction patterns of the thin films deposited from complexes 2a and 2c showed the deposition of the hexagonal NiS phase with spherical crystallites. The films deposited from complex 2b showed hexagonal and rhombohedral systems of the millerite NiS phase. The degree of the surface roughness of the films was determined by atomic force microscopy. Scanning electron microscopy and energy dispersive X-ray analysis results showed a uniform distribution of nickel sulfide in the films, which makes them potentially useful semiconducting materials on a structured surface. (C) 2014 Elsevier Ltd. All rights reserved.