Synthesis and crystal structure of bis(morpholino dithiocarbamato) Cd(II) complex and its use as precursor for CdS quantum dots using different capping agents
Cadmium(II) morpholine dithiocarbamate complex [Cd(morphdtc)2] was synthesized and characterized by single crystal X-ray crystallography. The molecular structure of the complex showed Cd(II) ion in a distorted 4 + 2 octahedral geometry, in which the two morpholine dithiocarbamates act as bidentate chelating and the central Cd ion bond the sulfur atoms of adjacent morpholine acting as bridging ligands to form centrosymmetric five coordinate dimeric molecules. The Cd(II) complex was thermolysed at 180°C to prepare CdS nanoparticles using three different capping agents. The pXRD patterns revealed a mixture of hexagonal and cubic crystalline phases of CdS nanocrystals. TEM images revealed semi-spherical and spherical nanoparticles, with the size range of 4.50–5.70 nm for OLM-CdS, 3.33–5.96 nm for HDA-CdS, and 3.00–5.83 nm for ODA-CdS. The particle size distribution of the CdS nanocrystallite is within the range 1.06 nm (SD ± 0.73) for OLM-CdS, 0.68 nm, (SD ±0.73) for HDA-CdS and 1.18 nm, (SD ± 0.60) for ODA-CdS. The lattice fringes showed that the particles are almost in the same environment with the interplanar of 0.32 nm for OLM-CdS, 0.34 nm for HDA-CdS, and 0.32 nm ODA-CdS. The band gaps energy were confirmed to be 1.59 eV for OLM-CdS, 1.65 eV for HDA-CdS, and 1.62 eV for ODA-CdS nanoparticles, respectively.
