South African Journal of Science
On-line version ISSN 1996-7489
SHUMBULA, Poslet M.; MOLOTO, Makwena J.; TSHIKHUDO, Tshinyadzo R. and FERNANDES, Manuel. Dichloro(bis[diphenylthiourea])cadmium complex as a precursor for HDA-capped CdS nanoparticles and their solubility in water. S. Afr. j. sci. [online]. 2010, vol.106, n.7-8, pp. 1-7. ISSN 1996-7489.
A single-source precursor route has been explored by using the diphenylthiourea cadmium complex as the source of cadmium sulphide (CdS) nanoparticles. The reaction was carried out using hexadecylamine (HDA) as the solvent and stabilising agent for the particles. The phenylthiourea complex was synthesised and characterised by means of a combination of spectroscopic techniques, microanalysis and X-ray crystal structural analysis. The diphenylthiourea complex was thermolysed in HDA at 120 ºC for 1 h to produce CdS nanoparticles. The CdS nanoparticles prepared were made water-soluble via a ligand exchange reaction involving the use of pyridine to displace HDA. The pyridine was, in turn, replaced by glucose and glucuronic acid. The absorption and emission spectra showed the typical features of quantum confinement for the nanoparticles for both HDA-capped and glucose- or glucuronic acid-capped CdS nanoparticles. The change in the capping groups, from HDA to glucose and glucuronic acid, resulted in absorption and emission features that were almost similar, with only slight red-shifting and tailing.
Keywords : cadmium complex; crystal structure; diphenylthiourea; nanoparticles; water-soluble.