Abstract
M.Sc.
[AuCl(PPh3)] was reacted with mixed thiols in the presence of silver(I) oxide, resulting in
complexes of the type [Au(SC6H4X)(PPh3)] X= Cl, NH2,CH2, forming silver chloride as
a by-product. In addition to the above series [Au(SCH2(C6H4)3(2-C6H5(C6H4N)] was
prepared via a different route, where [AuCl3(2-C6H5(C6H4N)] was reacted with benzyl
mercaptan under reflux in the presence of silver(I) oxide for 3 h, forming silver chloride
as a by-product. Palladium complex [PdCl2(2-C6H5(C6H4N)] was prepared by reacting
[PdCl2(MeCN)] with 2-phenylpyridine at room temperature for 2 h. All complexes were
characterized by 1H, 13C, 31P{H} NMR, IR, mass spectrometry and elemental analysis.
Characterization of the starting materials [AuCl3(2-C6H5(C6H4N)] and [PdCl2(2-
C6H5(6H4N)] by single crystal X-ray diffraction confirmed their chemical formula.
All complexes were reacted with sulfur dioxide (SO2) and the reactions were monitored
by electrochemistry and UV-vis spectroscopy. The electrochemical study of the
complexes, using cyclic voltammetry (CV) and Osteryoung square wave voltammetry
(OSWV), showed one anodic peak, which is due to gold(I/III) and an unresolved peak
due to thiolate ligand. Upon bubbling of SO2 to the complexes, there was an immediate
change of colour from clear to yellow, the CV results showing an increase in current of
the gold(I/III) peak. UV-vis spectroscopy studies showed a shift of peak form 250-286
nm, upon bubbling of SO2 to complexes.