摘要：

CdS colloids undergo complexation with diethyldithiocarbamate anions (Et2NCS2-) in two stages. Interaction of Et2NCS2- with CdS surface initially results in partial dissolution of CdS colloids, but a new absorption band in the visible λmax 610 nm) develops at high concentrations (>1 mM) of Et2NCS2-. The association constants for these two processes have been determined to be 1900 and 170 M-1, respectively. Surface modification with Et2NCS2- decreases the emission yield as well as the emission decay lifetime of colloidal CdS. Laser pulse excitation (355 nm) of CdS colloids in the presence of Et2NCS2- leads to the formation of Et2NCS2 radical, which has an absorption maximum at 620 nm. The quantum yield for this oxidation process has been found to be 0.2. Photoelectrochemically produced Et2NCS2 radical undergoes dimerization with a rate constant of 4.6 × 109 M-1 s-1 in acetonitrile solution.

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