PHOTOLUMINESCENCE QUENCHING OF QUANTUM-CONFINED CADMIUM-SULFIDE CLUSTERS BY NORBORNADIENE DERIVATIVES

Influence of norbornadiene and its derivatives on the photoluminescenc e (PL) of quantum-confined cadmium sulfide clusters (Q-CdS) prepared i n reverse micelles was investigated. It was found that norbornadiene-2 ,3-dicarboxylic acid (3) and its monopotassium salt (4) quenched PL in tensity by 77% and 62%, respectively, whereas its dipotassium salt (5) , norbornadiene (1) and norbornadiene-2,3-dimethylcarboxylate (2) had no effect on PL intensity. The formation constants for adducts formed between defect sites at the surface of Q-CdS clusters and 3 or 4 were also determined. PL quenching effect was attributed to the presence of ionizable proton which is considered to be able to trap photogenerate d electrons and remove them from possible decay process. Measurements of the PL decay by single photon counting technique also supported the se steady-state observations.