CONTROL OF SURFACE COVERAGE AND SOLUBILITY OF THIOPHENOLATE-CAPPED CDS NANOCRYSTALLITES

Thiophenolate-capped CdS nanocrystallites (phi-CdS, mean diameter 3.5 nm, hexagonal) were prepared and isolated as powders by reacting thiop henol in the presence of triethylamine (TEA) with CdS nanocrystallites prepared from Cd2+ and H2S in N,N-dimethylformamide (DMF). The covera ge of the capping thiophenolate on the surface of CdS nanocrystallites can be controlled by varying the concentration of TEA in the preparat ion solution. The dispersibility giving a clear DMF solution of CdS, i .e., the solubility of phi-CdS in DMF, is well correlated with the sur face coverage of thiophenolate, i.e., the solubility can be increased by increasing the coverage of thiophenolate. (C) 1998 Academic Press.