Bound-Ion Pair X-Type Ligation of Cadmium and Zinc Dithiocarbamates on Cadmium Selenide Quantum Belts.

Wurtzite CdSe quantum belts with L-type n -octylamine, L-type ammonia, or Z-type Cd(oleate) 2 ligands are exchanged for several metal-dithiocarbamate ligands [M(S 2 CNR 1 R 2 ) 2 ]: Cd(S 2 CNPhMe) 2 , Cd(S 2 CNEt 2 ) 2 , Zn(S 2 CNPhMe) 2 , and Zn(S 2 CNEt 2 ) 2 . Successful ligand exchange with all M(S 2 CNR 1 R 2 ) 2 compounds occurs from {CdSe[Cd(oleate) 2 ] 0.19 } quantum belts (QBs), which induce similar spectral shifts in the absorption spectra of the ligand-exchanged QBs. Spectroscopic data, experimentally determined lattice strains, and ligand exchanges with [Na][Et 2 NCS 2 ] and [NH 4 ][MePhNCS 2 ] establish that the [M(S 2 CNR 1 R 2 ) 2 ] ligands bind as bound-ion-paired X-type ligands with (S 2 CNR 1 R 2 ) - groups ligated directly to the QB surfaces and [M(S 2 CNR 1 R 2 )] + groups serving as the charge-balancing ion-paired countercations. The X-type dithiocarbamate ligands do not impart any special electronic effects to the CdSe QBs.