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(S₂CNR₁R₂)₂]: Cd­(S₂CNPhMe)₂, Cd­(S₂CNEt₂)₂, Zn­(S₂CNPhMe)₂, and Zn­(S₂CNEt₂)₂. Successful ligand exchange with all M­(S₂CNR₁R₂)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]­[Et₂NCS₂] and [NH₄]­[MePhNCS₂] establish that the [M­(S₂CNR₁R₂)₂] ligands bind as bound-ion-paired X-type ligands with (S₂CNR₁R₂)⁻ groups ligated directly to the QB surfaces and [M­(S₂CNR₁R₂)]⁺ 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.