Computational insights into structural and optical properties of P-containing and N-containing ligands capped CdSe clusters

The ligand effects on the structures and properties (energetics, binding energies, charge distribution and optical properties) of the (CdSe)n clusters (n = 3, 6, and 10) with P-containing (PH3, PH2Me, PHMe2 and PMe3) and N-containing (NH3, NH2Me, NHMe2 and NMe3) have been studied using density functional theory. The P atom and N atom in the ligands interact with Cd and form Cd–P and Cd–N bonds. The influence of P-containing ligands can be enhanced with increasing CH3 of ligands, while the N-containing ligands influence slightly change. A blueshift in absorption band was predicted for the clusters with increasing CH3 of P-containing ligands. We also found that the calculated binding energies for various ligands are found to decrease in the order PMe3 > NH2Me > NHMe2 > NH3 > NMe3 > PHMe2 > PH2Me > PH3. The use of hydrogen atom for modelling of the CdSe cluster passivating ligands is found to yield unphysical results as well.