Ligand-exchange processes on solvated zinc cations: Water exchange on [Zn(H_2O)_4(L)]~(2+)·2H_2O (L = Heterocyclic Ligand)

摘要

The water-exchange mechanisms of [Zn(H_2O)_4(L) ~(2+)·2H_2O (L=imidazole, pyrazole, 1, 2, 4-triazole, pyridine, 4-cyanopyridine, 4-aminopyridine, 2-azaphosphole, 2-azafuran, 2-azathiophene, and 2-azaselenophene) have been investigated by DFT calculations (RB3LYP/6-311 + G**). The results support limiting associative reaction pathways that involve the formation of six-coordinate intermediates [Zn(H_2O)_5(L)]~(2+)·H_2O. The basicity of the coordinated heterocyclic ligands shows a good correlation with the activation barriers, structural parameters, and stability of the transition and intermediate states.