Mechanistic insight on the water exchange mechanism of [Zn(tren)H<inf>2</inf>O]²⁺ and related complexes from a DFT study

Abstract

The mechanisms for water exchange on [Zn(L)H2O]2+⋅H2O (L = tren: tris(2-aminoethyl)amine, trep: tris(2-phosphinoethyl)phosphine, and tres: tris(2-arsinoethyl)arsine) were studied using density functional theory (B3LYP/6-311 + G**) and evaluated by MP2 and B3LYP(PCM) energy calculations. The activation barriers for the water exchange reaction on [Zn(L)H2O]2+⋅H2O (L = tren, trep and tres) are (B3LYP/6-311 + G**) 9.9, 10.13 and 11.23 kcal mol−1, respectively. Topological analyses of the investigated ground state complexes were performed. The energy and structural data support an associative interchange (Ia) water exchange pathway.