Prediction of strong O-H/M hydrogen bonding between water and square-planar Ir and Rh complexes

Abstract

Intermolecular OH/M interactions, between a water molecule and square-planar acac complexes ([M(acac)L-2]), with different types of L ligands (en, H2O, CO, CN-, and OH-) and different types of metal atoms (Ir(I), Rh(I), Pt(II), and Pd(II)) were studied by high level ab initio calculations. Among the studied neutral complexes, the [Pd(acac)(CN)(CO)] complex forms the weakest interaction, -0.62 kcal mol(-1), while the [Ir(acac)(en)] complex forms the strongest interaction, -9.83 kcal mol(-1), which is remarkably stronger than the conventional hydrogen bond between two water molecules (-4.84 kcal mol(-1)).