Role of the uranyl oxo group as a hydrogen bond acceptor

Abstract

Density functional theory calculations have been used to evaluate the geometries and energetics of interactions between a number of uranyl complexes and hydrogen bond donor groups. The results reveal that although traditional hydrogen bond donors are repelled by the oxo group in the [UO 2(OH2)5]2+ species, they are attracted to the oxo groups in [UO2(OH2) 2(NO3)2]0, [UO2(NO 3)3]-, and [UO2Cl4] 2- species. Hydrogen bond strength depends on the equatorial ligation and can exceed 15 kcal mol-1. The results also reveal the existence of directionality at the uranyl oxo acceptor, with a weak preference for linear U=O-H angles. © 2011 American Chemical Society.