Microsolvation of Sr2+ , Ba2+: Structures, energies, bonding, and nuclear magnetic shieldings

ANGIE VELZAQUEZ; YULY CHAMORRO; A. F. MALDONADO; G. A. AUCAR; A. RESTREPO

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY

JOHN WILEY & SONS INC

Lugar: New York; Año: 2021 vol. 121

0020-7608

An exhaustive exploration using non?relativistic and four?component relativistic formalisms of the potential energy surfaces for the microsolvation of Sr2+, Ba2+ with up to n = 6 water molecules is presented in this work. A multitude of well defined local minima stabilized by cation...water and by water...water interactions are found.Cation...water contacts transcend the electrostatic interactions of simplistic ionic bonding. The formal charge causes a chaotropic effect in the structure of the solvent affecting water to water hydrogen bonds and inducing water dissociation and microsolvation of the resulting H+, OH- ions in extreme cases. Relativistic effects are close to 0.7% or smaller in geometries and electronic energies, but they are around 27% for shieldings of Ba 2+ clusters. The nuclei of the central cations are des-hielded (around 10% in going from n = 1 to n = 3) due to microsolvation.