Microsolvation of heavy halides

Y. CHAMORRO; E. FLOREZ; A. F. MALDONADO; G. A. AUCAR; A. RESTREPO

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY

JOHN WILEY & SONS INC

Lugar: New York; Año: 2020

0020-7608

The fundamental question of how intermolecular interactions lead to the stabilization of heavy halides (Br − , I − , At − ) microsolvated with up to six explicit water molecules is addressed here. An exhaustive exploration of the Potential Energy Surfaces (PES) using a random search algorithm followed by optimization of molecular geometries using pseudopotentials and at the full four component relativistic levels of theory, affords a good number of structures with high probabilities of occurrence, highligthing the important role of local minima to reproduce experimentally measured properties. Sequential hydration enthalpies for astatide are reported here for the first time in the scientific literature. Closed shell (ionic, long range) as well as intermediate character interactions (contributions from closed shell and covalent) are at play stabilizing the clusters. The ability of water molecules to either donate or to accept electron density dictates the nature and strength of the corresponding hydrogen bonds in solvation shells. Binding energies and molecular geometries are shown to be more sensitive to electron correlationthan to relativistic effects.