Nature of the valence excited states of bromine in the T and P clathrate cages

Fidel A Batista-Romero; Antonio Gamboa-Suárez; Ramón Hernández-Lamoneda; Kenneth C Janda

doi:10.1063/1.4979909

Nature of the valence excited states of bromine in the T and P clathrate cages

J Chem Phys. 2017 Apr 14;146(14):144311. doi: 10.1063/1.4979909.

Authors

Fidel A Batista-Romero¹, Antonio Gamboa-Suárez¹, Ramón Hernández-Lamoneda¹, Kenneth C Janda²

Affiliations

¹ Centro de Investigaciones Químicas, IICBA, Universidad Autónoma del Estado de Morelos, Ave. Universidad 1001, Cuernavaca 62209 Morelos, Mexico.
² Department of Chemistry, University of California, Irvine, California 92697, USA.

PMID: 28411608
DOI: 10.1063/1.4979909

Abstract

The guest-host intermolecular potentials for the valence excited states of Br₂ in the tetrakaidecahedral(T) and pentakaidecahedral(P) clathrate cages have been calculated using ab initio local correlation methods. We find that the excited states are more strongly bound than the corresponding ground states even in the small T cage where bromine has a tight fit. The angular dependence of the interaction energies is quite anisotropic; this reflects in the corresponding electronic shifts where regions of maxima for blue-shifts in the T cage indicate the presence of halogen bonding. We predict a large temperature dependence of the electronic shifts and compare absolute values with recent experimental studies. This stringent test indicates the reliability of local correlation treatments to describe weak intermolecular forces in ground and excited states.