The Reactions of Elemental Mercury with Reactive Halogens

Washington State University, Pullman WA

Investigators

Abstract

Kirk Peterson of Washington State University is supported by the Theoretical and Computational Chemistry Program to carry out theoretical investigations of the reactions of atomic mercury with reactive halogen species (X, HX, XO and X2 where X= chlorine, bromine, and iodine). High accuracy, large-scale potential energy surfaces for both ground and low-lying electronically excited states will be constructed using accurate ab initio electronic structure methods, i.e. multireference configuration interaction and coupled cluster methods with large one-particle basis sets. These results will be used to elucidate the thermochemistry, spectroscopy, and reaction dynamics of the relevant species involved. In calculations of potential energy surfaces, particular emphasis will be given to an accurate recovery of both scalar relativistic and spin-orbit effects. Given the lack of available information on nearly all of the systems, this project has the potential to impact significantly the knowledge of gas-phase mercury chemistry with reactive halogen species. Because of its high biological toxicity and long atmospheric residence time, mercury is considered to be a high priority among environmental pollutants. Recently, the contamination of the Arctic ecosystem by mercury has been of particular concern. In the atmosphere, mercury exists almost exclusively in the gas phase and in its elemental form, but the amount of data on its chemical reactions in the gas phase is surprisingly scarce. The outcomes of this project are expected to provide information that will improve the understanding of environmentally significant chemical reactions including mercury.