Stability and Spectroscopic Properties of Negative Ions

STABILITY AND SPECTROSCOPIC PROPERTIES OF NEGATIVE IONS By Swayamprabha Behera, M.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, at Virginia Commonwealth University Virginia Commonwealth University, 2011. Major Director: Dr. Purusottam Jena, Distinguished Professor, Department of Physics Negative ions play an important role in chemistry as building blocks of salts and oxidizing agents. Halogen atoms, due to their ability to attract electrons, readily form negative ions. Considerable interest exists in the design and synthesis of new negative ions called superhaogens whose electron affinities are much higher than those of halogen atoms. This thesis deals with the design of such species. Using density functional theory I have studied two classes of superhalogens. First one involves d transition metal (Sc, Y, La) atoms surrounded by Cl while the second one involves simple metals (Na, Mg, Al) surrounded by pseudohalogens such as CN. Geometry, electronic structure, and electron affinity of these species containing up to 5 ligands have been calculated. Studies reveal a fundamental difference between the interaction of transition and metal atoms with electronegative ligands. In addition, pseudohalogens can be used to synthesize a new class of superhalogens.