Ray L. Sweany Professor – Inorganic & Coordination Chemistry B.S., Michigan State University 1967 Ph.D., University of Illinois 1976 email: rsweany@uno.edu phone: (504) 280-6854 office: CBS 220

Research Interests A simple and well-studied as hydrogen is, its behavior has produced some surprises in recent history. With the possibility of increased reliance on hydrogen as an environmentally friendly fuel and its continued usefulness in catalysis, it will be important to understand hydrogen even more fully. Research here at UNO has focused on interactions of molecular hydrogen with metals over the years and more recently with acid and base sites of any sort. We have depended heavily on matrix isolation techniques. In the early eighties, we synthesized and characterized a series of organometallic complexes of molecular hydrogen wherein the hydrogen interacts as a pi-acid ligand. In these complexes, now well-known, the H-H bond is retained. We then undertook a series of experiments which attempted to show the separate acidity and basicity of hydrogen in interactions with simple Lewis acids and bases. It was easy to show hydrogen acting as an acid; the H-H stretching vibration becomes easily observed in such complexes. The position of the H-H stretching frequency tracks various measures of the base strength. It has been more difficult to observe hydrogen acting as a base. Partly this was due to our heavy dependence on argon matrices. Argon is fairly similar to hydrogen in its inherent base strength. Moreover, complexes of argon suffer smaller zero-point energy penalties than analogous hydrogen complexes.8 We found it necessary to switch to neon matrices in order to observe hydrogen interacting as a base.9 This latter work depended on observations with alkali halide ion-pairs. Most recently, we have turned our attention to interactions of hydrogen with zeolites. These experiments have made use of both Raman and infrared techniques.

Selected Publications "Interactions between Molecular Hydrogen and Alkali Halide Ion-Pairs in Neon Matrices" R. L. Sweany, L. Vuong and J. Bishara Journal of Physical Chemistry A 2002,106, 11440. "Interactions of Molecular Hydrogen with Alkali Halides in Argon Matrices: A Computational Model" M.. L. McKee and R. L. Sweany Journal of Physical Chemistry A 2000, 104, 962.