Interactions of the B3 cluster with H atoms and H2 molecules

Abstract

A b initio electronic structure calculations on several σ- and three-center bonded B3H and B3H2 structures that correlate with the ground and first excited states of B3 (plus H or H2 ) have been carried out using correlation-consistent polarized valence double-zeta basis sets and complete-active-space self-consistent-field treatments of electron correlation. Geometries, electronic energies, and local harmonic vibrational frequencies were determined for two locally stable structures of B3H and three stable and one metastable structures of B3H2 as well as for transition states connecting such structures. Reaction energies for several processes and a barrier for the B3+H2→B3H2 reaction have also been calculated. A picture of the B3 reactivity is given in terms of two coupled potential energy surfaces and their avoided crossings. The relevance of our findings to future experimental work and similarities with the chemistry of boranes and related reactive species are emphasized.