REACTION OF BORON ATOMS WITH ETHYLENE - AB-INITIO STUDY OF THE BORIRANE RADICAL

Ab initio self-consistent field theory, second-order Moller-Plesset pe rturbation theory, hybrid density functional theory (B3LYP), coupled c luster theory including single and double excitations and with non-ite rative inclusion of triple excitations calculations have been used to examine the structure, vibrational properties and bonding of the borir ane radical which has (2)A(1) electronic structure. This species is bo und by about 40 kcal/mol with respect to the B+C2H4 ground states. For a comparison, CCSD calculations have been performed on both the borir ane molecule and the Pi-complexes for which the electronic structure c orrelates with the ethylene and boron ground states. The B-2(2) Pi-com plex is bound by about 13 kcal/mol while the B-2(1) complex is weakly bound and the (2)A(1) complex is not bound at all with respect to B+C2 H4 Vibrational frequencies and infrared intensities have been calculat ed at different levels of theory for the borirane radical in order to help its experimental identification.