Stability and chemistry of boron containing cations, anions, and neutrals

The structure, thermochemistry, isomerization and dissociation of the CH2BH2 and CH3BH radicals, cations and anions have been explored with a wide range of ab initio levels of computational theory and their formation has been probed by tandem mass spectrometry and RRKM kinetic theory. Calculations predict that CH2B H2&ceilr0;+ is not an equilibrium structure on the potential energy surface. The CH3B H&ceilr0;+ was characterized by its collision-induced dissociation mass spectrum and neutralization-reionization (NR) mass spectrometry was used to generate the CH3B H&ceilr0;• radical. While both CH2B H2&ceilr0;• and CH3B H&ceilr0;• are stable with respect to isomerization and dissociation, a relatively low barrier to the 1,2-hydrogen shift means that pure CH3B H&ceilr0;• can only be made cold, and so the above NR experiment likely produces a mixture of neutrals, of which only CH3B H&ceilr0;• can be reionized. Vertical electron attachment to CH3B H&ceilr0;• is endothermic which means the CH3B H&ceilr0;- anion is unlikely to be made from the cation or radical. In addition, the anion lies in a shallow well of only 48 kJ mol-1 and will undergo fast isomerization to CH2B H2&ceilr0;- below the dissociation limit. The B(N(CH3)2)3 radical cation and dication structures and dissociation products have been investigated by high level ab initio calculations and experimentally characterized by tandem mass spectrometry. The KER was measured for the metastable dissociation products of the B(N(CH 3)2)3 dication. There were four observed dissociation channels, two involving neutral losses and two involving charge separations. The neutral loss channels successfully compete with the charge separations, the dominant process actually being neutral loss of H2. The KER for the four metastable dissociations were determined to be T0.5(141++) = 368 +/- 18 meV, T0.5(127++) = 144 +/- 12 meV, Th (99+) = 2365 +/- 156 meV, Th(44+) = 2046 +/- 279 meV, and Th(128+) = 1942 +/- 332 meV