14720-24-2Relevant articles and documents
Photolysis of argon matrices containing tribromoboron and dihydrogen: Synthesis of hydroboranes via dibromoboron
Moroz, Antoni,Sweany, Ray L.
, p. 5236 - 5242 (2008/10/08)
Ultraviolet irradiation (λ = 254 nm) of argon matrices containing BBr3 and high concentrations of H2 produces an intermediate, BBr2, which reacts with H2 to form HBBr2, H2BBr, and HBr. The intermediate is completely destroyed by irradiation at 680 nm, the position of a broad absorption band, producing the same hydrogenation products that form by using ultraviolet radiation. The reaction of BBr2 with HD gives HBr and DBBr2 1.6 times more readily than DBr and HBBr2. The spectrum of BBr2 has been reported earlier; herein we reassign the totally symmetric B-Br stretching mode to a weak band at 551.0 cm-1. There is no evidence that either BBr2 or BBr3 forms a ground-state complex with hydrogen in spite of the fact that BBr2 forms more readily in the presence of H2 and that it is readily converted into HBBr2 and H2BBr by H2. However, a complex of hydrogen and BBr2 in its first excited state may lead to the hydrogenation products. The yield of H2BBr is greatest when the concentration of hydrogen in the matrix is greater than about 10 mol %. Both hydrogen atoms that make up the H2BBr come from the same molecule of hydrogen. Mixtures of H2 and D2 give H2BBr and D2BBr with only a trace of HDBBr whereas matrices containing HD produce only HDBBr.
