Gas-phase flash reactions of diborane, triborane carbonyl and tetraborane with alkynes

摘要

Several known volatile closo-carboranes (1,5-C_2B_3H_5, 1,6-C_2B_4B_6, 2,4-C_2B_5H_7, 1,10-C_2B_8H_(10)) and their alkyl derivatives and ten new alkyl derivatives of these carboranes were identified from the thermal gas-phase flash reactions of B_2H_6, B_3H_7CO and B_4H_(10) with ethyne, propyne and but-2-yne. In addition, nido-C_4B_2H_6 and its methyl derivatives were obtained from B_2H_6-alkyne flash reactions. All carboranes found in these high-energy reactions are the most thermally stable isomers of their class. The non-isolable borane {B_3H_7} is suggested as the initiator in all thermal flash reactions reported here.