Quenched gas-phase reactions of tetraborane(10), B4H10, with substituted alkynes: new nido-dicarbapentaboranes and arachno-monocarbapentaboranes

摘要

New alkyl derivatives of the nido-dicarbapentaborane, 1,2-C2B3H7, and arachno-carbapentaborane, 1-CB4H10, have been identified as the main volatile carbaborane products in quenched gas-phase reactions of tetraborane(10), B4H10, with alkyl-substituted ethynes RC CR' (R = Me, Et, Pr-n or Bu-t, R' = H; R = Me or Et, R' = Me). The gaseous mixtures were heated at 70 degrees C, and monitored by gas-phase mass spectrometry. Each reaction was quenched when the ethyne was used up. The quenched gas-phase reaction of B4H10 and Me3SiC CH gave a single volatile carbaborane product. 1-Me3Si-1,2-C2B3H6.