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

Abstract

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 RCCR′ (R = Me, Et, ⁿPr or ^tBu, R′ = H; R = Me or Et, R′ = Me). The gaseous mixtures were heated at 70 °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 Me₃SiCCH gave a single volatile carbaborane product, 1-Me₃Si-1,2-C₂B₃H₆.