Gas-phase detection of the HBCC (X1Σ) molecule: a combined crossed beam and computational study of the B(2P)+C2H2(1Σg+) reaction

✍ Scribed by N. Balucani; O. Asvany; Y. T. Lee; R. I. Kaiser; N. Galland; M. T. Rayez; Y. Hannachi

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 186 KB
• Volume: 22
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.1094

✦ Synopsis

Abstract

A novel supersonic beam of ground‐state boron atoms [B(^2^P)] was employed to investigate the reaction of B(^2^P) with acetylene [C~2~H~2~(^1^Σ~g~^+^)] at an average collision energy of 16.3±0.4 kJ mol^−1^ at the most fundamental microscopic level. The crossed molecular beam technique was used to record time of flight spectra at mass to charge ratios of 36 (^11^BC~2~H^+^), 35 (^10^BC~2~H^+^/^11^BC~2~^+^), and 34 (^10^BC~2~^+^) at different laboratory angles. Forward‐convolution fitting of the laboratory data showed that only a product with the gross formula BC~2~H was formed via a boron versus hydrogen exchange. By combining experimental results with electronic structure calculations, the conclusion was that the reaction proceeded via the initial addition of B(^2^P) to the two carbon atoms of acetylene, leading to the formation of a first intermediate, the borirene radical (c‐BC~2~H~2~). This intermediate underwent various isomerization processes on the BC~2~H~2~ potential energy surface before decomposing into the linear HBCC(X^1^Σ) isomer via a hydrogen atom elimination. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1359–1365, 2001