Quenching of triplet vinylidene radicals by helium

• Published in: Chemical physics letters Vol. 94; no. 2; pp. 240 - 242
• Main Author: Laufer, Allan H.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1983
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/0009-2614(83)87583-6

Triplet vinylidene radicals, produced in the vacuum-ultraviolet photolysis of acetylene, are observed in absorption at 137.4 nm. The lifetime in the presence of helium, for both the protonated and deuterated species, has been determined. Expressed as a bimolecular rate constant the values are k He H = (1.3 ± 0.3) × 10 −14 cm 3 molecule −1 s −1 and k He D = (2.4 ± 0.4 × 10 −15 cm 3 molecule −1 s −1. An upper limit for removal by acetylene has been deduced.