Observations on a Ne:BF3 = 400:1 mixture into which a trace of normal or isotopically enriched water had been introduced, codeposited at 4.3 K with a beam of neon atoms that had been excited in a microwave discharge, demonstrate that a pair of absorptions previously assigned to the two boron-isotopic species of BF3+ should be reassigned to a BF2 stretching fundamental of BF2OH+. The OH stretching fundamental of that product was identified for the first time. The degenerate BF3 stretching fundamental of BF3+ appears at an unusually high frequency, consistent with strong pseudo-Jahn-Teller interaction of that ground-state fundamental with the B 2E' electronic state, as predicted by theory. The recent availability of detailed ab initio and density functional calculations of the vibrational fundamentals of BF2- and BF3- facilitates assignment of the infrared absorptions of those two products.
Citation: Journal of Chemical Physics
Pub Type: Journals
BF2 anion, BF2 cation, BF2OH cation, BF3 cation, BF3 anion, infrared spectrum, neon matrix, pseudo-Jahn-Teller interaction