The Reaction of BF3 with H2O Infrared Spectrum of BF2OH Trapped in Solid Neon

Published

October 1, 2000

Author(s)

Marilyn E. Jacox, Karl K. Irikura, Warren E. Thompson

Abstract

When a Ne:BF₃ sample is passed through a long stainless steel deposition line before being frozen onto a cryogenic observation surface maintained at approximately 5 K, the infrared spectrum of the resulting deposit includes prominent absorptions assigned to BF₂OH and weaker absorptions contributed by F₃¹¹B-OH₂. Pretreatment of the deposition line with isotopically substituted water leads to the appearance of absorptions of the ¹⁸O- and D-substituted products. The assignments are supported by the results of ab initio calculations at several different levels and by a least-squares force constant fit to the infrared absorptions of the isotopomers of BF₂OH. The thermochemistry of the reactions of BF₃ and H₂O to form F₃B-OH₂ and to form BF₂OH + HF has been calculated at the G2 level. Although the heats of reaction calculated for 298 K somewhat favor formation of the complex, when the entropy is also considered the two reactions become more competitive.

Citation

Journal of Chemical Physics

Volume

113

Issue

No. 14

Pub Type

Journals

Keywords

ab initio calculations, BF₂OH, entropy, H₂O-BF₃ complex, heats of reaction, infrared spectrum, neon matrix

Citation

Jacox, M. , Irikura, K. and Thompson, W. (2000), The Reaction of BF₃ with H₂O Infrared Spectrum of BF₂OH Trapped in Solid Neon, Journal of Chemical Physics (Accessed December 16, 2024)