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Updated: Jul 13, 2026

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
Infrared spectra of ClCN+, ClNC+, and BrCN+ trapped in solid neon
Marilyn E Jacox1, Warren E Thompson
1Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8441, USA.
Abstract:
When a mixture of ClCN or BrCN with a large excess of neon is codeposited at 4.3 K with a beam of neon atoms that have been excited in a microwave discharge, the infrared spectrum of the resulting solid includes prominent absorptions of the uncharged isocyanide, ClNC or BrNC, and of the corresponding cation, ClCN+ or BrCN+. The NC-stretching fundamentals of the isocyanides trapped in solid neon lie close to the positions for their previously reported argon-matrix counterparts. The CN-stretching absorptions of ClCN+ and BrCN+ and the CCl-stretching absorption of ClCN+ appear very close to the gas-phase band centers. Absorptions of two overtones and one combination band of ClCN+ are identified. Reversible photoisomerization of ClCN+ to ClNC+ occurs. The two stretching vibrational fundamentals and several infrared and near infrared absorptions associated with electronic transitions of ClNC+ are observed. Minor infrared peaks are attributed to the vibrational fundamental absorptions of the CX and CX(+) species (X=Cl,Br).
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