Vibrational spectra and a potential function for 3-chlorocyclopropene and its various deuterated modifications

Abstract

I.r. and Raman spectra have been obtained for 3-chlorocyclopropene and 3-chlorocyclopropene-d3 under a variety of experimental conditions. For mixtures of the two d2 isotopic species and of the two d2 isotopic species, only infrared spectra have been recorded. The pattern of gas-to-condensed-phase frequency shifts is interpreted as evidence of hydrogen bonding for the CH hydrogen atoms. A complete assignment of the vibrational fundamentals for the d0 and d3 species is derived from the spectra. For the d0 species these frequencies (in cm−1) are: (a′) 3171, 3029, 1633, 1266, 1141, 913, 713, 591, 345; (a″) 3140, 1034, 1017, 866, 840, 349. With guidance from normal coordinate calculations 59 of the 60 fundamentals for the d1 and d2 species are assigned. The full set of 89 observed frequencies has been used to fit an 18-parameter valence-type potential function. In comparison with the force constants for CC and CC stretching of cyclopropene and 3,3-difluorocyclopropene, the CC force constants of 3-chlorocyclopropene show changes similar to those expected for a substitution of a single fluorine atom. This finding is consistent with a σ-acceptor role for the mechanism of the interaction of fluorine and chlorine atoms with the cyclopropene ring system.

Publisher

Elsevier BV

Publication Date

1-1-1987

Publication Title

Spectrochimica Acta Part A: Molecular Spectroscopy

Department

Chemistry and Biochemistry

Document Type

Article

DOI

https://dx.doi.org/10.1016/0584-8539(87)80062-4

Language

English

Format

text

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