Raman spectra and simulation of cis‐ and trans‐cyclooctene for conformational analysis compared to inelastic neutron scattering

Abstract

Simulated and measured Raman spectra are used to determine the molecular conformation of trans-cyclooctene. This is the first reported Raman spectrum of this highly strained species. A crown structure results in a computed Raman spectrum, which is in good agreement with the experiment; a chair structure does not. Comparison is made with the case of cis-cyclooctene. The computed structure and limitations of the method of conformational analysis are discussed. In particular, the relative merits of Raman spectroscopy in comparison with infrared and inelastic neutron scattering (INS) are evaluated using computed spectra for all three methods and comparison of the observed INS for cis-cyclooctene with that computed for two conformations. It is concluded that the combination of computed and observed Raman spectra provides a useful method for conformational analysis for cases of this type.

Recent advances in linear and nonlinear Raman spectroscopy. Part V

“…[255] Simulated and measured Raman spectra were used by Kulterer and Hudson to determine the conformation of trans-cyclooctene. [256] This is the first reported Raman spectrum of this highly strained species. A crown structure resulted in a computed Raman spectrum, which is in good agreement with the experiment, whereas a chair structure was not.…”

“…The FT‐IR and FT‐Raman spectra of 2,5‐dihydroxybenzoic acid were recorded and interpreted in terms of various possible conformers using DFT at the B3LYP/6‐31G* level . Simulated and measured Raman spectra were used by Kulterer and Hudson to determine the conformation of trans ‐cyclooctene . This is the first reported Raman spectrum of this highly strained species.…”