Infrared and Raman spectra and molecular mechanics calculations of 4H-pyran and related molecules

Abstract

The infrared and Raman spectra of 4H-pyran have been analyzed and assigned in terms of C-2v symmetry. Molecular mechanics calculations (MM3) have been carried out for this molecule and also for 1,4-cyclohexadiene and 1,4-dioxin in order to compare the calculated vibrational frequencies with those observed. In most cases the MM3 calculations do a reasonable job of estimating the frequencies. Band type calculations were carried out to aid with the assignments.