Vibrational spectra and structure of methyl chloroformate and methyl chloroformate-d3

Abstract

The infrared spectra of methyl chloroformate and methyl chloroformate-d3 are reported in the liquid and solid phases in the region 4000–50 cm−1. The liquid phase Raman spectra of these compounds are also reported. It is found that the two compounds readily crystallize as oriented polycrystalline films when cooled in contact with cesium iodide windows. The polarized infrared spectra obtained with these films make possible an improved vibrational assignment for the light compound and a good first assignment for the deuterium-substituted analog. The results are most consistent with a planar cis structure and there is no indication of the existence of a second conformer. No clear cases of crystal splitting are observed.