Comparative Analysis of Low-Resolution Microwave Spectra of Monobasic Alcohols

Additive modeling of low-resolution (LR) microwave spectra using high-resolution spectra was employed for calculating the frequencies of the LR spectra for trans- and gauche-conformations of ethanol (CH₃CH₂OH) and the trans-conformation of deuterolabeled 2propanol ((CD₃)₂CDOH) in the 0–2 THz range. The regions were found for the frequencies of the LR spectra, in which light absorption by these two molecules is greatest: 660–680 and 1120–1160 GHz for the gauche- and trans-conformation of ethanol and 480–500 GHz for the trans-conformation of deuterolabeled 2propanol. A comparative analysis was carried out for the spectral regions featuring maximum light absorption by ethanol, 1propanol, 2propanol, and deuterolabeled 2propanol. It was concluded that in going to heavier compounds, the LR spectral maxima are shifted toward lower frequencies. This shift is useful for the spectral identification of these molecules in environmental monitoring and production quality control.