The possibility of prediction of the 0-THz spectra of nonassociated polar liquids

Dielectric response of thermal rotational swings (reorientations) performed by polar molecules of a liquid causes the appearance of broadband spectra of absorption and complex permittivity that extend up to the frequencies of the far IR spectrum. A simple method is proposed that enables one to estimate the form of these spectra by specifying several molecular constants. The theory is based on a molecular model of a rectangular potential well that describes librations of dipoles during their lifetime in the local equilibrium state. Capabilities of the method are illustrated by examples of strongly absorbing nonassociated liquids.