Theoretical interpretation of infrared spectra of the ClH stretching vibration in the gaseous (Ch3)2O · · · HCl complex

The paper presents a theoretical interpretation of the fine structure of infrared spectra of the ClH stretching region in the gaseous (CH3)2O ··· HCl complex. The idea of Millen and Schrems is adopted, in which the spectrum represents a vibrational progression of the hydrogen‐bond stretching mode, and each subband is formed by the progression of the hydrogen‐bond bending mode. The rotational structure is present in such defined fine bands. Theoretical bands are calculated for three different temperatures and for the complex with DCl using two coupling parameters evaluated from the bandwidth. Results show that the most intense peak is associated with the Oσ ← Oσ transition in the stretching O ··· Cl vibration. They also suggest that the complex is nonplanar.