Raman and Infrared Spectral Data, Assignments, Potential Constants, and Calculated Thermodynamic Properties for Oxalyl Chloride

Abstract

Raman displacements, semiquantitative relative intensities, quantitative depolarization factors (single-exposure method), and infrared wave numbers have been obtained for liquid oxalyl chloride (ClOC–COCl) at room temperature. A critical examination of the present and previous data has been made and probable values have been determined. Normal coordinate treatments have been made for both the cis- and trans-forms. A satisfactory assignment of the present and previous Raman and infrared bands has been made, assuming the sample to be in the trans-form. Only binary combinations and 1st overtones were used, except for the 2 highest bands at 3740 and 5140 cm−1. Fermi resonance occurs in 4 cases. Not more than 10 percent of the cis-form can be present, and the presence of even this much rests solely upon Saksena and Kagarise's reported temperature variation in the intensity of the 533-cm−1 Raman band, though the normal coordinate treatment does indicate that the strongest trans-Raman line at 620-cm−1 could occur near 533 for the cis-structure. The moderately polarized resonance triplet 450, 471, 488 can hardly be accounted for by the presence of a polarized fundamental in this region, for either the cis- or the trans-form. The heat content, free energy, entropy, and heat capacity were calculated (rigid rotator, harmonic oscillator approximation) for 11 temperatures from 100° to 1000°K for the ideal gaseous state at 1 atmos pressure.