Transferability of Urey-Bradley Force Constants. II. Carbonyl Halides and Related Molecules

Abstract

Urey‐Bradley force constants have been fitted to the observed vibrational frequencies of COF₂, COCl₂, and COBr₂ by the method described in the previous paper. These force constants have been used to calculate the frequencies of COClF, COBrF, and COBrCl. Normal coordinates and the potential energy distribution among the various Urey‐Bradley coordinates have also been calculated. It is found that, despite the fact that the carbonyl stretching frequencies fall over a range of 100 cm^—1, the carbonyl stretching force constant is essentially the same for all molecules in the carbonyl halide series.