A density functional study of the structures and energetics of CXBrO whereX = H, Cl, and Br

The geometries, vibrational spectra, and relative energetics of CXBrO have been examined using density functional theory. The results show interesting structural trends for the bromination of formaldehyde. The thermodynamical ly most stable species is found to be CClBrO, with an estimated heat of for mation of -38.2 kcal mol(-1) at 298 K. The least stable CXBrO species is CB r2O with a heat of formation of -25.8 kcal mol(-1) at 298 K. The heat of fo rmation of CBr2O is in excellent agreement with experiments which determine the value from third-law kinetic studies.