An investigation of the structures, vibrational spectra, and relative energetics of CH3COBrO3 isomers

The structures, vibrational spectra, and relative energetics of CH3COBrO3 i somers have been examined using the B3LYP method in conjunction with differ ent basis sets. The CH3COOBrO2 structural form is found to possess the lowe st energy with an estimated heat of formation of -38.2 kcal mol(-1), at 0 K , as determined from G2MP2 theory. The next lowest energy structural form i s CH3COOOOBr, which lies 7.7 kcal mol(-1) above CH3COOBrO2. The isomeric fo rms possessing higher energies are CH3COOOBrO and CH3COBrO3. We have examin ed the implication of the formation of CH3COBrO3 isomers from the atmospher ic cross-reactions of the acetylperoxy (CH3COO2) and bromine monoxide (BrO) radicals and determined the possible dissociation products of the most lik ely CH3COBrO3 isomers.