Ab initio characterization of the structure, vibrational, and energetic properties of Br-center dot HOCl, Cl-center dot HOBr, and Br-center dot HOBr anionic complexes

Ab initio molecular orbital methods have been employed to determine molecul ar structure, vibrational frequencies, and relative energetics of Br-. HOCl , Cl-. HOBr, and Br-. HOBr anionic complexes. These parameters were determi ned using second-order Moller-Plesset perturbation theory (MP2) and coupled cluster methods. The minimum energy structures for all three complexes are reported. The minima for the mixed halogen conformers place the halogen an ion in complexation through the hydrogen. The calculated binding energies a re 23.3, 19.5, and 19.5 kcal mol(-1) for Cl-. HOBr, Br-. HOCl, and Br-. HOB r, respectively.