A CCSD(T) AND DFT INVESTIGATION OF M-BENZYNE AND 4-HYDROXY-M-BENZYNE

4(-)Hydroxy-m-benzyne (2a), which is interesting in connection with re search on enediyne antitumor drugs, has been identified by comparing t he measured infrared spectrum with vibrational spectra calculated at t he CCSD(T)/6-31G(d,p) and B3LYP/6-31G(d,p) levels of theory. Although the vibrational spectra of phenol and 2a are similar, there are severa l infrared bands that make an identification of 2a in the matrix at lo w temperatures possible. Molecule 2a possesses the structure of a sigm a-biradical. Its isomer bicyclo[3.1.0]hexatriene is not stable, which is parallel to the result obtained for the parent molecule m-benzyne ( 1). The biradical character of 2a is somewhat lower than that of 1.