Transient resonance Raman investigation of CHBr2 and CHBrCl radicals

Transient resonance Raman spectra of CHBr2 and CHBrCl radicals following ultraviolet photolysis of CHBr3 and CHBr2Cl, respectively, in methanol solution are reported. Most of the Raman intensity appears in the C–Br stretch and Br–C–Br bend or Cl–C–Br bend fundamentals accompanied by moderate intensity in their overtones and/or combination bands. The CH2Br radical was previously observed to have only one predominant Franck–Condon active mode (the C–Br stretch) with a strong overtone progression. The Franck–Condon region photodissociation dynamics of the CHBr2 and CHBrCl radicals appear to have more multidimensional character compared to halomethyl radicals like CH2Br.