Spectroscopy and Dynamics of Resonance Raman Scattering by Iodobenzene Excited in the B Continuum.

Resonance Raman scattering in iodobenzene is studied for excitation in the region 219–233 nm (B 1A1←X 1A1). There is a rich Raman spectrum containing strong fundamentals of ring‐based modes and the CI stretch. On resonance, overtones and combination bands of most modes are strongly enhanced. The modulation of the CI stretch activity as a function of wavelength is interpreted in terms of the initial dynamical evolution of the molecule in the excited state. A normal mode analysis is also made of the ground‐state planar modes of iodobenzene in order to correlate the observations with the resonance Raman spectra in benzene.