Resonance Raman and theoretical investigation of the photodissociation dynamics of benzamide in S3 state

J Chem Phys. 2008 Jun 14;128(22):224310. doi: 10.1063/1.2938373.

Abstract

Resonance Raman spectra were obtained for benzamide in methanol and acetonitrile solutions with excitation wavelengths in resonance with the S(3) state. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with the motions mainly along the benzene ring C[Double Bond]C stretch nu(9), the Ph-CO-NH(2) and ring benzene stretch nu(14), the CCH in plane bend nu(17), the Ph-CO-NH(2) stretch and NH(2) rock nu(19), the ring trigonal bend nu(23), and the ring deformation and Ph-CO-NH(2) stretch nu(29). A preliminary resonance Raman intensity analysis was done, and the results were compared to those previously reported for acetophenone to examine the substituent effect. Solvent effect on the short-time photodissociation dynamics of benzamide was also examined. A conical intersection point S(2)S(3) between S(3) and S(2) potential energy surfaces of benzamide was determined by using a complete active space self-consistent field theory computations. The structural differences and similarities between S(3)S(2) point and S(0) were examined, and the results were used to correlate to the Franck-Condon photodissociation dynamics of benzamide in S(3) state.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Acetophenones / chemistry
  • Benzamides / chemistry*
  • Electrons*
  • Photochemistry
  • Solvents / chemistry
  • Spectrum Analysis, Raman*
  • Vibration

Substances

  • Acetophenones
  • Benzamides
  • Solvents