Resonance Raman spectroscopy and theoretical study on the photodissociation dynamics of formanilide in S 3 state

Resonance Raman spectra were obtained for formanilide (FA) in acetonitrile solution with 239.5‐ and 245.9‐nm excitation wavelengths in resonance with the S 3 state, and density functional theory (DFT) was used to elucidate the electronic transitions and resonance Raman spectra of FA. The spectra indicate that, in the Franck–Condon region, photodissociation dynamics has a multidimensional character with the motions mainly along the CO stretching υ 8 , the ring CC stretch υ 9 , the NH wag and ring CCH in‐plane bend υ 11 , the NH wag and ring CCH in‐plane bend υ 12 , ring CC stretch and ring CCH in‐plane bend υ 16 , the NH wag and ring CCH in‐plane bend υ 17 , the ring CCH in‐plane bend υ 18 , and the ring trigonal bend υ 24 . The excited‐state dynamics of the S 3 state is discussed, and the results are compared with those previously reported for benzamide (BA) to examine the N‐ or C‐terminal‐substituted aromatic effect of the peptide bond. Copyright © 2010 John Wiley & Sons, Ltd.