Resonance Raman intensity analysis of the excited state proton transfer dynamics of 2-nitrophenol in the charge-transfer band absorption

Abstract

Resonance Raman spectra were obtained for 2-nitrophenol in cyclohexane solution with excitation wavelengths in resonance with the charge-transfer (CT) proton transfer band absorption. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with motion along more than 15 normal modes: the nominal CCH bend+CC stretch 12 (1326 cm-1), the nominal CCC bend 23 (564 cm-1), the nominal CO stretch+NO stretch+CC stretch 14 (1250 cm-1), the nominal CCH bend+CC stretch+COH bend 15 (1190 cm-1); the nominal CCH bend+CC stretch 17 (1134 cm-1), the nominal CCC bend+CC stretch 22 (669 cm-1), the nominal CCN bend 27 (290 cm-1), the nominal N O2 bend+CC stretch 21 (820 cm-1), the nominal CCO bend+CNO bend 25 (428 cm-1), the nominal CC stretch 7 (1590 cm-1), the nominal NO stretch 8 (1538 cm-1), the nominal CCC bend+N O2 bend 20 (870 cm-1), the nominal CC stretch 6 (1617 cm-1), the nominal COH bend+CC stretch 11 (1382 cm-1), nominal CCH bend+CC stretch 9 (1472 cm-1). A preliminary resonance Raman intensity analysis was done and the results for 2-nitrophenol were compared to previously reported results for nitrobenzene, p -nitroaniline, and 2-hydroxyacetophenone. The authors briefly discuss the differences and similarities in the CT-band absorption excitation of 2-nitrophenol relative to those of nitrobenzene, p -nitroaniline, and 2-hydroxyacetophenone. © 2006 American Institute of Physics.