Resonance Raman spectroscopic and density functional theory study of p-nitroacetophenone (PNAP)

Resonance Raman spectra of p-nitroacetophenone (PNAP) have been obtained in resonance with the charge-transfer (CT) band using 252.7, 266 and 273.9 nm in methanol solvent. The spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with motion mainly along the CO stretching ν8(1691 cm−1) and the benzene ring stretch ν10(1593 cm−1). Our results indicate that -NO2 is more photoactive than -COCH3. The isomerization process of PNAP takes place somewhere after the wave packet leaves the Franck-Condon region.