The nature of the lowest energy optical transition for the complexes (η 6-naphthalene)Cr(CO) 3 and (η 6- phenanthrene)Cr(CO) 3 in the solid state has been investigated by Raman spectroscopy using a range of different excitation wavelengths progressively approaching the resonant condition. Examination of the resonantly enhanced Raman modes confirms that the first absorption is attributed predominantly to a metal-to-arene charge transfer transition for both complexes. A notable difference in the photochemistry of the two complexes was observed. In the case of the phenanthrene complex, population of the lowest energy excited state leads to a photochemical process which resulted in the loss of the arene ligand and formation of Cr(CO) 6. © 2011 American Chemical Society.