Excitation profiles of soret-excited resonance raman spectra of platinum-hematoporphyrin complexes

Abstract Resonance Raman spectra of solid hematoporphyrin-IX [H 2 (Hem)] and a series of platinum-hematoporphyrin complexes, the diacid species [H 4 (Hem)]CL 2 and [H 4 (Hem)]PtCl 4 , and of cis -Pt(H 2 Hem)Cl 2 complexes have been studied. Several bands show intensity changes with excitation wavelengths in the strong Soret and the weak α and β absorption regions. The 4579 A excitation in the Soret region enhances mainly the totally symmetric modes, whereas excitation in the α and β absorption region enhances the non-totally symmetric modes. New absorption maxima at 4965 and 4658 A have been revealed from the excitation profiles which were not visible in the absorption spectra of the complexes and which confirm the assignment of the α band near 5190 A in the cis -Pt(H 2 Hem)Cl 2 and Pt(Hem) complexes.