Resonance Raman study on distorted symmetry of porphyrin in nickel octaethyl porphyrin

摘要

The resonance Raman (RR) spectra of nickel octaethyl porphyrin, Ni(OEP), in CH_2Cl_2 (solvent) at different excitations such as 514.5, 488.0, 441.6 and 406.7 nm are recorded and analysed. The results of the theory of distortion-induced RR intensity is applied to the observed spectra to determine the excited electronic state symmetry of porphyrin in Ni(OEP). It is concluded that the porphyrin molecule (D_(4h) structure) attains a non-polar distorted structure of D_2 symmetry rather than S_4 symmetry in CH_2Cl_2 solution.