Resonance Raman Intensities and Structure of S2 State of Nickel(II) Porphyrin by Time-Dependent Approach

Resonance Raman intensities and UV-visible absorption spectrum of nickel(II) porphyrin (NiP) were analyzed with time-dependent formulas under standard approximations for Condon mechanism of enhancement. The resultant dimensionless displacements on S2 state are comparable with those obtained by Spiro et al. from Kramers-Kronig transform methods. It was deduced from the calculations that there are large dimensionless displacements on the excited state along ν8 and ν2 coordinates. These normal modes consist of relatively large components of CβCβ, Cα Cm bond stretching and CαCmCα bond bending motions. Compared with the ground state, the average bond-lengths of　CβCβ, CαCm, and CαN bonds at S2 state increase respectively by 0.27, 0.14, and 0.07pm，while that of CαCβ bond decreases by 0.20pm，which are well in coincident with the SPMO calculations in literature.