The Fourier Transform Raman Spectra of Zinc Protoporphyrin IX Dimethyl Ester and Its Axial Ligated Complexes, and Comparison with Their Resonance Raman Spectra

The Fourier Transform（FT） Raman spectra and resonance Raman spectra of Zinc Protoporphyrin Ⅸ dimethyl acter（ZnPP） and its ternary complexes with 2-, 3-aminopyridines, 2-, 3-picolines, pyridine, imidazole and benzimidazle are studied. Comparison of these spectra are discussed. Binding of an axial ligand results in the "core expansion" of porphyrin ring which is the cause of the decrease of the Raman skeletul mode ffequencies and the red shifts in the electronic absotption bands. The electron donating ability of the substituted pyridines and the steric effect of substituted imidezole have effects on the downshifts of Raman frequencies and red shifts of electronic absorption wavelengths.