5,10,15-Triphenyl-20-{2-[ α -(adenine-9)acetylamino]}phenyl porphyrin (1),5,10,15-triphenyl-20-{2-[ α -(cytosine-1)acetyl~amino]}phenyl porphyrin (2),5,10,15-triphenyl-20-{4-[ α -(cytosine-1)ethoxy]} phenyl porphyrin (3) and their zinc complexes Zn-1,Zn-2 and Zn-3 have been prepared and characterized by 1H NMR spectra,elemental analyses,electronic absorption spectra and mass spectra (FAB). Intramolecular π-π interactions and intramolecular metal-π interaction for 1,2,Zn-1,and Zn-2 have been investigated by several methods. 1H NMR studies demonstrate that the porphyrin π-system in 1 and 2 is parallel to the adenine and the cytosine aromatic ring, respectively. The electronic absorption spectral properties of free porphyrin derivatives and their zinc complexes have been compared with those of H_2TPP and ZnTPP. The results show that the UV-vis spectra of 1 and 2 are the same as that of H_2TPP,whereas the spectra of their zinc complexes show 7 nm red shifts of the Soret bands compared to that of ZnTPP. The emission spectra of Zn-1 and Zn-2 are independent of excitation wavelength. From combination of the evidence of absorption and emission spectra it is suggested the existence of intramolecular metal-π interaction in Zn-1 and Zn-2. The results of conformational analysis agreed quite nicely with that of experiments,thus it was further to validate the experimental conclusions. Triphenyl-20- {2- [alpha - (adenine-9) acetylamino]} phenyl porphyrin (1), 5,10,15-triphenyl- 20- {2- [alpha] (2), 5,10,15-triphenyl-20- {4- [cytosine-1] ethoxy]} phenyl porphyrin (3) and their zinc complexes Zn-1, Zn -2 and Zn-3 have been prepared and characterized by 1H NMR spectra, elemental analyzes, electronic absorption spectra and mass spectra (FAB). Intramolecular π-π interactions and intramolecular metal-π interactions for 1,2, Zn-1, and 1H NMR studies demonstrate that the porphyrin π-system in 1 and 2 is parallel to the adenine and the cytosine aromatic ring, respectively. The electronic absorption spectral properties of free porphyrin derivatives and their zinc gene complexes The results show that the UV-vis spectra of 1 and 2 are the same as that of H 2TPP, whereas the spectra of their zinc complexes show 7 nm red shifts of the Soret ba nds compared to that of ZnTPP. The emission spectra of Zn-1 and Zn-2 are independent of the excitation wavelength. From combination of the evidence of absorption and emission spectra it is suggested the existence of intramolecular metal-π interaction in Zn-1 and Zn-2. The results of conformational analysis agreed quite nice with that of experiments, it was further to validate the experimental conclusions.