Studies On The Nucleophilic Reactions Of 5-(4-nirophenyl)-10, 15,20-triphenylporphyrin

The porphyrins are a class of naturally occurring macrocyclic compounds, which play a very important role in the metabolism of living organisms. The introduction of functional groups into easily available, pre-made tetrapyrroles remains one of the pressing targets in porphyrin chemistry to further advance applications in biology, medicine, and materials science.In this dissertation, the synthesis and reactions of 5-(4-nirophenyl)-10,15,20-triphenylporphyrin and its metal complexes are studied. The main contents and conclusions are shown as follow:In.chapter 1, the advances in modern synthesis of porphyrins and chemical modification on porphyrin ring were reviewed. The synthesis of 5-(4-nirophenyl)-10,15,20-triphenyl-porphyrin(NO₂TPP) and reactions of NO2TPP and its metal complexes with different nucleophilic reagents were subjected to systemic investigation for developing the new synthetic method of porphyrins.In chapter 2, NO2TPP was prepared and the effects of conditions on reaction were studied. The highest yield of mono-nitrified product was obtained after 2h. With time running on, bi-nitrified product increased. The multi-nitrified product appeared after 6h. And the low temperature(-3⁰℃) was advantageous to yield of mono-nitrified product, the high temperature led to more bi-nitrified product. Complex oxidic products were obtained in room temperature.Substitution reactions of 5-(4-nitrophenyl)-10,15,20-triphenyl-porphyrin NO2TPP and its metal complexes with different nucleophilic reagents were studied for preparing asymmetric porphyrin. The reaction products are different with the nucleophilic reagents changing. 5-[4-nitro-3-(5,10,l5,20-tetraphenyl-porphyrinyl)]phenyl-10,l5,20-triphenylporphyrin, diporphyrin, was obtained when NO2TPP reacted with sodium phenoxide or diphenoxide in DMF solution. Whereas the nitro group was reduced and NH2TPPM(II) was achieved when the metal(Ni, Zn) complex of NO2TPP reacted with above nucleophilic reagents in the same condition. The reductive product was alsoachieved when NO2TPP reacted with mercaptoethanol or thiophenol and lithium hydroxide. While the nitro group was substituted by cyanic anion and CNTPP was achieved when NO2TPP reacted with sodium cyanide. The effects of conditions on production of diporphyrin P5 were studied. We found that good yield (63%) of diporphyrin P5 was obtained at 150℃ in DMF solution after 8h. We suggest that diporphyrin P5 is formed via a single electron transfer (SET) or anion free radical mechanism.In chapter 3, 5-(4-amino-phenyl)-10,15,20-triphenylporphyrin (NH2TPP) was prepared by reduction of NO2TPP with SnCl₂. A new Schiff base was synthesized by direct reaction of NH2TPP with 2,6-pyridinecarboxaldethyde and it was characterized with IR, UV, NMR and MS.