Sythesis And Properties Of The Porphyrin-nicacid Binary Compounds

Porphyrins have distinctive structures and predominant physical, chemical, optical properties, and have an important theoretical significance and potential applications values in biological science, biochemistry and medical chemistry. Now, more and more attention has been paid to the porphyrin, especially to the binary, ternary and multiple porphyrins linked with some bioactive substances. On the basis of careful study of the most recent documents, it has been found that the synthesis and properties of the porphyrin linked with nicacid are worth studying in depth. It's possible to realize the dual activity of porphyrin and nicacid. In this thesis, a series of novel porphyrin-nicacid binary compounds have been designed and synthesized. Then their properties of redox, fluorescence and semi-conductor have been studied in detail.Under the guidance of the above ideas, we have designed and synthesized a series of novel porphyrin-nicacid binary compounds and their metalloporphyrins with different chain length or substituents, studied their properties of redox, fluorescence and semi-conductor, and analyzed the effects of chain length and substituents on their properties. All these studies provide useful information for the reseach of their bioactivities, and have done full preparatory work for drug screening. Our work includes the following aspects:1. Ten porphyrin-nicacid binary compounds with different chain length or substituents were synthesized. 24 transition-metal complexes were also synthesized. All of them have been characterized, assigned and analyzed by EA, MS, UV-Vis, IR and 1H NMR. Finally, we simulated the stable conformation of the free-base porphyrin, and calculated the total energy of the compunds and the energy gay of the molecular orbitals. 2. Their of electrochemical, photochemical and photophysical properties have been analyzed by cyclic voltammetry, raman spectra, fluorescence spectra SPS and FISPS. The effects of chain length and substituents on their properties also have been studied.(1) Electrochemical properties: there are four redox couples of the free-base porphyrin responding to four redox reactions of the macroring. The electron-donor group (CH3O) makes the porphyrin ring easy to oxidant, and the electron-attracting group (Cl) makes it easy to reduce. Different chain length has little influence on the redox property of the porphyrin. The complexes are easier to reduce than the free-base porphyrin.(2) Fluorescence emission spectra: The electron-donor group(CH3O) makes the intensity of fluorescence emission spectra and the quantum field increase, however, the electron-attracting group (Cl) makes it in reverse. The quantum field of NBPTPPZn is the greatest one, and NBPTPPZn is easier to form closed comfomation than the others.(3) Raman spectra: The band at l572-1599cm-1, 1018-1031 cm-1, 999-1007 cm-1 and 869-888cm-1 are the characteristic band of the phenyl on the tetraphenylporphyrin. the band at 1541-1568 cm-1, 1489-1508 cm-1, 1228-1240 cm-1,l065-1088 cm-1 are the skeleton vibration of porphyrin, its order of the wave number is Ni2+>Co2+>Cu2+>Zn2+. The substituent has little influence on the the skeleton vibration of porphyrin, and has much influence on the vibration of phenyl. In addition, the chain length has little influence on the raman spectra of the porphyrin.(4) The surface photovoltage property: By SPS and FISPS, the photophysical properties of porphyrins were studied. The results show that porphyrins are p-type semiconductor. The band of SPS represents the transition ofπ→π*. The SPS of all the free-base porphyrins and their complexes are similar with their corresponding UV-Vis spectrum. 3. In addition, with the development of the porphyrin, porphyrin oligomers have attracted more and more attention. They have incomparable superiority in some respects, such as simulation of the photochemical center in photosynthesis, organic solar cell, molecular switch, organic electroluminescence, optical storage materials, etc. To this day, the synthesis and the studies on the photochemical and photophysical properties of the porphyrin dimer is an attracting and challenging field yet. We designed and synthesized a succinyloxyl-bridged meso-tetraphenylporphyrin dimer and its six transition-metal complexes.All of them have been characterized, assigned and analyzed by EA, MS, UV-Vis, IR and 1H NMR. The stable conformation of the dimer is"face to face"closed one. The electrochemical, photochemical and photophysical properties are studied by cyclic voltammetry, fluorescence spectra SPS and FISPS. The results show that porphyrins are p-type semiconductor. Fluorescence spectra show the dimmer has stronger fluorescence properties than the monomer.