Synthesis And Properties Of The Meso-substituted Asymmetric Porphyrin As Semiconductor Materials

Porphyrins have broad applications in the fields of biology, medical science, analytical chemistry and materials chemistry ect, owing to its special structure of the conjugate plane. Asymmetric prophyrins play an important role in these fields. Today asymmetric prophyrins still attract scientist.we synthesis a series of meso-substituted asymmetric porphyrins, hydroxyl porphyrin liked with different kinds of pyridine carbosylic acid. It is possible to realize the dual activity of porphyrin and pyridine carboxylic acid. Then their structure and propeties have been studied in detail. All these studies provide useful information for the research of self-assembly materials and anticancer drug carrier.The hydroxyl porphyrin with different subsituents (OCH3,H,Cl) were synthesized by Adler reaction. The taget product wre synthesized by two stpes SN reaction. The diversified porphyrins were synthesized by this methods, and It is need mild reaction conditions.Five meso-substituted asymmetric porphyrins were synthesized, all of them have been characterized by UV-Vis, IR, EA, MS and 1H NMR. 1.Theoretical Investigations:Electronic structure calcalation was based on density function theory(DFT). We simulated the stable conformation of the porphyrins, and calculated the total energy, HOMO energy and LUMO energy of the porphyrins. Through the analysis of data, We know the band gap of porphyrins, which is semiconductor materials.2.UV-Vis:According to Kubelka-Munk equation, we get optical absolution spectrum from UV-Vis spectrum. We can see the band gap from the absolution spectrum. The band gap has a range of 1.74～1.82eV, all the porphyrins are semiconductor materials.3.SPS:Because of the transition ofπ→π*, the SPS of the porphyrins are similar with their corresponding UV-Vis specturm. The results show that porphyrins are semiconductor.4.Fluorescence emission spectra:The clcetron-donor group (CH3) makes the intensity of fluorescence emission spectra and the quantum field increase, however, the electron-attracting group (Cl) makes it in reverse.5.Raman spectra:The 1550cm-1 band of the five porphyrins is assigned to the vibration of Cβ-Cβ; the bands at 1548-1551cm-1,1491～1496cm-1,1238-1241cm-1, 1080～1085cm-1 are the skeleton vibration of porphyrins; the 999～1001cm-1 and 885cm'1 bands are the characteristic bands of the phenyl on the TPP; the 962cm-1 band is assigned to the vibration of N-H.6.Molecular morphology:The AFM image shows us the porphyrins aggregated, owing to the noncovalent forces of porphyrins.