Synthesis And Characterization Of Unsymmetrical Schiff-base Porphyrins And Their Complexes

The porphyrin and their related complexes with abadnt physicochemical properties were commonly used in the preparation of functional molecular materials and the light emitting materials. Schiff base compounds with the the-C=N-double bond configuration supplied strong coordination ability owing to the lone pair electrons from the hybrid orbital on the N atom, and therefore they have been widely investigated and graduately become the hot research in the field of chemistry, materials, biology and medicine, Schiff base is very conviniencely prepared by congdensation of amino-derivatives with different aldehydes or ketones. By reaction of5,10-bis(4-aminophenyl)-15,20diphenyl porphyrin with different para/-a-substituted benzaldehyde, a series of asymmetric Schiff-base porphyrins were synthetized and their metal complexes were also prepared. The different substituents around porphyin chromophores caused changes in their electronic effects, resulting in their porperties and spectrum performance changes. The specific content of the paper can be divided into the following sections:Chapter Ⅰ:The synthetic methods and development of porphyrin compounds were reviewed at home and abroad. Close attention was paid to the synthesis and application about metalloporphyrins.Chapter Ⅱ:Introduces of the synthesis of meso-tetra-carboxyphenyl porphyrin and its metal complexes, and these compounds were characterized by1H-NMR, FT-IR, UV-Vis, EPR and fluorescence spectroscopy (FL). This part is based on basic experiments for preparing and characterizing porphyrin derivatives.Chapter Ⅲ:Synthesis of5,10-bis (4-aminophenyl)-15,20diphenyl porphyrin. After synthesis of meso-tetraphenyl porphyrin (TPP), and using it reacting with controlled amount of sodium nitrite, the reaction time.5,10-bis(4-nitrophenyl)-15,20diphenyl porphyrin(H2BNPDPP) was synthesised. H2BNPDPP then was reduced by SnCl2in concentrated hydrochloric acid,5.10-bis(4-aminophenyl)-15,20diphenyl porphyrin(H2BNPDPP) was synthesized and it was characterized by’H-NMR, FT-IR, UV-Vis, EPR and fluorescence spectroscopy (FL). Comparing with its precursor of H2TPP, the spectorpic behaavior of H2BNPDPP exhibited more differences.Chapter Ⅳ:Synthesis of unsymmetrical Schiff-base porphyrins and their metal complexes. The mentioned compounds were abtained by condensation of5,10-bis(p-aminophenyl)-15.20dihenyl porphyrin with different para-substituted benzaldehydes, and then the abotained product reacted with cobalt acetate and zinc acetate, the related asymmetric Schiff-base Zn porphyrins and Co porphyrins were prepared. These compounds were also characterized by H-NMR. FT-IR, UV-Vis and fluorescence spectroscopy (FL) method; fllowed by investigation of their spectorsocpic behavor.Chapter V:Chemical chromism of metal free porphyrins. A series of weso-substituted phenyl porphyrin derivatives were selected for investigating their photochromic behavior in several aryl chloride solutions. After ultraviolet irradiation (UVI, λ<360nm), the solutions’ color changed rapidly and sensitively from pink into bright green; and their pink color can be recovered gradually when the green samples were radiated under visible light (VR. λ>500nm) or placed around diffused light at ambient conditions. Notably this photochromic behavior can be completely stimulated by a chemical chromic method. A porphyrin H2TMPP was selected as a typical sample for revealing this chromic mechanism, and molecular configuration for the green porphyrin chromophores was proposed based on crystal assembly of H2TPP. Finally the sensitively molecular recognition of H2TMPP towards hvdrochlorides was examined.