The Syntheses And Liquid Crystal Properties Of Meso-tetrakis(4-alkylaminoformylphenyl)Porphyrins And Their Complexes

Porphyrins are a series of the homologue and derivative of porphine with substituent group at the outside ring. When the metal ion displaces two protons at inside ring, metalloporphyrin is made up. They are a kind of special macrocyclic compounds which have twelve active positions that can link with different flexible side chains. Porphyrins and their metal complexes are found in a variety of vital biological systems, such as chlorophyll, cytochrome and hemoglobin molecules. As the particular structure, properties and the nature of the porphyrins and their metal complexes, they are important in the field of biochemistry, synthetic chemistry, applied chemistry and material science, etc. More and more researches of porphyrin derivative are active.In this paper, the synthesis, applications and properties of prophyrins were reviewed. meso-tetrakis(4-alkylaminoformylphenyl)porphyrins and their complexes were prepared, and their liquid crystalline properties were studied. Firstly,4-carboxybenzaldehyde reacted with pyrrole and yielded meso-tetrakis(4-carboxylphenyl)porphyrin(TCPP). Then TCPP and dimethylsulfoxide formed the meso-tetrakis(4-chloroformylphenyl)porphyrin(TCFPP) in CHCl3. The six species of porphyrin compounds,meso-tetrakis(4-octylaminoformylphenyl)-porphyrin(8AFPP), meso-tetrakis(4-decylaminoformylphenyl)porphyrin(10AFPP), meso-tetrakis(4-dodecylaminoformylphenyl)porphyrin(12AFPP),meso-tetrakis(4-tetradecylamino-formylphenyl)porphyrin(14AFPP), meso-tetrakis(4-hexadecylaminoformylphenyl)porphyrin (16AFPP), meso-tetrakis(4-octadecylaminoformylphenyl)porphyrin(18AFPP), were synthesized with TCFPP and n-octylamine, n-decylamine, n-dodecylamine,n-tetradecylamine, n-hexadecylamine, n-octadecylamine in CH2Cl2 at room temperature respectively. Then they reacted with CoCl2, CdCl2, NiSO4, ZnSO4 respectively and twenty-two species of metalloporphyrins were prepared by them. The 8AFPP,10AFPP,12AFPP,14AFPP and their complexes, as well as the complexes of 16AFPP and 18AFPP were new compouds. Their structures of porphyrins and complexes were characterized by means of IR, UV-Vis and’H NMR. Their liquid crystalline properties were investigated by DSC and polarization microscope. The porphyrins of 8AFPP,10AFPP,12AFPP,14AFPP,16AFPP,18AFPP exhibit the speciality of liquid crystal behavior. The metalloporphyrins of 14AFPPCd,16AFPPCd, 18AFPPCd,12AFPPNi,14AFPPNi,16AFPPNi, 14AFPPZn,18AFPPZn,14AFPPCo also exhibit the speciality of liquid crystal behavior. They are all the enantiotropic type of thermotropic liquid crystal.