Asymmetric Porphyrin Synthesis And Properties Of Complexes

The application of synthetic metalloporphyrins as the model enzymesof cytochrome P450 is the hot topic of porphyrin chemistry. The electronic andsteric effect of the substituents in phenyl of porphyrins are very important forcatalytic activity and the axial coordination properties, as well as the functionalgroups attached to the porphyrin ring.In the paper we extend thes approach to synthesize two new asymmetricalporphyrins, 5 -(4-phenylacetyliminemethoxy)phenyl-10, 15,20-triphenylporphyrin(PR),5 -(4-phenylacetyliminemethoxy)phenyl-10, 15,20-tri(p-methoxylphenyl)porphyrin(POR)and their metal complexes (Co, Mn,Zn) as model of cytochromeP450. It seems that there compounds have not been reported before The aim-porphyrin have been synthesized by the reaction of mono hydroxylporphyrinand aniline with chloracetyl chloride .The chemical structure of allcompounds were identified by elementary analysis, infrared spectra, nuclearmagnetic resonance spectra, ultraviolet-visible spectra, we still developeffective synthetic condition of mono substituented porphyrin. In the presence of asymmetrical metalloporphyrins [Co(Ⅱ)PR, Mn (Ⅲ)PORCl, Co(Ⅱ)POR],the oxidation of benzaldehyde with molecula oxygenhas been investigated. The oxygen uptake and changes in the electronic spectrum of metalloporphyrins during the course of reaction were measured. Itwas observed the complexes can all catalyze the oxidation of benzalde hydewhile H₂P and Zn(Ⅱ)POP is inactive. The order of O₂ maximum up takingrates(mL\min) (30℃) are MnPORCl (3.8) > CoTMOP≈ CoPOR (3.3 ) > CoPR(2.3) .The temperature and electronic effect during the course is alsodiscussed. We then study the catalytic activity of Mn(Ⅱ)PORCl for theepoxidation of cyclohexene by use of the Mn (Ⅲ) PORCl,Zn,CH₃COOH andIm is measured. It also has good catalytic activity.The coordination properties between new asymmetrical porphyrinszinc(11)with nitrogenous llgands were Investigated by UV－Visspectroscopic method．The visible spectra of porphyrin zinc(11)changesquite differentlywiththe addition ofllgands In dlchloromethane atroomtemperature．We discussed Indetallthe electronic and asymmetrlcaleffectsInporphyrlns andthe effects ofllgands duringthe course．Bymeans ofv！slble spectral technique and the miller－dorough method, the equi！ibriumconstant(K)and stolchlometrlc number(n)of coordination reaction aredetermined between porphyrlns zinc(11)and llgands．The steric andelectronic effects of＊thes llgands onthe reaction andthe substltuents ofporphyrln on the stability ofcomplex were studied．M also foundthatthevalue ofKofasymmetrlcalporphyrlnZlnc Is sllghtlygreaterthanthesymmetrical ones with analogue construction．...