Design And Synthesis Of A Biomimetic Complex Of Heme C_i

Heme Ci is one special heme which has been discovered in cytochrome b6f. It is a five-coordinate high-spin species with OH? or H2O as ligand. It forms hydrogen bonding network with environment which is believed to play an important role in electron transfer and proton transfer. But its function is unclear so far. We are focusing on the model study to provide evidence for the heme Ci's function in biological system. In this thesis, we have designed and synthesized one model complex, and will present those in three sections.Firstly, the designed precursor (5-(8-ethoxycarbonyl-1-naphthyl)-10,15,20- triphenyl-porphyrin) (H2ENTPP) has been synthesized by a one-pot reaction. The compound was characterized by 1H NMR, Mass spectroscopy, IR, CD and X-ray crystallography. Its crystal was crystallized in a chiral space group, and the molecule has conformational chirality. CD spectroscopy has further confirmed the chirality through KBr pellets. Despite the chirality in the solid state, there was no observable signal when a single crystal was dissolved in solution. It suggests that conversions between conformers of porphyrin are possible and racemization could occur in solution. Secondly, the designed ligand of model compound,(5-(8-carbonyl-1-naphthyl)-10,15,20-triphenyl-porphyrin), (H2CNTPP) has been synthesized by the hydrolysis of H2ENTPP. The compound has been characterized by 1H NMR, mass spectroscopy, UV-vis spectroscopy, IR and X-ray diffraction.Thirdly, the complex of [Fe(CNTPP)Cl] has been synthesized from H₂CNTPP. It has been characterized by 1H NMR, UV-vis spectroscopy and X-ray diffraction. The model complex (most likely [Fe(CNTPP)(OH)],[Fe(CNTPP)(H₂O)₂]⁺) has been synthesized from [Fe(CNTPP)Cl] which is identified by 1H NMR.