Synthesis And Structual And Spectral Properties Of Dome-type Nonplanar Porphyrins

Heme has a strong catalytic oxidizability by the configuration of the large ring ofporphyrin distortions. In our preliminary work, we found that porphyrin with the4-Ncore contraction could contribute to stabilize the highly-charged metal irons directly.The main purpose of this subject is to investigate the influence of the larger4-N coreon stabilizing the low-valent metal irons. For this reason, we designed andsynthesized a dom-type non-planar porphyrin as a model compound. In the study weoptimize the synthesis conditions of these compounds, track the spectral changesbefore and after complexation with metal and explore the stabilization for insertinglow-valent metal irons [such as Fe (II)].By carefully analyzing the structure of distorted porphyrin reported nowadays,we found that the4-N core in distorted porphyrin is smaller than it in plane porphyrin,which can not accord with the size requirementsthe when the same metal ion valencereduced, so the design and synthesis the porphyrins with a big size of4-N cavity is thekey to our subject. In order to abtain a porphyrin with larger size of4-N core, wedesigned a capped porphyrin, and the cap is benzene which is smaller than porphyrinplane by linked four short alkyl chains to the meso site of porphyrin and in thiscomformation, four pyrrole N atoms are all out-of-plane. The target compound(BzTtPP) was synthetized successfully as well as its metal complexes BzTtPPCu,BzTtPPZn, BzTtPPFe(Ⅲ) and BzTtPPFe(Ⅱ). The size enlargement compared toplane conformation was confirmed by the crystal structure of BzTtPP and BzTtPPCu,and this enlarged core has the potential of stable low valence and large-size metal ion.In our research, we optimized synthesis condition from reaction temperature, choiceof solvent, acid strength and reaction timea etc. The result show that acetic acid: acid:nitrobenzene volume ratio of1:1:3, reaction temperature110℃, reaction time of3h,model compound withgood yield (0.25%). By compared the UV-visible absorption ofBzTtPPFe(Ⅲ) and BzTtPPFe(Ⅱ), confirmed the fact that the enlarged porphyrincavity really can stable ferrous iron, more direct evidence is still in research. Ourresearch for the simulation of the heme macrocycle distorted provides a new modelcompounds, the experimental results could demonstrated in some degree that thevalence state in porphyrins is related to the size of porphyrin ring. The target productand intermediate compounds were confirmed by1H NMR, HH COSY,13C NMR, HR-MS, UV-vis, X-ray.