Synthesis of N-confused Porphyrin Manganese,Iron and Cobalt Complexes and Their Applications
Study on the synthesis and applications of N-confused porphyrin manganese,iron and cobalt complexes has be-come one of the hot topics of porphyrin chemistry.Compared with the coordination chemistry of porphyrin,that of N-confused porphyrin is complicated because of the peripheral nitrogen atom,the intramolecular C—H bond and NH tau-tomerism.N-confused porphyrin has two NH tautomers,isomer A and isomer B.Varied functions are observed in the coordi-nation chemistry of N-confused porphyrin such as stabilization of unusual metal oxidation states and metal-carbon bond for-mation.N-confused porphyrins have flexible character toward the metal oxidation state.Removal of the number of hydrogen atoms from one to three will result in a monanionic,dianionic and trianionic macrocycle.The various metal oxidation states are observed in N-confused porphyrin manganese,iron and cobalt complexes.The monovalent character of N-confused por-phyrin is observed in cobalt chemistry such as CoⅡ(2-N-RNCTPP)Cl and CoⅡ(NCTPP).The cobalt metal takes a valence of+2 since CoⅡ(2-N-RNCTPP)Cl has a monoanionic axial ligand and N-confused porphyrin ligand.The squar-planar Co(Ⅱ)complex CoⅡ(NCTPP)exists the cobalt-carbon bond.The divalent and trivalent characters of N-confused porphyrins are observed in manganese,iron and cobalt chemistry.In Mn(Ⅱ)and Fe(Ⅱ)complexes of N-confused porphyrin MnⅡ(NHCTPP)Br and FeⅡ(NHCTPP)Br,oxidation of the metal center is observed through intramolecular C—H bond activa-tion of N-confused porphyrin ligand,which can be converted into Mn(Ⅲ)and Fe(Ⅲ)complexes MniⅡ(NCTPP)Br and FeⅢ(NCTPP)Br on exposure to air in solutions.{FeNO}6 with a linear Fe-NO conformation is observed in the iron chemistry of N-confused porphyrin,which is unusually stable among the porphyrin iron nitrosyl complexes.It implies that iron N-confused porphyrin complexes can be used to study NO delivery and storage.This review covers the progress on the syn-thesis of N-confused porphyrin manganese,iron and cobalt complexes and their applications in the field of catalytic chemis-try and biological chemistry.The synthesis methods of N-confused porphyrin manganese,iron and cobalt complexes and their applications in catalytic oxidation,cyclopropanation of alkene,nitrate reductase activity and chemical nuclease activity are introduced systematically.
N-confused porphyrin manganese,iron and cobalt complexessynthesisapplication