177841-46-2Relevant articles and documents
N-Confused Porphyrin Metal Complexes with an Axial Pyridine Directly Tethered from an Inner Carbon: A Bioinspired Ligand as a Versatile Platform for Catalysis
Miyazaki, Takaaki,Yamamoto, Takaaki,Mashita, Shunichi,Deguchi, Yuya,Fukuyama, Kazuki,Ishida, Masatoshi,Mori, Shigeki,Furuta, Hiroyuki
, p. 203 - 207 (2018)
Bioinspired pentadentate ligand N-confused porphyrin (NCP) bearing a 2-mercaptopyridine group and its RuII and CoIII complexes were synthesized. Their structures were revealed by single-crystal X-ray crystallographic analysis. Installation of an axial thiopyridine ligand shifts the redox potentials negatively and enhances the catalytic activity largely, which was demonstrated in the cyclopropanation reaction using the Co complex.
Formation of Stable NiIII N-Confused Porphyrins Aided by a 3-Ethoxy Group
He, Huowang,Ye, Zongren,Shimizu, Daiki,Sumra, Idrees,Zhang, Yihuan,Liang, Zhengyu,Zeng, Yingyu,Xu, Ling,Osuka, Atsuhiro,Ke, Zhuofeng,Jiang, Hua-Wei
supporting information, (2021/11/10)
We report the synthesis, characterization, and reactivities of two stable NiIII N-confused porphyrin (NCP) complexes. Metalation of 3-OEt NCP 1 with NiCl2 ? 6H2O in CHCl3/EtOH gave 3-OEt NiII NCP 3 initially, which was easily oxidized in air to form the NiIII complex of NCP inner C-oxide 4. Bis-ethoxy-modified NiIII complex 5 was synthesized by oxidation of 3 with PIFA in ethanol and CHCl3. The structures of 4 and 5 were determined by single-crystal X-ray diffraction analysis. An unusually long NiIII?C bond (2.170(9) ?) was observed in 4. The g-factor (g>2.1) observed in the EPR spectra of 4 and 5 further confirmed that they are paramagnetic NiIII complexes. Comparative experiments showed that the 3-ethoxy group plays an important role in the formation of 4 and 5. Reduction of 4 and 5 with NaBH4 regenerated complex 3.
Nickel(II) complexes of 21-C-alkylated inverted porphyrins: Synthesis, protonation, and redox properties
Schmidt, Izabela,Chmielewski, Piotr J.
, p. 5579 - 5593 (2008/10/08)
Reaction of the nickel(II) complex of an inverted porphyrin, (5,10,15,20-tetraphenyl-2-aza-21-carbaporphyrinato)-nickel(II) (1), with haloalkanes in the presence of proton scavengers yields 21-C-alkylated complexes. The products are separated and characterized spectroscopically. Chirality of the formed substituted metalloporphyrins is discussed on the basis of the 1H NMR spectra. Diastereomers are observed for the complexes containing chiral substituents. Protonation of the external nitrogen of the inverted pyrrole is combined with coordination of the apical ligand that leads to paramagnetic nickel(II) complexes. Very strong differentiation of the isotropic shift for diastereotopic methylene protons is observed in 1H NMR spectra of the protonated paramagnetic species. For the systems containing benzyl, allyl, and ethoxymethyl substituents a mild dealkylation in solution of protonated complexes is observed in the presence of oxygen. Redox properties of the alkylated complexes are studied by means of cyclic voltammetry. Oxidation of the nickel center in 21-alkylated systems takes place at the potentials comparable to that of unsubstituted complex 1. Protonation introduces small changes to the potential of the Ni II/NiIII redox couple, but it stabilizes nickel(I) species. Products of chemical oxidation and reduction of the alkylated complexes are detected by means of the EPR spectroscopy indicating in both cases metal-centered redox processes.
