5,5,15,15-Tetraoxo-5,15-Dithiaporphyrin as a Highly Electron-Deficient Porphyrinic Ligand

Atsumi Yagi; Takeshi Kondo; Daisuke Yamashita; Naruhiko Wachi; Hiroto Omori; Norihito Fukui; Takahisa Ikeue; Hiroshi Shinokubo

doi:10.1002/chem.201903639

5,5,15,15-Tetraoxo-5,15-Dithiaporphyrin as a Highly Electron-Deficient Porphyrinic Ligand

Chemistry. 2019 Dec 5;25(68):15580-15585. doi: 10.1002/chem.201903639. Epub 2019 Nov 4.

Authors

Atsumi Yagi¹, Takeshi Kondo¹, Daisuke Yamashita¹, Naruhiko Wachi¹, Hiroto Omori¹, Norihito Fukui¹, Takahisa Ikeue², Hiroshi Shinokubo¹

Affiliations

¹ Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Japan.
² Department of Chemistry, Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue, 690-8540, Japan.

PMID: 31550386
DOI: 10.1002/chem.201903639

Abstract

Oxidation of 5,15-dithiaporphyrin with meta-chloroperbenzoic acid afforded the corresponding S,S-tetraoxide in good yield. The resultant 5,5,15,15-tetraoxo-5,15-dithiaporphyrin exhibited the highly electron-deficient nature as elucidated by the electrochemical analysis and theoretical calculations. Treatment of tetraoxodithiaporphyrin with zinc(II) acetate and nickel(II) acetate provided the corresponding metal complexes efficiently. Owing to its enhanced Lewis acidity of the metal center by the electron-deficient ligand, the nickel complex underwent facile axial ligation to form pentacoordinate and hexacoordinate high-spin (S=1) complexes in solution and solid, respectively. The binding constant of pyridine to the Ni^II center was significantly higher than those of conventional porphyrin Ni^II complexes. Temperature-dependent magnetic susceptibility measurements of the high-spin Ni^II complex revealed the presence of weak ferromagnetic interactions.

Keywords: Lewis acids; ligands; magnetism; porphyrinoids; sulfones.

Abstract

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