The direct fusion of a diphenylmethane segment to a NiII5,10,15-triarylporphyrin with three linkages furnished an air- and moisture-stable neutral radical through unexpected and spontaneous oxidation. This radical was demetalated by treatment with H2SO4and CF3CO2H to provide the corresponding free-base radical. These porphyrin radicals are very stable owing to spin delocalization and have been fully characterized through UV/Vis/NIR absorption spectroscopy, X-ray crystallographic analysis, magnetic susceptibility measurements, electrochemical studies, laser-based ultrafast spectroscopic studies, and theoretical calculations. They were chemically oxidized and reduced to the corresponding cation and anion but did not react with hydrogen-atom donors.
Bibliographical noteFunding Information:
The research at Kyoto was supported by Grants-in-Aid from MEXT (No.: 25107002 ?Science of Atomic Layers?) and from JSPS (No.: 25220802 (Scientific Research (S)), 24685007 (Young Scientists (A)), and 26620081 (Exploratory Research)), and by ACT-C, JST. We thank Prof. Dr. Hiroshi Kitagawa and Dr. Kazuya Otsubo (Kyoto University) for XRPD measurements. H.Y. thanks Kansai Research Foundation for Technology Promotion and The Asahi Glass Foundation for financial support. The research at Yonsei University was supported by the Ministry of Science, ICT & Future, Korea through the Global Research Laboratory Program (2013K1A1A2A02050183).
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