Spontaneous Formation of an Air-Stable Radical upon the Direct Fusion of Diphenylmethane to a Triarylporphyrin.
The direct fusion of a diphenylmethane segment to a Ni(II) 5,10,15-triarylporphyrin with three linkages furnished an air- and moisture-stable neutral radical through unexpected and spontaneous oxidation. This radical was demetalated by treatment with H2 SO4 and CF3 CO2 H 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.
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
Kenichi
K
Kato
Spectroscopy Laboratory of Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
Wonhee
W
Cha
Spectroscopy Laboratory of Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea.
Juwon
J
Oh
Center for Instrumental Analysis, Niigata University, Nishi-ku, Niigata, 950-2181, Japan. kou-f@chem.sc.niigata-u.ac.jp.
Ko
K
Furukawa
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan. yori@kuchem.kyoto-u.ac.jp.
Hideki
H
Yorimitsu
Spectroscopy Laboratory of Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 120-749, Korea. dongho@yonsei.ac.kr.
Dongho
D
Kim
Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan. osuka@kuchem.kyoto-u.ac.jp.
Atsuhiro
A
Osuka
aromaticity; fused-ring systems; porphyrinoids; radical; redox chemistry