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Nitrogen Analogues of o ‐Quinodimethane with Unexpected non‐Kekulé Diradical Character
Author(s) -
Li Tao,
Cheng Cheng,
Yuan Ningning,
Wang Lei,
Chen Chao,
Tan Gengwen,
Wang Xinping
Publication year - 2018
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201700801
Subject(s) - diradical , chemistry , electron paramagnetic resonance , character (mathematics) , singlet state , crystallography , ground state , nitrogen , diffraction , photochemistry , atomic physics , nuclear magnetic resonance , excited state , organic chemistry , quantum mechanics , physics , geometry , mathematics
Two‐electron oxidations of three 1,2‐di(bisphenylamino)‐benzenes afforded a class of nitrogen analogues of o ‐quinodimethane. Their electronic structures in the ground state were studied by spectroscopic techniques including EPR and UV‐vis absorption spectroscopy. They have open‐shell singlet ground states with thermally accessible triplet states. One of them ( 1 2+ ) has been crystalized and isolated. SQUID measurements, single crystal X‐ray diffraction and theoretical calculations show 1 2+ has unexpected non‐Kekulé diradical character, sharply different from o ‐quinodimethane.