Nitrogen Analogues of o‐Quinodimethane with Unexpected non‐Kekulé Diradical Character
Tao Li; Cheng Cheng; Ningning Yuan; Lei Wang; Chao Chen; Gengwen Tan; Xinping Wang
Index: 10.1002/cjoc.201700801
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Abstract
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 (12+) has been crystalized and isolated. SQUID measurements, single crystal X‐ray diffraction and theoretical calculations show 12+ has unexpected non‐Kekulé diradical character, sharply different from o‐quinodimethane.