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Wurster‐Type Nanographenes as Stable Diradical Dications
Author(s) -
Desroches Maude,
Morin JeanFrancois
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201706081
Subject(s) - diradical , steric effects , electron paramagnetic resonance , ground state , antiaromaticity , chemistry , photochemistry , crystallography , aromaticity , singlet state , molecule , excited state , stereochemistry , nuclear magnetic resonance , organic chemistry , atomic physics , physics
Three new and stable diradical dications based on the 4,10‐dibromoanthanthrone have been synthesized and characterized. In their dicationic state, the amines show a biradical character in the ground state. Their magnetic properties have been investigated by NMR and EPR spectroscopies. The dicationic salts shows strong and broad optical absorption in the near‐infrared region. The main driving force to obtain a ground state biradical is the high steric hindrance that prevents planarization of the diphenylamines with the anthanthrone aromatic core. The radical cations are isolated in two perpendicular π‐systems as demonstrated by X‐ray diffraction structures. This work provides a new bridging unit in the search for biradical bis(triarylamines) salts.