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Highly Twisted 1,2:8,9‐Dibenzozethrenes: Synthesis, Ground State, and Physical Properties
Author(s) -
Sun Zhe,
Zheng Bin,
Hu Pan,
Huang KuoWei,
Wu Jishan
Publication year - 2014
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201402127
Subject(s) - singlet state , ground state , absorption (acoustics) , chemistry , photochemistry , molecule , palladium , absorption spectroscopy , infrared , catalysis , band gap , computational chemistry , chemical physics , materials science , atomic physics , organic chemistry , excited state , physics , quantum mechanics , optics , optoelectronics , composite material
Two soluble and stable 1,2:8,9‐dibenzozethrene derivatives ( 3 a,b ) are synthesized through a palladium‐catalyzed cyclodimerization reaction. X‐ray crystallographic analysis shows that these molecules are highly twisted owing to congestion at the cove region. Broken‐symmetry DFT calculations predict that they have a singlet biradical ground state with a smaller biradical character and a large singlet–triplet energy gap; these predictions are supported by NMR and electronic absorption measurements. They have small energy gaps and exhibit far‐red/near‐infrared absorption/emission and amphoteric redox behaviors.