Highly twisted 1,2:8,9-dibenzozethrenes: Synthesis, ground state, and physical properties
KAUST DepartmentKAUST Catalysis Center (KCC)
Physical Sciences and Engineering (PSE) Division
Chemical Science Program
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AbstractTwo soluble and stable 1,2:8,9-dibenzozethrene derivatives (3a,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 farred/near-infrared absorption/emission and amphoteric redox behaviors.
SponsorsJ.W. acknowledges financial support from the BMRC grant (10/1/21/19/642), MOE Tier 2 grant (MOE2011-T2-2-130), and MINDEF-NUS JPP (Grant 12-02-05). K.W.H. acknowledges support from MUST. We thank Dr. Tan Geok Kheng for the crystallographic analysis of 3b.
Is Supplemented BySun, Z., Zheng, B., Hu, P., Huang, K.-W., & Wu, J. (2014). CCDC 980734: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc11xjl2