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4,4'- and 2,4'-Bis(olympicenyl)s: Antiferromagnetically Coupled Diradicals with Twisted Conformations
Yuping Song1, Tianyu Jiao2, Weiwei Niu3
1Institute of Molecular Plus, Department of Chemistry, Tianjin University and Haihe Laboratory of Sustainable Chemical Transformations, 92 Weijin Road, Tianjin 300072, P. R. China.
None:
4,4'- and 2,4'-bis(olympicenyl) diradicals with twisted conformations were synthesized, and their magnetic properties were elucidated. Contrary to predictions of antiferromagnetic coupling for the 4,4'-diradical and ferromagnetic coupling for the 2,4'-diradical, both exhibit antiferromagnetic coupling with similarly small singlet-triplet gaps (-0.27 and -0.30 kcal/mol). A spatially segregated two-spin model yields spin-spin distances of 5.2 and 6.0 Å. Both display long spin relaxation times. These findings provide insight into the rational design of molecular spin materials.
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