4,4′- and 2,4′-Bis(olympicenyl)s: Antiferromagnetically Coupled Diradicals with Twisted Conformations

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.