Main Group Metal−Actinide Magnetic Coupling and Structural Response Upon U4+ Inclusion Into Bi, Tl/Bi, or Pb/Bi Cages
Résumé
The encapsulation of actinide ions in intermetalloid clusters has long been proposed but was never realized synthetically. We report the isolation and
experimental, as well as quantum chemical, characterization of the uranium-centered clusters [U@Bi12]3−, [U@ Tl2Bi11]3−, [U@Pb7 Bi7]3−, and [U@Pb4 Bi9]3−, upon reaction of (EE′Bi2)2− (E = Ga, Tl, E′ = Bi; E = E′ = Pb) and [U(C5Me4H)3] or [U(C5Me4H)3Cl] in 1,2- diaminoethane. For [U@Bi12]3−, magnetic susceptibility measurements rationalize an unprecedented antiferromagnetic coupling between a magnetic U4+ site and a unique radical Bi12
7− shell.