Er(III) and Yb(III) Complexes with a Tripodal Nitroxyl Radical: Magnetochemical Study and Ab Initio Calculations

In this paper, we investigate the magnetic exchange interaction and magnetization dynamics of two new members of the [LnRad(NO3)3] family, where Rad is a tripodal nitroxide, and Ln is Er(III) or Yb(III), having the prolate type electron density. Single OK crystal and powder X-ray diffraction studies showed that these complexes are isostructural with their previously investigated Y, Gd, Dy, Tm, Tb, Eu, and Lu congeners. A magnetometric investigation, supported by ab initio calculations, showed the presence of antiferromagnetic coupling between the lanthanide ion and the radical in both compounds with estimated J values of ≈7 and ≈20 cm−1 for Er and Yb, respectively (+J Seff∙ S formalism).