LAUSR

Abstract From the high-frequency electron paramagnetic resonance spectra on [Ln(hfac)3(TMIO)2] (Ln = Tb, Dy; TMIO = 1,1,3,3-tetramethylisoindolin-2-oxyl; hfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dionate) the level-crossing fields of the radical signal of the Tb and Dy complexes were determined to be 21.9(3) and 20(2) T, respectively. The observation of a single signal is consistent with the two-fold molecular symmetry. The coupling constants were evaluated, giving JTb-rad/kB = −4.47(4) K and JDy-rad/kB = −3.2(4) K. Since the exchange coupling constant in [Gd(hfac)3(TMIO)2] has already been determined to be JGd-rad/kB = −12.5(4) K from the magnetic susceptibility measurements, the lanthanide-dependence on |JLn-rad| was concluded as |JGd-rad| > |JTb-rad| > |JDy-rad| in this series.