(2-Ln, Ln = Tm, Yb), by the SET reactions of TEMPO • with the parent near-linear Ln 2+ complexes 1-Ln; analogously to 2-Sm, the Tm and Yb analogues contain TEMPO -anions. The separate reactions of the bent Ln 3+ complexes 3-Ln with TEMPO • provided the approximately trigonal planar Ln 3+ complexes [Ln{N(Si i Pr3)2}2(TEMPO)][B(C6F5)4] (4-Ln; Ln = Sm, Tm, Yb), which contain TEMPO • radicals. The electronic structures of structurally similar 2-Ln and 4-Ln cations were analyzed by UV-vis-NIR and EPR spectroscopy, magnetic measurements and ab initio calculations. We find evidence of large CF splitting in Yb and Tm complexes, but no slow relaxation behavior for 2-Yb despite the highly pure ground state. Exchange interactions with TEMPO • radicals are estimated as no more than tens of wavenumbers, with 4-Yb having exchange states split by ~0.32 cm -1 and spindle-shaped hysteresis.