Complexes 2-Ln and 4-Ln were probed by multinuclear NMR spectroscopy as d6-benzene and d2-DCM solutions, respectively (see SI for all spectra). In all cases C{ 1 H} and Si DEPT NMR spectra only showed signals from minor diamagnetic impurities due to the paramagnetism of these samples. 1 H NMR spectra were recorded for 2-Ln and 4-Ln from -200 to +200 ppm due to large paramagnetic shifts; the spectra of Tm 3+ and Yb 3+ derivatives could not be fully interpreted, though signals for the methyl protons on Si i Pr3 groups were tentatively assigned in each case due to the large integration of these peaks (72 H) compared to those expected for other proton environments (≤12 H). The assignment of the 1 H NMR spectra of Sm 3+ complexes was more straightforward as