The trivalent and divalent lanthanide complexes reported are, to date, the first homoleptic η recorded during this whole procedure. Alternating current (AC) susceptibility data were recorded on a Quantum Design MPMS XL SQUID magnetometer in the frequency window of 0.1 Hz -1500 Hz. Measurements have been performed either with or without an additional external DC field, for every data set the DC field is given. The amplitude of the alternating field was 5 Oe. For 2-Dy ab inito CASSCF/RASSI/SINGLE_ANISO calculations were performed using OpenMolcas. The input structure was taken from the x-ray crystallographic structure refinement without further optimization. All basis sets were taken from the internal ANO-RCC library and the size of the basis sets was assigned as follows: VTZP (for Dy), VDZP (for Sn, K, O and the 8 C's of the stannole rings), VDZ (all others). The CASSCF were performed individually including the highest possible number of CI roots (21, 224 and 490 for sextet, quartet and doublet respectively) and of those 21, 128 and 130 were employed in the RASSI routine.