Contrasting the well-known homoleptic group 13 and 15 dysprosocenium SMMs, the analogous monomeric group 14 dyprosocenium anion [Dy(L)2] -has remained elusive due to synthetic challenges. Moreover, while compounds with Si, Ge and Pb metallole ligands have been established in the last three years, the dianionic stannole has only been utilized for transition metals for a long time and only very recently been incorporated in the COT-Er SMM IX. This gap in knowledge has led us to target the synthesis of homoleptic Ln bisstannolediide complexes, aiming to explore a new frontier in lanthanide SMM chemistry considering both the unique structure motif and promising magnetic properties. Fig. Selected example of rare-earth metal compounds with dianionic heavy group 14 cyclopentadienides. Si = SiMe3 in I-III and V-IX; Si = SitBuMe2 in IV.