Structural diversity in the series of lanthanide complexes [Ln(Ph3PO)n(NCS)3] (n = 3, 4)

Two unique series of lanthanide complexes [Ln(Ph3PO)4(NCS)3] (Ln = La-Tb, except Pm) and [Ln(Ph3PO)3(NCS)3] Sm-Lu, Y) have been structurally characterised. The isomorphous crystallises in the monoclinic centrosymmetric space group P21/c, metals display a capped octahedral coordination geometry. In contrast, crystallise non-centrosymmetric R3, with metal displaying an geometry; fac-isomer being observed all cases. Intriguingly, for Sm-Tb both seven six coordinate can be isolated from respective synthetic routes suggesting structural equilibrium solution. An analysis distortions ligand polyhedron two using continuous shape measurement (CShMs) method suggests trends across relating to fit ligands size ions.