Structural variations in a series of lanthanide nitrate complexes with an unsymmetrical diphosphonate ligand (MeO)2P(O)C(CH2)CH2P(O)(OMe)2

► In this study we examine lanthanide nitrate complexes of (MeO)2P(O)C(CH2)CH2P(O)(OMe)2 (L). ► Complexes with compositions Ln(NO3)3L2 (Ln = La-Gd) and Ln2(NO3)6L3 (Ln = Tb-Lu) were isolated. ► In Ln(NO3)3(L)2 the metal is 10-coordinate with bidentate nitrates and L. ► Ln2(NO3)6L3 has 9-coordinate metals with bidentate nitrates, one chelating and one bridging L. ► NMR studies indicate the structures are retained in solution.