Bis{6,6′-dimethoxy-2,2′-[ethane-1,2-diylbis(iminomethylene)]diphenolato(1.5−)-κ4O,N,N′,O′}terbium(III)

In the title compound, [Er(C(18)H(22.5)N(2)O(4))(2)], the Er atom is located on a twofold rotation axis and is eight-coordinated by four O atoms and four N atoms from two symmetry-related 6,6'-dimethoxy-2,2'-(ethane-1,2-diyldiiminodimethylene)diphenolate(1.5-) ligands. Due to disorder of one phenolate H atom with half-occupation, the overall charge of one tetradentate ligand is -1.5. The ligand molecules are stabilised by intramolecular N-H⋯O and O-H⋯O hydrogen bonds and are linked into a chain parallel to the a axis by a C-H⋯O hydrogen bond. Neighbouring chains are connected by van der Waals forces, resulting in a three-dimensional network.