Bis{6,6′-dimeth­oxy-2,2′-[ethane-1,2-diyl­bis(imino­methyl­ene)]diphenolato(1.5−)-κ(4) O,N,N′,O′}erbium(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.