Poly[[tetraaquatetrakis[μ3-5-(pyridine-4-carboxamido)isophthalato]cobalt(II)dierbium(III)] tetrahydrate

Abstract

In the centrosymmetric polymeric title compound, {[CoEr2(C14H8N2O5)4(H2O)4]·4H2O}n, the ErIII cation has a coordination number of eight and is surrounded by seven carboxyl­ate O atoms from four 5-(pyridine-4-carboxamido)­isophthalate (L) ligands and one water mol­ecule, forming a distorted square-anti­prismatic arrangement. The CoII cation is located on an inversion center and is coordinated by two pyridine N atoms, two carboxyl­ate O atoms and two water mol­ecules in a distorted octa­hedral geometry. The asymmetric unit contains two anionic L ligands. One bridges two ErIII cations and one CoII cation through two carboxyl­ate groups and one pyridine N atom, while the other bridges two ErIII cations and one CoII cation through two carboxyl­ate groups. Extensive O—H⋯O, O—H⋯N and N—H⋯O hydrogen-bonding inter­actions are present in the crystal, involving all uncoordinated water mol­ecules and the uncoordinated pyridine N atom of one of the ligands bonded to an adjacent coordinated water mol­ecule. The title compound is isotypic with the gadolinium analogue.