catena-Poly[tris-(μ(2)-1H-benzimidazole-5-carboxyl-ato)europium(III)]

Bis[2-(1H-benzimidazol-2-yl)acetato-κ2N3,O]bis(ethanol-κO)nickel(II)

In the title compound, [Ni(C₉H₇N₂O₂)₂(C₂H₅OH)₂], the Ni^II ion is situated on an inversion center and is coordinated by two N and two O atoms from two 2-(1H-benzimidazol-2-yl)acetate (L) ligands and by two O atoms from two ethanol ligands in a distorted octa­hedral geometry. In the L ligand, the acetate group deviates significantly from the benzimidazole plane, the C—C—C—O(coordinating) torsion angle being 34.2 (5)°. In the crystal, O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules into a two-dimensional supra­molecular network parallel to the bc plane.

Poly[μ-aqua-diaqua(μ(3)-1H-benzimid-azole-5-carboxylato-κN:O,O')(μ(2)-1H-benzimidazole-5-carboxylato-κN:O:O')-μ(5)-sulfato-μ(4)-sulfato-tri-cadmium]

The asymmetric unit of the title compound, [Cd₃(C₈H₅N₂O₂)₂(SO₄)₂(H₂O)₃]_n, contains three Cd^II ions, two sulfate anions, two 1H-benzimidazole-5-carboxyl­ate (H₂bic) ligands and three coordinated water mol­ecules. One Cd^II ion is six-coordinated and exhibits a distorted octa­hedral geometry, while the other two Cd^II ions are seven-coordinated, displaying a distorted penta­gonal–bipyramidal geometry. The Cd^II ions are bridged by two types of sulfate anions, producing inorganic chains along [100]. These chains are further connected by the H₂bic ligands, leading to a three-dimensional framework. N—H⋯O and O—H⋯O hydrogen bonds and π–π inter­actions between the imidazole and benzene rings [centroid–centroid distances = 3.953 (2), 3.507 (2), 3.407 (2) and 3.561 (2) Å] further stabilize the crystal structure.