catena-Poly[[[triaqua-europium(III)]-µ-(1H-benzimidazole-5,6-dicarboxyl-ato-κO:O)-µ-(1H,3H-benzimidazol-3-ium-5,6-dicarboxyl-ato-κO:O,O)] dihydrate].

In the title one-dimensional coordination polymer, {[Eu(C(9)H(4)N(2)O(4))(C(9)H(5)N(2)O(4))(H(2)O)(3)]·2H(2)O}(n), one of the 1H-benzimidazole-5,6-dicarboxyl-ate (Hbdc) ligands is protonated at the imidazole group (H(2)bdc). The Eu(III) ion is eight-coordinated by two O atoms from two Hbdc ligands, three O atoms from two H(2)bdc ligands and three water mol-ecules, showing a distorted square-anti-prismatic geometry. The Eu(III) ions are bridged by the carboxyl-ate groups of the Hbdc and H(2)bdc ligands, forming a chain along [110], with an Eu⋯Eu separation of 5.4594 (3) Å. These chains are further connected by inter-molecular O-H⋯O, N-H⋯O and N-H⋯N hydrogen bonds, as well as π-π inter-actions between the imidazole and benzene rings [centroid-centroid distances = 3.558 (3), 3.906 (2), 3.397 (3), 3.796 (2) and 3.898 (2) Å], into a three-dimensional supra-molecular network.

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, [Cd(3)(C(8)H(5)N(2)O(2))(2)(SO(4))(2)(H(2)O)(3)](n), contains three Cd(II) ions, two sulfate anions, two 1H-benzimidazole-5-carboxyl-ate (H(2)bic) ligands and three coordinated water mol-ecules. One Cd(II) ion is six-coordinated and exhibits a distorted octa-hedral geometry, while the other two Cd(II) ions are seven-coordinated, displaying a distorted penta-gonal-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 H(2)bic ligands, leading to a three-dimensional framework. N-H⋯O and O-H⋯O hydrogen bonds and π-π inter-actions 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.

catena-Poly[silver(I)-µ-acridine-9-carboxyl-ato-κN:O,O'].

In the title coordination polymer, [Ag(C(14)H(8)NO(2))](n), the Ag(I) cation is coordinated by two O atoms and one N atom from two symmetry-related acridine-9-carboxyl-ate ligands in a distorted trigonal-planar geometry. The metal atoms are connected by the ligands to form chains running parallel to the b axis. π-π stacking inter-actions [centroid-to-centroid distances 3.757 (2)-3.820 (2) Å] and weak Ag⋯O inter-actions further link the chains to form a layer network parallel to the ab plane. The Ag(I) cation is disordered over two positions, with refined site-occupancy factors of 0.73 (3):0.27 (3).