Xiao-Fei Li

Poly[[[diaqua­sodium]-μ3-5-carb­oxy-2-ethyl-1H-imidazole-4-carboxyl­ato-κ4 N 3,O 4:O 5:O 5] monohydrate]

In the title complex, {[Na(C7H7N2O4)(H2O)2]·H2O}n, the NaI atom exhibits a distorted octahedral geometry and is six-coordinated in an NO5 environment. The equatorial plane is defined by three O atoms and one N atom from two distinct 5-carboxy-2-ethyl-1H-imidazole-4-carboxylate (H2EIDC) ligands and one coordinated water molecule, and the apical sites are occupied by one carboxyl O atom from one H2EIDC ligand and one O atom from the other coordinated water molecule. The NaI atoms are linked by H2EIDC ligands, generating an infinite double chain along the a axis. These chains are further connected via O—H⋯O and N—H⋯O hydrogen bonds into a three-dimensional supramolecular network.

Poly[diaqua­(μ3-1H-benzimidazole-5,6-dicarboxyl­ato-κ4N3:O5,O6:O6′)magnesium(II)]

In the title complex, [Mg(C9H4N2O4)(H2O)2]n, the MgII atom is six-coordinated by one N and three O atoms from three different 1H-benzimidazole-5,6-dicarboxylate ligands and two O atoms from two water molecules, forming a slightly distorted octahedral geometry. The ligand links the MgII centres into a three-dimensional network. Extensive N—H⋯O and O—H⋯O hydrogen bonds exist between the ligands and water molecules, stabilizing the crystal structure.

catena-Poly[[diaqua­calcium(II)]-bis­(μ-quinoline-3-carboxyl­ato)]

In the title complex, [Ca(C10H6NO2)2(H2O)2]n, the CaII ion is eight-coordinated by six carboxylate O atoms from four separate quinoline-3-carboxylate ligands, two of which are bidentate chelate and two bridging, and two water molecules in a distorted square-antiprismatic geometry. The bridging groups form a polymeric chain substructure extending along the c axis, the chains being connected by coordinated-water O—H⋯N and O—H⋯Ocarboxylate hydrogen bonds into a three-dimensional framework structure.

catena-Poly[[diaqua-strontium]-bis-(μ-quinoline-3-carboxyl-ato)].

The title compound, [Sr(C10H6NO2)2(H2O)2]n, contains an eight-coordinate SrII ion displaying a distorted square-antiprismatic geometry, two quinoline-3-carboxylate ligands and two terminal water molecules. The SrII atom is surrounded by six carboxylate O atoms from four separate quinoline-3-carboxylate ligands and two O atoms from two coordinated water molecules. The bridging carboxylate O atoms [Sr—O = 2.498 (3) and 2.495 (3) Å] link SrII atoms, forming a chain substructure extending along the c axis. The chains are linked by O—H⋯N and O—H⋯O hydrogen bonds, giving a three-dimensional framework structure

2-Ethyl-1H-imidazole-4-carboxyl-ate monohydrate.

In the title compound, C7H8N2O4·H2O, the imidazole N atom is protonated and one of the carboxylate groups is deprontonated, forming a zwitterion. The two carboxyl groups are are approximately coplanar with the imidazole ring [O—C—C—C torsion angles = −176.8 (2) and 2.9 (4)° for one group and −4.6 (3) and 176.4 (2)° for the other] and have an intramolecular O—H⋯O hydrogen bond between them. The water molecule is linked to the organic molecules via an N—H⋯O hydrogen bonds. Intermolecular O—H⋯O and N—H⋯O hydrogen bonds are found in the crystal structure.

Poly[diaquabis(μ-4-carboxy-2-propyl-1H-imidazole-5-carboxylato-κ3N3,O4:O5)calcium(II)]

In the title complex, [Ca(C8H9N2O4)2(H2O)2]n, the CaII atom is eight-coordinated in a distorted square-antiprismatic environment. The water-coordinated Ca atom is N,O-chelated by the monocarboxylate anion; the carboxyl –CO2 portion engaged in chelation bears an acid hydrogen. The free –CO2 portion engages in bonding to adjacent Ca atoms. The CaII centres are connected through the ligand, forming a layer structure; the layers are linked by hydrogen bonds into a three-dimensional network.

Poly[[aqua­(μ4-1H-benzimidazole-5,6-dicarboxyl­ato-κ4N3:O5:O5′:O6)(N,N-dimethyl­formamide-κO)cadmium(II)] dihydrate]

In the title compound, {[Cd(C9H4N2O4)(C3H7NO)(H2O)]·2H2O}n, the CdII atom is coordinated by one N atom and three O atoms from four different 1H-benzimidazole-5,6-dicarboxylate (Hbidc) ligands, one O atom from one dimethylformamide ligand, and one O atom from a water molecule in a distorted octahedral geometry. The Hbidc ligands connect the Cd atoms into a two-dimensional network parallel to (001). N—H⋯O and O—H⋯O hydrogen bonds involving the water molecules are observed in the crystal structure.

Poly[diaqua­bis(μ-4-carb­oxy-2-propyl-1H-imidazole-5-carboxyl­ato-κ3N3,O4:O5)calcium(II)]

In the title complex, [Ca(C8H9N2O4)2(H2O)2]n, the CaII atom is eight-coordinated in a distorted square-antiprismatic environment. The water-coordinated Ca atom is N,O-chelated by the monocarboxylate anion; the carboxyl –CO2 portion engaged in chelation bears an acid hydrogen. The free –CO2 portion engages in bonding to adjacent Ca atoms. The CaII centres are connected through the ligand, forming a layer structure; the layers are linked by hydrogen bonds into a three-dimensional network.