Yifan Luo

Synthesis, crystal structure, and characterization of two lanthanide coordination polymers based on isonicotinate ligand

Two new europium complexes [Eu(inic)3(H2O)] (1) and [Eu(inic)3] (2) [inic = isonicotinate] have been structurally determined by single-crystal X-ray diffraction and characterized by elemental analysis, infrared spectroscopy, fluorescence, and thermogravimetric analysis. In the two complexes, bifunctional isonicotinate ligands interlink europium metal ions to construct 2-D (for 1) and 3-D (for 2) coordination polymeric networks.

4-(4-Pyrid­yl)pyridinium 3′,4,4′-tricarboxy­biphenyl-3-carboxyl­ate dihydrate

In the title compound, C10H9N2 +·C16H9O8 −·2H2O, both the cation and anion possess crystallographically imposed centres of symmetry, causing the nitrogen-bound H atom in the 4-(4-pyridyl)pyridinium cation and the acidic H atom of the carboxylate groups at the 3 and 3′ positions in the anion to be disordered over two positions with equal occupancies. In the crystal packing, the cations, anions and water molecules are connected by O—H⋯O, C—H⋯O and N—H⋯N hydrogen bonds, forming layers parallel to (20). These layer are further connected into a three-dimensional supramolecular network by O—H⋯O hydrogen bonds involving the water molecules as H-atom donors and by weak π–π stacking interactions between neighbouring benzene and pyridine rings, with centroid–centroid distances of 3.756 (5) Å.

4,4′-Bipyridinium bis(perchlorate)–4-aminobenzoic acid–4,4′-bipyridine–water (1/4/2/2)

In the structure of the title compound, C10H10N2 2+·2ClO4 −·4C7H7NO2·2C10H8N2·2H2O, the 4,4′-bipyridinium cation has a crystallographically imposed centre of symmetry. The cation is linked by N—H⋯N hydrogen bonds to adjacent 4,4′-bipyridine molecules, which in turn interact via O—H⋯N hydrogen bonds with 4-aminobenzoic acid molecules, forming chains running parallel to [30]. The chains are further connected into a three-dimensional network by N—H⋯O and O—H⋯O hydrogen-bonding interactions involving the perchlorate anion, the water molecules and the 4-aminobenzoic acid molecules. In addition, π–π stacking interactions with centroid–centroid distances ranging from 3.663 (6) to 3.695 (6) Å are present. The O atoms of the perchlorate anion are disordered over two sets of positions, with refined site occupancies of 0.724 (9) and 0.276 (9).

Poly[bis­(4,4′-bipyridine)(μ3-4,4′-dicarboxybiphenyl-3,3′-di­carboxyl­ato)iron(II)]

In the polymeric title complex, [Fe(C16H8O8)(C10H8N2)2]n, the iron(II) cation is coordinated by four O atoms from three different 4,4′-dicarboxybiphenyl-3,3′-dicarboxylate ligands and two N atoms from two 4,4′-bipyridine ligands in a distorted octahedral geometry. The 4,4′-dicarboxybiphenyl-3,3′-dicarboxylate ligands bridge adjacent cations, forming chains parallel to the c axis. The chains are further connected by intermolecular O—H⋯N hydrogen bonds, forming two-dimensional supramolecular layers parallel to (010).

Poly[(acetato-κ2O,O′)aqua­(μ4-1H-benzimidazole-5,6-dicarboxyl­ato-κ6N3:O5,O5′:O5,O6:O6′)cerium(III)]

In the title compound, [Ce(C9H4N2O4)(C2H3O2)(H2O)]n, the CeIII ion is coordinated by five O atoms and one N atom from four 1H-benzimidazole-5,6-dicarboxylato (L) ligands and by two O atoms from an acetate ligand and one aqua ligand, forming a slightly distorted tricapped trigonal–prismatic geometry. The L ligands are bridging, forming a layered polymer parallel to (010). In the crystal, O—H⋯O and N—H⋯O hydrogen bonds connect the polymer layers into a three-dimensional network.

Poly[(μ-1H-benzimidazole-5,6-dicarboxyl-ato)lead(II)].

The crystal structure of the two-dimensional polymeric title compound, [Pb(C9H4N2O4)]n, comprises one crystallographically independent PbII atom and one fully deprotonated 1H-benzimidazole-5,6-dicarboxylate (H2 L) ligand. The PbII atom is seven-coordinated by six O atoms and one N atom from the H2 L ligands, giving a capped octahedral coordination geometry. The structure is a layered two-dimensional coordination polymer extending parallel to (100) with N—H⋯O hydrogen bonds interactions between the layers, stabilizing the crystal structure.

Poly[(acetato-κO,O')aqua-(μ(4)-1H-benzimidazole-5,6-dicarboxyl-ato-κN:O,O:O,O:O)praseodymium(III)].

In the title complex, [Pr(C9H4N2O4)(C2H3O2)(H2O)]n, the PrIII ion is coordinated by five O atoms and one N atom from four benzimidazole-5,6-dicarboxylate ligands, two O atoms from an acetate ligand and one water molecule, giving a tricapped trigonal-prismatic geometry. The benzimidazole-5,6-dicarboxylate and acetate ligands connect the PrIII ions, forming a layer in the ac plane; the layers are further linked by N—H⋯O and O—H⋯O hydrogen bonding and π–π stacking interactions between neighboring pyridine rings [the centroid–centroid distance is 3.467 (1) Å], assembling a three-dimensional supramolecular network. The acetate methyl group is disordered over two positions with site-occupancy factors of 0.75 and 0.25.

Poly[(acetato-κ2O,O′)aqua­(μ4-1H-benzimidazole-5,6-dicarboxyl­ato-κ5N3:O5,O5′:O5,O6:O6′)praseodymium(III)]

In the title complex, [Pr(C9H4N2O4)(C2H3O2)(H2O)]n, the PrIII ion is coordinated by five O atoms and one N atom from four benzimidazole-5,6-dicarboxylate ligands, two O atoms from an acetate ligand and one water molecule, giving a tricapped trigonal-prismatic geometry. The benzimidazole-5,6-dicarboxylate and acetate ligands connect the PrIII ions, forming a layer in the ac plane; the layers are further linked by N—H⋯O and O—H⋯O hydrogen bonding and π–π stacking interactions between neighboring pyridine rings [the centroid–centroid distance is 3.467 (1) Å], assembling a three-dimensional supramolecular network. The acetate methyl group is disordered over two positions with site-occupancy factors of 0.75 and 0.25.

Poly[(acetato-κ2 O,O′)aqua­(μ4-1H-benzimidazole-5,6-dicarboxyl­ato-κ5 N 3:O 5,O 5′:O 5,O 6:O 6′)praseodymium(III)]

In the title complex, [Pr(C9H4N2O4)(C2H3O2)(H2O)]n, the PrIII ion is coordinated by five O atoms and one N atom from four benzimidazole-5,6-dicarboxylate ligands, two O atoms from an acetate ligand and one water molecule, giving a tricapped trigonal-prismatic geometry. The benzimidazole-5,6-dicarboxylate and acetate ligands connect the PrIII ions, forming a layer in the ac plane; the layers are further linked by N—H⋯O and O—H⋯O hydrogen bonding and π–π stacking interactions between neighboring pyridine rings [the centroid–centroid distance is 3.467 (1) Å], assembling a three-dimensional supramolecular network. The acetate methyl group is disordered over two positions with site-occupancy factors of 0.75 and 0.25.

Bis(2,2′-bipyridine)(2-hy­droxy-2,2-diphenyl­acetato)­copper(II) nitrate dihydrate

In the title complex, [Cu(C14H11O3)(C10H8N2)2]NO3·2H2O, the CuII atom is coordinated by four N atoms from two 2,2′-bipyridine ligands and two O atoms from one benzilate ligand in a distorted octahedral geometry. A supramolecular network is formed via intermolecular O—H⋯O and C—H⋯O hydrogen-bonding interactions. π–π stacking interactions between neighboring pyridine rings are also present, the centroid—centroid distance being 3.808 (2) Å.