Shao-Wei Tong

Three new coordination frameworks based on 2-ethyl-imidazole-4,5-dicarboxylate and 1,10-phenanthroline: syntheses, crystal structures, and luminescence

Three new coordination polymers based on 2-ethyl-imidazole-4,5-dicarboxylate with 1,10-phenanthroline as ligands, Pb(HEIDC)(phen)2 (1), [Zn(EIDC)(phen)] n (2), and {[Ba(H2EIDC)2(phen)] · (phen)2 · [Ba(H2EIDC)(HEIDC)(phen)]} n (3) (H3EIDC = 2-ethyl-1-Himidazole-4,5-dicarboxylate; phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Complex 1 displays a tetranuclear square constructed of four Pb(II) centers, four HEIDC, and eight phen, resulting in a 3-D network with a 1-D open channel along the c-axis via C–H ··· O hydrogen bonds, C–H ··· π, and π–π stacking interactions. Complex 2 is an infinite zigzag chain resulting in the final 3-D supramolecular framework via C–H ··· O and π–π stacking interactions. Complex 3 is composed of two individual Ba chains, exhibiting a 3-D framework via O–H ··· O, O–H ··· N hydrogen bonds, and π–π stacking interactions. The photoluminescence spectra of 1 and 2 in the solid state have been investigated, 1 exhibits green photoluminescence in the solid state at room temperature.

Diaqua-bis-(5-carb-oxy-2-propyl-1H-imidazole-4-carboxyl-ato-κN,O)cadmium N,N-dimethyl-formamide disolvate.

In the title complex, [Cd(C8H9N2O4)2(H2O)2]·2C3H7NO, the six-coordinate CdII ion is in a slightly distorted octahedral environment, defined by two O atoms from two coordinated water molecules and two carboxylate O atoms and two N atoms from two N,O-bidentate 5-carboxy-2-propyl-1H-imidazole-4-carboxylate ligands. In the crystal, complex molecules and dimethylformamide solvent molecules are linked by O—H⋯O and N—H⋯O hydrogen bonds into a two-dimensional supramolecular structure. The propyl groups of the ligands are disordered over two conformations with refined occupancies of 0.680 (7) and 0.320 (7).

catena-Poly[(trans-diaqua­cadmium)-bis­{μ-5-[4-(1H-imidazol-1-yl)phen­yl]tetra­zol-1-ido}]

In the title compound, [Cd(C10H7N6)2(H2O)2], the CdII atom lies on an inversion centre and is coordinated by four N atoms from 5-[4-(1H-imidazol-1-yl)phenyl]tetrazol-1-ide ligands and two O atoms from the coordinated water molecules in an octahedral arrangement. The complex polymeric chains are interconnected via intermolecular water O—H⋯N hydrogen bonds into a three-dimensional network.

catena-Poly[(diaqua­strontium)-bis­{μ-5-[4-(1H-imidazol-1-yl)phen­yl]tetra­zolido}]

In the title complex polymer, [Sr(C10H7N6)2(H2O)2]n, the SrII atom lies on an inversion centre and is coordinated by four N atoms from two bidentate bridging trans-related 5-[4-(1H-imidazol-1-yl)phenyl]tetrazolide ligands [Sr—N = 2.387 (4) Å for the tetrazolide moiety and Sr—N = 2.273 (5) Å for the imidazole moiety], and by two O atoms from water molecules [Sr—O = 2.464 (4) Å], giving a distorted octahedral coordination. Pairs of ligand bridges link the complex units, forming chains which extend along [111] and are inter-associated through Owater—H⋯N hydrogen bonds, giving a two-dimensional network structure parallel to (001). Weak π–π stacking interactions between the benzene and imidazole rings are also present [minimum ring centroid separation = 3.691 (4) Å].

5-[4-(1H-Imidazol-1-yl)phen­yl]-1H-tetra­zole

In the title compound, C10H8N6, the tetrazole and benzene rings are close to being coplanar [dihedral angle = 9.90 (16)°], but the imidazole ring is rotated 37.18 (09)° out of the benzene plane. In the crystal, molecules are connected through tetrazole–imidazole N—H⋯N hydrogen bonds, giving rise to zigzag chains, which extend along [010].

5H-Imidazo[4,5-f][1,10]phenanthroline.

The title molecule, C13H8N4, is is essentially planar [r.m.s. deviation for all non-H atoms = 0.025 (3) Å]. In the crystal, molecules are connected through one weak bifurcated N—H⋯(N,N) hydrogen bond and three π–π stacking interactions between pyridine and imidazole rings [centroid–centroid distance = 3.631 (8) Å] and between pyridine and benzene rings [centroid–centroid distances = 3.675 (5) and 3.666 (2) Å].

Diaqua­bis­(5-carb­oxy-2-ethyl-1H-imidazole-4-carboxyl­ato-κ2N3,O4)cobalt(II) trihydrate

In the title compound, [Co(C7H7N2O4)2(H2O)2]·3H2O, the CoII cation, located on an inversion center, is N,O-chelated by two 5-carboxy-2-ethyl-1H-imidazole-4-carboxylate anions and further coordinated by two water molecules in a distorted octahedral geometry. Only one carboxy group of the anion is deprotonated, and the two carboxyl groups of the same anion are linked via an intramolecular O—H⋯O hydrogen bond. One of the lattice water molecules is located on an inversion center, its H atom equally disordered over two positions. One of H atoms of another lattice water molecules is also equally disordered over two sites. Water H atoms and the amino H atom all are involved in an intermolecular hydrogen-bonded network in the crystal.

Tetra­aqua­bis­[4-(1H-imidazol-1-yl-κN3)benzoato]cobalt(II)

In the title compound, [Co(C10H7N2O2)2(H2O)4], the CoII atom lies on an inversion centre and displays a slightly distorted octahedral geometry. The coordination sphere is defined by two mutually trans N atoms from two 4-(imidazol-1-yl)benzoate ligands and the O atoms from four water molecules. The crystal structure is stabilized by O—H⋯O hydrogen bonds.

3-Carb-oxy-5-(pyridinium-4-yl)benzoate: a redetermination.

The title compound, C13H9NO4, crystallizes in a zwitterionic form with the pyridine N atom protonated and the carboxyl OH group deprotonated. The benzene and pyridinium rings are inclined with a dihedral angle of 31.42 (14)° between them. A previous report of this stucture claims, we believe incorrectly, that neither of the carboxylate groups is deprotonated [Zhang et al. (2010 ▶). Acta Cryst. E66, o2928–o2928]. In the crystal, intermolecular O—H⋯O, N—H⋯O and weak C—H⋯O hydrogen-bonding interactions link adjacent molecules into a three-dimensional supramolecular network.

Diaqua-bis-(5-carb-oxy-2-propyl-1H-imidazole-4-carboxyl-ato-κN,O)cobalt(II) 3.5-hydrate.

In the title complex, [Co(C8H9N2O4)2(H2O)2]·3.5H2O, the CoII cation is six-coordinated by two H2pimda− ligands (H3pimda is 2-propyl-1H-imidazole-4,5-carboxylic acid) and two water molecules in a distorted octahedral environment. The crystal structures features a three-dimensional network stabilized by extensive O—H⋯O and N—H⋯O hydrogen bonds. The propyl groups of the ligands are disordered over two sets of sites with refined occupancies of 0.673 (8):0.327 (8) and 0.621 (17):0.379 (17). One of the water molecules is located on a site with half-occupancy.