Wen-Dong Song

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.

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.

Synthesis, crystal structure and third-order non-linear optical properties of a cobalt(II) one-dimensional supramolecular compound

A cobalt(II) thiocyanate complex [Co(py)4(NCS)2] 1 (py = pyridine) has been synthesized by low-temperature solid-state reaction. Single crystal X-ray analysis reveals that 1 possesses a one-dimensional (1-D) zigzag chain structure. Each Co ion is symmetrically coordinated by four pyridine ligands and also coordinates with two NCS− anions. Compound 1 was characterized by elemental analyses, IR spectra and UV-visible spectra. The third-order non-linear optical (NLO) properties were also investigated and they exhibit non-linear absorption and self-defocusing performance with modulus of the hyperpolarizability 9.46 × 10−30 esu for 1 in a 3.6 × 10−4 mol dm−3 DMF solution.

(5,5'-Dimethyl-2,2'-bipyridine-κN,N')(1-naphthyl-acetato-κO)(1-naphthyl-acetato-κO,O')zinc hemihydrate.

In the title compound, [Zn(C12H9O2)2(C12H12N2)]·0.5H2O, the water molecule lies on a twofold rotation axis. The ZnII atom is coordinated by three O atoms from two 1-naphthylacetate ligands, one monodentate and the other asymmetric bidentate chelate, and two N atoms from a 5,5′-dimethyl-2,2′-bipyridine ligand, giving an irregular environment. In the crystal, the complex molecules are interlinked through the water molecule by O—H⋯Ocarboxylate hydrogen bonds, together with weak C—H⋯O and bipyridine ring π–π stacking interactions [ring centroid separation = 3.761 (2) Å], giving a two-dimensional network structure.

Hydro(solvo)thermal synthesis and structural characterization of three lanthanide–carboxylate coordination polymers based on BDC and/or EDTA

Three lanthanide coordination polymers, [Ln4(BDC)6(H2O)2] n (Ln = Er, 1; Ln = Tm, 2; BDC = 1,2-benzenedicarboxylate) and {[Nd2(BDC)(EDTA)(H2O)2] · 1.5H2O} n , 3, were prepared by hydrothermal synthesis and characterized by elemental analysis, IR spectra, as well as single-crystal X-ray diffraction. The isostructural coordination polymers 1 and 2 exhibit four different coordination modes, which are rarely found in one lanthanide complex. Complex 3 displays a 2-D wave-like network assembled by two polycarboxylate ligands.

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

In the title complex, [Cu(C8H9N2O4)2(H2O)2]·2C3H7NO, the CuII ion, lying on an inversion center, is six-coordinated in a slightly distorted octahedral geometry. Two N atoms and two O atoms from two H2pimda (H3pimda is 2-propyl-1H-4,5-dicarboxylic acid) ligands are in the equatorial plane. The axial positions are occupied by two O atoms from two water molecules. A two-dimensional supramolecular network parallel to (001) is constructed by N—H⋯O and O—H⋯O hydrogen bonds. An intramolecular O—H⋯O hydrogen bond is also observed.

Pentaaqua(1H-benzimidazole-5,6-dicarboxylato-κN3)copper(II) pentahydrate

The title compound, [Cu(C9H4N2O4)(H2O)5]·5H2O, contains one crystallographically independent CuII atom and one 1H-benzimidazole-5,6-dicarboxylate (bdc) ligand, along with five coordinated and five uncoordinated water molecules. The CuII atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water molecules, giving an octahedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water molecules into a three-dimensional network.

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[[diaqua­(1,10-phenanthroline-κ2N,N′)nickel(II)]-μ-1H-benzimidazole-5,6-dicarboxyl­ato-κ2N3:O6]

In the title complex, [Ni(C9H4N2O4)(C12H8N2)(H2O)2]n, the NiII atom is hexacoordinated by one N and one O atom from two different 1H-benzimidazole-5,6-dicarboxylate ligands, two N atoms from one 1,10-phenanthroline ligand and two water molecules. The flexible 1H-benzimidazole-5,6-dicarboxylate ligands link the NiII centres, forming an infinite zigzag chain parallel to [001]. The crystal packing is governed by intermolecular hydrogen-bonding interactions of the O—H⋯O, N—H⋯O and C—H⋯O types.

μ-Aqua-κ2O:O-di-μ-4-methyl­benzoato-κ4O:O′-bis­[(4-methyl­benzoato-κO)(1,10-phenanthroline-κ2N,N′)nickel(II)]

In the title dinuclear complex, [Ni2(C8H7O2)4(C12H8N2)2(H2O)], each NiII atom is six-coordinated by three carboxylate O atoms from three 4-methylbenzoate ligands, two N atoms from two 1,10-phenanthroline ligands, and one μ2-bridging aqua ligand. The dimeric complex is located on a crystallographic twofold axis and each Ni atom displays a distorted octahedral coordination geometry. The crystal structure is stabilized via intramolecular hydrogen bonding of the bridging water molecule and the uncoordinated carboxylate O atoms, and by C—H⋯O and π–π stacking interactions [centroid–centroid distances between neighbouring phenanthroline ring systems and between the benzene ring of a 4-methylbenzoate unit and a phenanthroline ring system are 3.662 (2) and 3.611 (3) Å, respectively].