Yang Liu

Syntheses, crystal structures and luminescence of zinc(II) and cadmium(II) complexes with 4′-substituted 2,2′:6′,2″-terpyridines

Four terpyridine coordination complexes, [Zn(meophtpy)2]·(ClO4)2·(H2O) (1), [Cd(meophtpy)2]·(ClO4)2 (2), [Zn(nh2phtpy)2]·(ClO4)2 (3), and [Cd(nh2phtpy)2]·(ClO4)2 (4) (meophtpy = 4′-(p-methoxylphenyl)-2,2′:6′,2″-terpyridine, nh2phtpy = 4′-aminophenyl-2,2′:6′,2″-terpyridine), were synthesized using the solvothermal method. These complexes have been characterized by IR spectra, elemental analyses, and X-ray diffraction. In all these complexes, the metal ions are coordinated by six nitrogens from two terpyridines. 3-D networks have been constructed by hydrogen bonds and π–π interactions. The luminescence of these four complexes has been investigated in the solid state at room temperature. Graphical abstract Four Zn(II) and Cd(II) complexes with two kinds of terpyridines have been synthesized and characterized. All these complexes are six N coordinated with two terpyridines. 3-D networks have been formed with hydrogen bonds and π–π interactions. The luminescence properties have been studied and all these ligands and complexes can be used as luminescence materials.

4,6-Dimethyl-pyrimidin-2-amine.

The asymmetric unit of the title compound, C6H9N3, contains three crystallographically independent molecules of similar geometry. All of the molecules are almost planar, with r.m.s. deviations of 0.003, 0.016 and 0.005 Å. In the crystal, the molecules are linked by N—H⋯N hydrogen bonds into zigzag ribbons parallel to the c axis, generating rings of R 2 2(8) graph-set motif.

Hydrothermal syntheses, crystal structures, and magnetic properties of three manganese(II) complexes based on 4′-substituted 2,2′:6′,2″-terpyridine ligands

Three manganese coordination compounds, [Mn(Meophtpy)2] · 2ClO4 (Meophtpy = 4′-(4-methoxylphenyl)-2,2′:6′,2″-terpyridine) (I), [Mn(Ftpy)2](ClO4)2 (Ftpy = 4′-(2-furyl)-2,2′:6′,2″-terpyridine) (II) and [Mn(m-ClPhtpy)2] · 2ClO4 (m-ClPhtpy = 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine) (III), have been synthesized by hydrothermal methods and characterized by IR, elemental analysis, powder and single-crystal X-ray diffraction analyses (CIF files CCDC nos. 945032 (I), 945033 (II), 945034 (III)). In most cases, the face-to-face interactions between pyridyl rings or phenyl rings facilitate the construction of 3D network in the crystal for all three complexes. The magnetic properties of three complexes have been investigated.

A new two-dimensional extended adenine and thiophenecarboxylate mixed-ligand zinc(II) complex: synthesis, structure, thermostability and luminescent properties.

The design and preparation of crystalline polymeric materials has attracted increasing attention due to their diverse applications as functional materials in gas storage, separation, catalysis, sensing and photoluminescence. The judicious selection of organic linkers is critical for varying the coordination behaviour of the metal ions and determining the overall characteristics of the networks. A new adenine-based Zn(II) coordination polymer, [Zn(C6H2O4S)(C5H5N5)]n or [Zn(tdc)(9H-ade)] (H2tdc is thiophene-2,5-dicarboxylic acid and ade is adenine), has been prepared hydrothermally and the crystal structure exhibits in its packing two-dimensional (4,4) grid sheets parallel to the ab plane, featuring two distinct square cavities delimited by the two types of ligands and the Zn(II) ions with the dimensions 6.6 × 6.6 and 10.2 × 10.2 Å (based on the Zn...Zn distance). The title complex shows enhanced photoluminescence at 378 nm compared to the free ligands, suggesting that the coordination of H2tdc or adenine to the metal centre effectively increases the rigidity of the ligands and reduces the energy loss by radiative decay of intraligand excited states.

Effect of solvent on the crystal structures of copper(II) complexes based on 4′-(4-methoxyphenyl)-2,2′:6′,2″-terpyridine and 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine

Four homoleptic copper(II) complexes, [Cu(Meophtpy)2](ClO4)2 (Meophtpy = 4′-(4-methoxylphenyl)- 2,2′:6′,2″-terpyridine) (I), [Cu(Meophtpy)2](ClO4)2 · 2H2O (II), [Cu2(m-Clphtpy)4](ClO4)4 (m-ClPhtpy = 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine) (III), and [Cu2(m-ClPhtpy)4](ClO4)4 (IV) have been synthesized by hydrothermal methods and characterized by IR, elemental analysis and single crystal X-ray diffraction (CIF files CCDC nos. 963375 (I), 885457 (II), 963377 (III), and 963376 (IV)). Complex II is a polymorph of I and complex IV is a polymorph of III. All these complexes are obtained with 95% ethanol solution or 50% ethanol solution and the solvent control on the crystallization are obviously found. In all complexes, the face-to-face interactions between pyridyl rings or phenyl rings facilitate the construction of 3D network in the crystal in addition to hydrogen bonds. The fluorescence properties of these complexes have been investigated.

A third polymorph of 1,4-bis­(1H-benzimid­azol-2-yl)benzene

The title compound, C20H14N4, is a new polymorph of the previously reported structures, which were orthorhombic, space group Pbca [Bei et al. (2000). Acta Cryst. C56, 718–719] and monoclinic, space group P21/c [Dudd et al. (2003). Green Chem. 5, 187–192]. The asymmetric unit consists of two independent molecules in which the dihedral angels between the central benzene ring and the outer benzimidazole ring systems are 16.81 (10) and 14.23 (10)° in one molecule and 26.09 (10) and 37.29 (10)° in the other. In the crystal, molecules are linked by N—H⋯N and C—H⋯N hydrogen bonds into a tape running along the c-axis direction.

Triaqua-1κO,2κ2O-bis­(2,2′-bipyridine)-1κ2N,N′;2κ2N,N′-chlorido-1κCl-μ-terephthalato-1:2κ2O1:O4-dicopper(II) nitrate monohydrate

In the binuclear title compound, [Cu2(C8H4O4)Cl(C10H8N2)2(H2O)3]NO3·H2O, the two crystallographically independent CuII ions have similar coordination environments. One of the CuII ions has a square-pyramidal arrangement, which is defined by a water molecule occupying the apical position, with the equatorial ligators consisting of two N atoms from a 2,2′-bipyridine molecule, one carboxylate O atom from a terephthalate ligand and one O atom from a water molecule. The other CuII ion has a similar coordination environment, except that the apical position is occupied by a chloride ligand instead of a water molecule. An O—H⋯O and O—H⋯Cl hydrogen-bonded three-dimensional network is formed between the components.