Chun-Hua Ge

Noncovalent interactions of pentafluorobenzoate in the Zn(II) and Cd(II) complexes

Abstract[Zn(Phen)2(Pfbz)(H2O)](Pfbz)(H2O)2 (I) and 2[Cd(Phen)2(Pfbz)(ONO2)][Cd(Phen)2(ONO2)2] (II) (Phen-1,10-phtnanthroline) containing the fluorine type ligand, pentafluorobenzoate (Pfbz) have been synthesized. Elemental analysis, IR spectra, and X-ray crystal structure analysis were carried out to determine the compositions and crystal structures of the two compounds. The crystal packing exhibits intricate intermolecular π-π stacking interactions and various hydrogen bonds. The C-H···F-C interactions and weak F···F interactions play important roles in the formation of the supramolecular network. Emission properties of I and II are also investigated.

Poly[[diaqua-μ4-tartrato-μ2-tartrato-dimanganese(II)] dihydrate]

In the title compound, {[Mn(C4H4O6)(H2O)]·H2O}n, the Mn2+ ion is connected to three different tartrate anions and a water molecule, resulting in a distorted MnO6 octahedral geometry. There are two tartrate half-anions in the asymmetric unit, both of which are completed by crystallographic twofold rotation symmetry. The tartrate dianions bridge the Mn2+ ions to form a wave-like infinite layer. A series of O—H⋯O hydrogen bonds link the layers into a three-dimensional network.

Aqua-(4,5-dihydroxy-benzene-1,3-disulfonato-κO)bis-(1,10-phenanthroline-κN,N')cadmium(II) monohydrate.

In the title compound, [Cd(C6H4O8S2)(C12H8N2)2(H2O)]·H2O, each CdII ion is coordinated by four N atoms [Cd—N = 2.310u2005(7)–2.341u2005(7)u2005Å] from two 1,10-phenanthroline ligands, one O atom [Cd—O = 2.300u2005(6)u2005Å] from a 4,5-dihydroxybenzene-1,3-disulfonate ligand and one aqua O atom [Cd—O = 2.288u2005(7)u2005Å] in a distorted octahedral geometry. The crystal packing exhibits intermolecular O—H⋯O and C—H⋯O hydrogen bonds and π–π interactions evidenced by relatively short distances [3.525u2005(5)–3.937u2005(6)u2005Å] between the centroids of the six-membered rings of neighbouring molecules.

Formation of a one-dimensional water chain containing two linking patterns of planar water tetramers.

The self-assembly of the title dinuclear complex, namely (mu-p-phenylenediamine-N,N,N,N-tetraacetato)bis[aqua(1,10-phenanthroline)nickel(II)] dodecahydrate, [Ni(2)(C(14)H(12)N(2)O(8))(C(12)H(8)N(2))(2)(H(2)O)(2)].12H(2)O, through intricate noncovalent interactions results in a two-dimensional sheet-like structure. The dimer lies about an inversion centre at the centre of the p-phenylenediamine ring. Uncoordinated water molecules form one-dimensional chains in which cyclic water tetramers act as two types of building blocks. The water molecules play a significant role in the stabilization of the three-dimensional supramolecular framework. Intramolecular ;aryl-metal chelate ring pi-pi interactions are also observed.

Manganese(II) and copper(II) complexes based on pentafluorobenzoate: interaction of fluorine in solid state

The synthesis and characterization of Mn(II) and Cu(II) complexes with the general formula [Mn(Phen)2(Pfbz)2](Hpfbz) (I) and [Cu2(Bipy)2(Pfbz)4] (II) (Phen = 1,10-phenanthroline, Bipy = 2,2′-bipyridine, Pfbz = pentafluorobenzoate) are reported. I crystallizes in triclinic crystal system, space group {tiP}1 with a = 9.755(1), b = 11.302(1), c = 20.064(2) Å, α = 95.799(2)°, β = 90.176(2)°, γ = 113.993(2)°, and Z = 2. Complex II crystallizes in triclinic crystal system, space group P1 with a = 9.661(1), b = 9.951(1), c = 12.891(1) Å, α = 102.943(2)°, β = 98.972(2)°, γ = 96.746(2)°, and Z = 1. Of particular interest, intricate C-H…F and F…F interactions in the two crystals play important role in the formation of three dimensional supramolecular networks. F(lp)…π (lp = lone pair) interaction is recognized in the solid-state structure of II.

Tetra-μ-acetato-bis{[N-(4-methyl­phen­yl)­pyridine-3-carboxamide]copper(II)} ethanol disolvate

The title compound, [Cu2(C2H3O2)4(C13H12N2O)2]·2C2H5OH, contains a centrosymmetric dinuclear copper(II) unit bridged by four acetate groups with two pyridine amide ligands occupying the axial positions. Each Cu atom is in a square-pyramidal coordination environment, and is displaced from the basal plane of the O atoms by 0.2071u2005(3)u2005A towards the pyridine nitroxadgen. The Cu⋯Cu separation is 2.6442u2005(5)u2005A. The amide groups of the ligands participate in the formation of interxadmolecular hydrogen bonds. Hydrogen bonds and π–π interxadactions between the pyridyl and benzene rings of neighbouring molxadecules [centroid-to-centroid distance 3.640u2005(4)u2005A] generate a two-dimensional supraxadmolecular network.

Ethyl [(n-butyl­ammonio)(2-hydroxy­phen­yl)meth­yl]phospho­nate

The title compound, C13H22NO4P, crystallizes as a zwitterion. The crystal packing exhibits N—H⋯O and O—H⋯O hydrogen bonds, leading to the formation of a three-dimensional supraxadmolecular network. Three C atoms, one in the nBu group and two in the Et group, are disordered over two positions; the site occupancy factors are ca. 0.8/0.2, 0.7/0.3 and 0.6/0.4.

Interaction between ligands in ternary complexes of cadmium(II) with phenanthroline and phenylalkylmalonates in solution

The formation and stability of the ternary complexes of cadmium(II) with phenanthroline and malonate, phenylmalonate, benzylmalonate, 2-phenylethylmalonate, and 3-phenylpropylmalonate are studied by the potentiometric pH-titration technique in 40% (v/v) dioxane-water at 25°C and 0.1 mol/l ionic strength (NaNO3). In all systems, there are stable ternary complexes. The complexes possess enhanced stability relative to their statistical values. The possible reasons that lead to these results are discussed in terms of π-electron back donation from metal ions to ligands and the intramolecular ligand-ligand aromatic ring stacking interaction. 1H NMR measurements are used to demonstrate the aromatic ring-stacking interaction. The relative contribution of each interactions to the enhanced stability is also estimated. The results show that there are two weak interactions simultaneously observed in these ternary complexes. The interaction strength of aromatic ring stacking in the ternary complexes increases in the phenylalkylmalonate ligand order: L0 < L1 < L2 ≈ L3 (L0 = phenylmalonate, L1 = benzylmalonate, L2 = 2-phenylethylmalonate, L3 = 3-phenylpropylmalonate).

cis-N,N-Bis(2-hy-droxy-benzyl-idene)cyclo-hexane-1,2-diamine.

In the title compound, C20H22N2O2, the cyclohexane ring adopts a chair conformation and the two N atoms bonded to salicylidene groups are in cis positions. Both hydroxy groups are involved in intramolecular O—H⋯N hydrogen bonding and the two benzene rings form a dihedral angle of 60.5u2005(1)°.

1,10-Phenanthrolinium 2,3,4,5,6-penta­fluoro­benzoate–2,3,4,5,6-penta­fluoro­benzoic acid (1/2)

In the title compound, C12H9N2 +·C7F5O2 −·2C7HF5O2, the cation and anion are linked by an N—H⋯O hydrogen bond. The neutral molecules bond to the anion via O—H⋯O hydrogen bonds to form associations of one cation, one anion and two neutral molecules. Intermolecular C—H⋯O, C—H⋯F, F⋯F [shortest contact = 2.768u2005(8)u2005Å], F⋯π [shortest contact = 3.148u2005(13)u2005Å] and π–π [shortest centroid–centroid separation = 3.689u2005(5)u2005Å] interactions further link the components to form a three-dimensional network.