Modified polyoxometalates: Hydrothermal syntheses and crystal structures of three novel reduced and capped Keggin derivatives decorated by transition metal complexes

Three novel polyoxometalate derivatives decorated by transition metal complexes have been hydrothermally synthesized. Compound 1 consists of [(PMo6Mo2V8O44)-Mo-VI-V-V-O-IV{CO (2,2'-bipy)(2)(H2O)}(4)](3+) polyoxocations and [(PMo4Mo4V8O44)-Mo-IV-V-V-O-IV{Co(2,2'-bipy)(2)(H2O)}(2)](3-) polyoxoanions, which are both built on mixed-metal tetracapped [PMo8V8O44] subunits covalently bonded to four or two {Co(2,2'-bpy)(2)(H2O)}(2+), clusters via terminal oxo groups of the capping V atoms. Compound 2 is built on [(PMo8V6O42)-V-VI-O-IV{Cu-I(phen)}(2)](5-) clusters constructed from mixed-metal bicapped [(PMo8V6O42)-V-VI-O-IV](7-) subunits covalently bonded to two {Cu(phen)}(+) fragments in the similar way to 1. The structure of 3 is composed of [(PMo9Mo3O40)-Mo-VI-O-V](6-) units capped by two divalent Ni atoms via four bridging oxo groups.

Hydrothermal synthesis, structure, and characterization of two one-dimensional chainlike hybrid complexes [(CuX)(2)(o-phen)](infinity) (X = Br, Cl; o-phen = o-phenanthroline)

Two novel organic-inorganic hybrid complexes [(CuX)(2)(o-phen)](infinity) (X = Br (1), Cl (2); o-phen = o-phenanthroline) have been synthesized hydrothermally and characterized structurally by elemental analyses, IR, ESR, XPS spectrum, TG analyses and single-crystal X-ray diffraction. Both title compounds exhibit novel one-dimensional chainlike copper halide scaffolding constructed by the unusual [Cu3X3] hexagon motifs by sharing opposite edges, where a single Cu site of each [Cu3X3] hexagon is chelated with N donors of o-phen group. To our knowledge, such basic o-phen-copper halide skeleton has not been reported hitherto. Moreover, TG analyses indicate that both title compounds possess high thermal stability.

A two-dimensional molybdenum (V) phosphate with covalently bonded transition metal coordination complexes: hydrothermal synthesis and structure characterization of Na-2[{Mn(phen)(2)(H2O)}{Mn(phen)(2)}(3){Mn (Mo12O24)-O-V (HPO4)(6)(PO4)(2)(OH)(6)}] center dot 4H(2)O (phen=1,10-phenanthroline)

An organic-inorganic hybrid molybdenum phosphate, Na-2[{Mn(phen)(2)(H2O)} {Mn(phen)(2)}(3){(MnMo12O24)-O-v (HPO4)(6)(PO4)(2) (OH)(6)}] . 4H(2)O (phen=1,10-phenanthroline), involving molybdenum present in V oxidation state and covalently bonded transition metal coordination complexes, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a=16.581(l)Angstrom, b=18.354(1)Angstrom, c=24.485(2)Angstrom, alpha=80.589(l)degrees, beta=71.279(1)degrees, gamma=67.084(1)degrees, V=6493.8(8)Angstrom(3), Z=2, lambda(MoKalpha)=0.71073Angstrom (R(F)=0.0686 for 29,053 reflections). Data were collected on a Bruker Smart Apex CCD diffractometer at 293 K in the range of 1.76 < theta < 28.06degrees using omega-2theta scans technique. The structure of the title compound may be considered to be based on {Mo6O12(HPO4)(3)(PO4)(OH)(3)} units bonded together with {Mn(phen)(2)} subunits into a two-dimensional network. Two types of tunnels are observed in the solid of the title compound.

The synthesis and crystal structure of vanadium complexes: [(VO2)-O-IV(phen)(2)]center dot 6H(2)O and [2,2 '-(bipy)(2)(VO2)-O-V](H2BO3)center dot 3H(2)O

The organic-inorganic hybrid materials vanadium oxide [(VO2)-O-IV(phen)(2)](.)6H(2)O (1) and [(2,2'-bipy)(2)(VO2)-O-V](H2BO3)(.)3H(2)O (2) have been conventional and hydrothermal synthesized and characterized by single crystal X-ray diffraction, elemental analyses, respectively. Although the method and the ligand had been used in the syntheses of the compounds (1) and (2) are different, they almost possess similar structure. They all exhibit the distorted octahedral [VO2N4] unit with organonitrogen donors of the phen and 2,2'-bipy ligands, respectively, which coordinated directly to the vanadium oxide framework. And they are both non-mixed-valence complexes. But the compound (1) is isolated, and the compound (2) consists of a cation of [(2,2'-bipy)(2)(VO2)-O-V](+) and an anion of (H2BO3)(-). So the valence of vanadium of (1) and (2) are tetravalence and pentavalence, respectively. Meanwhile it is noteworthy that pi-pi stacking interaction between adjacent phen and 2,2'-bipy groups in compounds I and 2 also play a significant role in stabilization of the structure. Thus, the structure Of [(VO2)-O-IV(phen)(2)](.)6H(2)O and [(2,2'-bipy)(2)(VO2)-O-V](H2BO3)(.)3H(2)O are both further extended into interesting three-dimensional supramolecular.

Hydrothermal syntheses and crystal structures of bimetallic cluster complexes [{Cd(phen)(2)}(2)V4O12]center dot 5H(2)O and [Ni(phen)(3)](2)[V4O12]center dot 17.5H(2)O

The hydrothermal reactions of vanadium oxide starting materials with divalent transition metal cations in the presence of nitrogen donor chelating ligands yield the bimetallic cluster complexes with the formulae [{Cd(phen(2))(2)V4O12].5H(2)O (1) and [Ni(phen)(3)](2)[V4O12] . 17.5H(2)O (2). Crystal data: C48H52Cd2N8O22V4 (1), triclinic. P (1) over bar, a = 10.3366(10), b = 11.320(3), c = 13.268(3) Angstrom, alpha = 103.888(17)degrees, beta = 92.256(15)degrees, gamma = 107.444(14)degrees, Z = 1; C72H131N12Ni2O29.5V4 (2), triclinic. P (1) over bar, a = 12.305(3), b = 13.172(6), c = 15.133(4), alpha = 79.05(3)degrees, beta = 76.09(2)degrees, gamma = 74.66(3)degrees, Z = 1. Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.59degrees < theta < 26.02degrees and 2.01degrees < 0 < 25.01degrees using the omega-scan technique, respectively. The structure of 1 consists of a [V4O12](4-) cluster covalently attached to two {Cd(phen)(2)}(2+) fragments, in which the [V4O12](4-) cluster adopts a chair-like configuration. In the structure of 2, the [V4O12](4-) cluster is isolated. And the complex formed a layer structure via hydrogen bonds between the V4O12](4-) unit and crystallization water molecules.

Studies on the non-covalent complexes between oleanolic acid and cyclodextrins using electrospray ionization tandem mass spectrometry

Non-covalent inclusion complexes formed between an anti-inflammatory drug, oleanolic acid (OA), and alpha-, beta- and gamma-cyclodextrins (CDs) were investigated by means of solubility studies and electrospray ionization tandem mass spectrometry (ESI-MSn). The order of calculated association constants (K-1:1) of complexes between OA and different CDs in solution is in good agreement with the order of their relative peak intensities and the relative CID energies of the complexes under the same ESI-MSn conditions. These results indicate a direct correlation between the behaviors of solution- and gas-phase complexes. ESI-MS can thus be used to evaluate solution-phase non-covalent complexes successfully. The experimental results show that the most stable 1:1 inclusion complexes between three CDs and OA can be formed, but 2:1 CD-OA complexes can be formed with beta- and gamma-CDs. Multi-component complexes of alpha-CD-OA-beta-CD (1:1:1), alpha-CD-OA-gamma-CD (1:1:1) and beta-CD-OA-gamma-CD (1:1:1) were found in equimolar CD mixtures with excess OA. The formation of 2:1 and multi-component 1:1:1 non-covalent CD-OA complexes indicates that beta- and gamma-CD are able to form sandwich-type inclusion non-covalent complexes with OA. The above results can be partly supported by the relative sizes of OA and CD cavities by molecular modeling calculations.

Synthesis and characterization of ferrocene-terminated ruthenium phenylacetylide complexes with alligator clips

Ferrocene-terminated trans/Ru(dppm)(2) (dppm=Ph2PCH2PPh2)-contained molecular wires with alligator clips were prepared. They are suitable for self-assembly on gold electrode to investigate the influence of metal incorporation on the electron transportation property of the molecular wires.

High order liquid crystalline structure of poly(11-{[(4 '-heptyloxy-4-biphenylyl)carbonyl]oxy}-1-undecyne)

Liquid crystalline properties of a mesomorphic polyacetylene {-[HC=C(CH2 )(9)OOC-Biph-OC7H15](n)- (PA9EO7), Biph=4-4'-biphenylyl} are investigated by X-ray diffraction, polarizing optical microscope, and transmission electron microscope. Polyacetylene PA9EO7 from solution adopts a sandwich structure, which is a high order smectic phase. The biphenylyl pendants pack in a hexagonal fashion and the distance between two appendages is 4.51 Angstrom. The heptyloxy tails on one polymer backbone overlap with those on the neighboring chain. The nonyl spacer and the heptyloxy tail exhibit a hexagonal packing arrangement with intermolecular distance of 3.24 Angstrom.

The structural transition of DNA-Tris(1,10-phenanthroline) cobalt(III) complexes in ethanol-water solution

The interaction of DNA with Tris(1,10-phenanthroline) cobalt(III) was studied by means of atomic force microscopy. Changes in the morphologies of DNA complex in the presence of ethanol may well indicate the crucial role of electrostatic force in causing DNA condensation. With the increase of the concentration of ethanol, electrostatic interaction is enhanced corresponding to a lower dielectric constant. Counterions condense along the sugar phosphate backbone of DNA when e is lowered and the phosphate charge density can thus be neutralized to the level of DNA condensation. Electroanalytical measurement of DNA condensed with Co(phen)(3)(3+) in ethanol solution indicated that intercalating reaction remains existing. According to both the microscopic and spectroscopic results, it can be found that no secondary structure transition occurs upon DNA condensing. B-A conformation transition takes place at more than 60% ethanol solution.

Synthesis and structural characterization of organolanthanide complexes with 1,2-dicarba-closo-dodecaborane-1,2-dichalcogenolate ligands

Reactions of anhydrous LnCl(3) (Ln = Nd, Gd, Dy, Er, Yb) with 2 equiv of LiCp' in THF afford the lanthanocene complexes Of CP'(2)Ln(mu-Cl)(2)Li(THF)(2) (CP' = eta(5)-t-BuC5H4, Ln = Nd (1), Gd (2), Dy (3), Er (4), Yb (5); Cp'= 1,3-eta(5)-t-Bu2C5H3, Ln = Nd (6), Gd (7), Dy (8), Er (9), Yb (10)). The molecular structures of 7 and 8 were characterized by X-ray crystallographic analysis. In these complexes, two Cp' ring centroids and two it-bridging chloride atoms around the lanthanide atoms form a distorted tetrahedron. The insertion of elemental chalcogen E (E = S, Se) into Li-C bonds of dilithium o-carborane in THF solution afforded dimers of dilithium. dichalcogenolate carboranes, [(THF)(3)LiE2C2B10H10Li(THF)](2) (E = S (12a), Se (12b)), which were confirmed by a crystal structure analysis. Reactions Of Cp'(2)Ln(mu-Cl)(2)Li(THF)(2) (1-10) with 12a or 12b gave dinuclear complexes of the formula [Li(THF)(4)](2)[Cp'(2)LnE(2)C(2)B(10)H(10)](2) (Cp'= eta(5)-t-BuC5H4, E = S, Ln = Nd (13a), Gd (14a), Dy (15a), Er (16a), Yb (17a); E = Se, Ln = Nd (13b), Gd (14b), Dy (15b), Er (16b), Yb (17b); Cp'= 1,3-eta(5)-t-Bu2C5H3 E = S, Ln = Nd (18a), Gd (19a), Dy (20a), Er (21a), Yb (22a); E = Se, Ln = Nd (18b), Gd (19b), Dy (20b), Er (21b), Yb (22b)). According to the X-ray structure analyses, the dianions of 13a and 13b contain two o-carborane dichalcogenolate bridges, and each CP'2Ln fragment is attached to one terminal and two bridging chalcogen ligands. The central Ln(2)E(2) four-membered ring is not planar, and the direct metal-metal interaction is absent.

Novel bis(8-hydroxyquinoline)phenolato-aluminum complexes for organic light-emitting diodes

A novel series of emitting aluminum complexes containing two 8-hydroxyquinoline ligands (q) and a phenolato ligand (p) were synthesized and characterized. Double layer organic light-emitting diodes (OLEDs) were fabricated using these complexes as luminescent layers, and strong electroluminescence (EL) was observed. It was found that their emitting wavelengths were mainly determined by the first ligands (q). Cyclic voltammograms revealed a partially irreversible n-doping process and indicated that these complexes show excellent electron-transporting ability.

Correlation analysis of the structures and stability constants of gadolinium(III) complexes

To simplify the abstraction of descriptors, for the correlation analysis of the stability constants of gadolinium(III) complexes and their ligand structures, aiming at gadolinium(III) complexes, we only considered the ligands and ignored the common parts of the structures, i.e., the metal ions. Quantum-chemical descriptors and topological indices were calculated to describe the structures of the ligands. Multiple regression analysis and neural networks were applied to construct the models between the ligands and the stability constants of gadolinium(III) complexes and satisfactory results were obtained.

Crystal structure of 11-{[(4 '-heptoxy-4-biphenylyl) carbonyl]oxy}-1-undecyne

The crystal structure of 11-{[(4'-heptoxy-4-biphenylyl) carbonyl] oxy}-1-undecyne (A9EO7), an acetylene with a biphenyl mesogenic moiety, was studied by combination of electron diffraction (ED), wide-angle X-ray diffraction (WAXD), and molecular simulation of ED pattern and molecular packing. A9EO7 was found to adopt an orthorhombic P2(1)2(1)2 space group with cell parameters of a = 5.78 Angstrom, b = 7.46 Angstrom, and c = 63.26 Angstrom, for which molecular packing calculations were conducted to elucidate the molecular conformation. Its crystal morphology was observed using a transmission electron microscope (TEM) and an atom force microscope (AFM). A9EO7 crystal grew to form step like morphology. Crystallization behavior of A9EO7 in magnetic field was examined. Induced by magnetic field A9EO7 could crystallize in such a way that its molecular long axis was parallel to the substrate.

Synthesis and characterization of novel lanthanocene complexes with dichalcogenolate o-carboranyl ligands

Reactions of [ Cp(2)Ln(mu-Cl)](2) (Cp = eta(5)-C5H5, Ln = Nd, Yb, Dy, Gd, Er) with an equivalent of [ (THF)(3)LiE2C2B10H10Li. (TT-IF) (THF)](2) (E = S, Se) in THF afforded the dinuclear sandwich complexes of formula[Cp(2)LnE(2)C(2)B(10)H(10)](2)[Li(THF)(4)](2) [E = S, Ln = Nd (1a), Yb (2a), Dy (3a), Gd (4a), Er (5a); E = Se, Ln = Nd (1b), Yb (2b), Dy (3b), Gd (4b), Er (5b)]. The molecular structures of complexes la, 2a and 2b were determined by the single crystal X-ray structure analyses. Two lanthanide atoms are connected by a pair chalcogen (eta(1), eta(2)-E2C2B10H10) bridging ligands and the central Ln(2)E(2) four membered ring is not planar.