Mehrkernige Oxo-Vanadium- und Oxo-Molybdän-Komplexe mit dem Dianion der Quadratsäure als Brückenligand. Strukturen von [C(NH2)3]4[V2O2F4(C4O4)2]·4H2O, [nBu4N]4[V3O3F4(C4O4)3]·2H2O, [Et4N]3[Mo3O8F(C4O4)2], [Et4N]4[Mo4O10F6(C4O4)] und [ Et4N]3[Mo2O3Cl3(C4O4)2] / Polynuclear Complexes of Oxo-Vanadium and Oxo-Molybdenum with the Dianion of Squaric Acid as Bridging Ligand. Crystal Structures of [C(NH2)3]4[V2O2F4(C4O4)2]·4H2O, [nBu4N]4[V3O3F4(C4O4)3]·2H2O, [Et4N]3[Mo3O8F(C4O4)2], [Et4N]4[Mo4O10F6(C4O4)] and [ Et4N]3[Mo2O3Cl3(C4O4)2]

1996 ◽  
Vol 51 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Martin Hilbers ◽  
Margita Meiwald ◽  
Rainer Mattes
Keyword(s):  
Squaric Acid ◽  
Polynuclear Complexes ◽  
X Ray Diffraction ◽  
Fluoride Ions ◽  
Metal Centers ◽  
X Ray ◽  
Bridging Ligand ◽  
Metal Atoms ◽  
Central Defect ◽  
Oxo Ligand

Abstract Aqueous or methanolic solutions containing vanadium(IV), molybdenum(V) and molyb-denum(VI) oxo species and fluoride ions react with squaric acid to give the oligonuclear complexes [C(NH2)3]4[V2O2F4(C4O4)2]·4H2O (1), Cs4[V3O3F4(C4O4)3]·5H2O (2a), [nBu4N]4[V3O3F4(C4O4)3]·2H2O (2b), [Et4N]4[Mo4O10F6(C4O4)] (3a), [Et4N]4[Mo4O10Cl6(C4O4)] (3b), [Et4N]3[Mo3O8F(C4O4)2] (4) and [Et4N]3[Mo2O3Cl3(C4O4)2] (5). The structures of compounds 1, 2a, 2b, 3a, 4 and 5 have been determined by single crystal X-ray diffraction. The [V2O2F4(C4O4)2]4- ion in 1 consists of the planar V2O2F4 core with the vanadium sites bridged by two ,μ-1,2-squarato ligands. The unique cone-shaped [V3O3F4(C4O4)3]4- ion in 2a and 2b contains a central defect and severely distorted V3F4 cubane unit. Each vanadium atom bears a terminal oxo ligand; pairs of vanadium atoms are bridged by μ-1,2-squarato ligands. The [Mo4O10F6(C4O4)]4- ion in 3a consists of a squarate ion, which is coordinated to four metal centers. Pairs of metal atoms are bridged by μ(O)μ(F)-bridges. Two terminal oxo ligands and one terminal fluoro ligand complete the metal coordination. Oxo and fluoro ligands are partly disordered. The structure of the [Mo3O8F(C4O4)2]3- ion in 4 is related to the structure of [V3O3F4(C4O4)3]4- It consists of a defect Mo3(O3F) cubane unit. Two pairs of molybdenum atoms are bridged by μ-1,2-squarato ligands. Terminal oxo and dioxo groups complete the molybdenum coordination. The [Mo2O3Cl3(C4O4)2]3- ion in 5 exhibits a unique structure with a planar OClMo(μ-O)(μ-Cl)MoOCl core and a cis, cis-orientation of the oxygen ligands. Two, μ-1,2-squarato ligands bridge the molybdenum centers above and below the Mo2O3Cl3 plane.

A Simple High-Yield Synthesis of Gallium(I) Tetrachlorogallate(III) and the Reaction of Digallium Tetrachloride Tetrahydrofuran Solvate with 1,2-Diols

2001 ◽  
Vol 56 (4-5) ◽  
pp. 337-341 ◽  
Author(s):  
Eva S. Schmidt ◽  
Annette Schier ◽  
Norbert W. Mitzel ◽  
Hubert Schmidbaur
Keyword(s):  
Crystalline Phase ◽  
Hydrogen Gas ◽  
High Yield ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Atoms ◽  
Gallium Hydride ◽  
Hydroxy Groups ◽  
Tetrahydrofuran Solution ◽  
Analogous Product

Abstract Gallium(I) tetrachlorogallate(III) Ga[GaCU] was prepared in quantitative yield by thermal de­composition of dichlorogallane [HGaCl2]2, which is readily available from Et3SiH and [GaCl3]2. The reaction of catechol with solutions of this gallium(I) tetrachlorogallate(III) in tetrahydrofuran leads to the evolution of hydrogen gas and affords a dinuclear gallium(III) complex with penta-coordinate metal atoms chelated and bridged by mono-deprotonated catechol ligands. In the crystalline phase tetrahydrofuran molecules are hydrogen-bonded to the hydroxy groups: [Ga(1,2 -OC6H4OH)Cl2(C4H8O)]2. The reaction with pinacol also gives hydrogen and the analogous product [Ga(OCMe2CMe2OH)Cl2(C4H8O)]2. The structures of the two compounds have been determined by X-ray diffraction. A mechanism of the new reaction has been proposed which involves oxidative addition of the diol to the solvate (THF)Cl2Ga-GaCl2(THF) present in the tetrahydrofuran solution to give a gallium hydride intermediate.

Tb2(bpdc)3 and Eu2(bpdc)3 Nanoparticles (bpdc: 2,2ʹ-Bipyridine-4,4ʹ- dicarboxylate) and Their Luminescence

2014 ◽  
Vol 69 (2) ◽  
pp. 248-254 ◽  
Author(s):  
Ana Kuzmanoski ◽  
Claus Feldmann
Keyword(s):  
Colloidal Stability ◽  
Aqueous Suspension ◽  
Earth Metal ◽  
Quantum Yields ◽  
X Ray Diffraction ◽  
Antenna Effect ◽  
Metal Centers ◽  
X Ray ◽  
Suspension Particle ◽  
Absolute Quantum

Tb2(bpdc)3 and Eu2(bpdc)3 nanoparticles (bpdc: 2,2ʹ-bipyridine-4,4ʹ-dicarboxylate) have been prepared via straightforward precipitation from aqueous solution. The nanoparticles exhibit mean diameters of 41(5) nm (Tb2(bpdc)3) and 56(4) nm (Eu2(bpdc)3) and show a very good colloidal stability in aqueous suspension. Particle size and chemical composition have been characterized based on electron microscopy, X-ray diffraction, infrared spectroscopy and thermogravimetry. Photoluminescence validates an efficient excitation of Tb3+/Eu3+ via the bpdc ligand as an antenna that leads to intense characteristic green and red emissions. The absolute quantum yields of Tb2(bpdc)3 and Eu2(bpdc)3 have been determined at 28 and 12%, respectively. Although rare-earth metal-based photoluminescence is typically quenched in water due to vibronic loss processes (v(O-H)), here, the antenna effect and the shielding of the metal centers via the bpdc ligand are very efficient, allowing for an intense green and red emission of the Tb2(bpdc)3 and Eu2(bpdc)3 nanoparticles even in aqueous suspension.

scholarly journals Tuning the Linear and Nonlinear Optical Properties of Pyrene-Pyridine Chromophores by Protonation and Complexation to d10 Metal Centers †

Inorganics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 38 ◽  
Author(s):  
Elena Lucenti ◽  
Alessandra Forni ◽  
Daniele Marinotto ◽  
Andrea Previtali ◽  
Stefania Righetto ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Second Harmonic ◽  
Protonated Form ◽  
Lewis Acidity ◽  
X Ray Diffraction ◽  
Metal Centers ◽  
X Ray ◽  
Nlo Response ◽  
D10 Metal ◽  
Simple Exposure

The linear and second-order nonlinear optical (NLO) properties of two pyrene-pyridine chromophores, namely, 4-(pyren-1-yl)pyridine (L1) and 4-(2-(pyren-1-yl)ethyl)pyridine (L2), were investigated and modulated by performing protonation/deprotonation cycles or by complexation to d10 metal centers such as Zn(II) and Cu(I) to form the monomeric [Zn(CH3CO2)2(L1)2] complex and the [CuI(L2)]n coordination polymer, respectively. The structures of L1, L2, [Zn(CH3CO2)2(L1)2] and [CuI(L2)]n were determined by means of single-crystal X-ray diffraction studies. The NLO response, measured by the electric-field-induced second harmonic generation (EFISH) technique, was positive for both chromophores and showed an inversion of the sign after exposure to HCl vapors. This process was completely reversible and the original values were restored by simple exposure to NH3 vapors. Coordination of L1 to Zn(II) also resulted in a negative NLO response, although smaller in magnitude compared to the protonated form, due to the weak Lewis acidity of the “Zn(CH3CO2)2” fragment. The results were also interpreted on the basis of DFT/TDDFT calculations.

A New Binuclear Lutetium(III) Dimethyl-N-trichloroacetylamidophosphate Complex with a γ, γ'-Dipyridyl Bridge, {Lu[CCl3C(O)NP(O)(OCH3)2]3}2-μ(γ,γ'-dipy)

2001 ◽  
Vol 56 (3) ◽  
pp. 249-254 ◽  
Author(s):  
Victor A. Trush ◽  
Jolanta Swiatek-Kozlowska ◽  
Victor V. Skopenko ◽  
Vladimir M. Amyrkhanov
Keyword(s):  
Crystal And Molecular Structure ◽  
Carbonyl Oxygen ◽  
Carbonyl Groups ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Metal Centers ◽  
X Ray ◽  
Heterocyclic Ligand ◽  
New Type ◽  
Ir Spectroscopic

Abstract A new type of binuclear coordination compound of lutetium, {Lu2L6 · μ-(γ,γ '-dipy)} (where L = dimethyl-N-trichloroacetylamidophosphate anion and γ,γ '-dipy = 4,4'-dipyridyl), has been obtained. The IR spectroscopic data reveal that the ambidentate phosphoryl ligand is coordinated to the metal center in a bidentate manner via the phosphoryl and carbonyl oxygen atoms. The crystal and molecular structure of {Ln2L6-μ-(γ ,γ '-dipy)} has been determined by means of X-ray diffraction (triclinic, space group P i with parameters: a = 9.259(2), b = 12.530(3), c = 16.548(3) Å, α = 85.44(3)°, β = 75.64(3)°, γ = 70.56(3)°, Z = 1). The structure is made up of centrosymmetric binuclear molecules, in which the neutral heterocyclic ligand is coordinated to the metal centers in a bidentate bridging manner via its nitrogen atoms. The coordination number of each Lu(III) atom is 7 [60(L-) + N((γ ,γ '-dipy)]. Phosphoryl and carbonyl groups of the L- ligands are disposed in syn-position and are included in the six-membered chelate metallocycles. The coordination polyhedron of lutetium can be described as distorted mono-capped octahedron.

The subatomic resolution study of laccase inhibition by chloride and fluoride anions using single-crystal serial crystallography: insights into the enzymatic reaction mechanism

2019 ◽  
Vol 75 (9) ◽  
pp. 804-816 ◽  
Author(s):  
Konstantin M. Polyakov ◽  
Sergei Gavryushov ◽  
Tatiana V. Fedorova ◽  
Olga A. Glazunova ◽  
Alexander N. Popov
Keyword(s):  
Molecular Oxygen ◽  
Enzymatic Reaction ◽  
Copper Ion ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Fluoride Ions ◽  
X Ray ◽  
Mechanism Of Inhibition ◽  
Wide Range ◽  
Oxygen Ligand

Laccases are enzymes that catalyze the oxidation of a wide range of organic and inorganic substrates accompanied by the reduction of molecular oxygen to water. Here, a subatomic resolution X-ray crystallographic study of the mechanism of inhibition of the laccase from the basidiomycete fungus Steccherinum murashkinskyi by chloride and fluoride ions is presented. Three series of X-ray diffraction data sets were collected with increasing doses of absorbed X-ray radiation from a native S. murashkinskyi laccase crystal and from crystals of complexes of the laccase with chloride and fluoride ions. The data for the native laccase crystal confirmed the previously deduced enzymatic mechanism of molecular oxygen reduction. The structures of the complexes allowed the localization of chloride and fluoride ions in the channel near the T2 copper ion. These ions replace the oxygen ligand of the T2 copper ion in this channel and can play the role of this ligand in the enzymatic reaction. As follows from analysis of the structures from the increasing dose series, the inhibition of laccases by chloride and fluoride anions can be explained by the fact that the binding of these negatively charged ions at the position of the oxygen ligand of the T2 copper ion impedes the reduction of the T2 copper ion.

Molecular Neodymium and Yttrium Cations with the N,N-Bis[2-(pyrid-2-yl)ethyl]hydroxylaminato Ligand

2010 ◽  
Vol 65 (10) ◽  
pp. 1279-1283
Author(s):  
Benjamin J. Hellmann ◽  
Hans-Georg Stammler ◽  
Norbert W. Mitzel
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Cationic Species ◽  
Metal Atoms ◽  
Three Component Reaction

The three component reaction of LnCp3, LnCp2Cl (Ln = Nd, Y) and N,N-bis[2-(pyrid-2- yl)ethyl]hydroxylamine [HON(C2H4-o-py)2] results in the formation of the [Nd(ON(C2H4-opy) 2)2]+[NdCp3Cl]− salt in the case of neodymium and the [Y(ON(C2H4-o-py)2)2]+[YCp2Cl2]− salt if yttrium is used in the synthesis. The N,N-bis[2-(pyrid-2-yl)ethyl]hydroxylaminato ligand is able to coordinate doubly to the metal atoms resulting in the formation of a cationic species. The compounds were characterised by X-ray diffraction experiments and additionally by CHN analyses in the case of the neodymium salt.

Syntheses, Structures, Thermal and Photoluminescence Properties of Two Zn(II) and Cd(II) Coordination Polymers Constructed from Taurine-derived Schiff Base and 4,4’-Bipyridine Ligands

2012 ◽  
Vol 67 (8) ◽  
pp. 774-782 ◽  
Author(s):  
Wei-Ting Guo ◽  
Zhi-Min Miao ◽  
Yun-Long Wang
Keyword(s):  
Schiff Base ◽  
Coordination Polymers ◽  
Tridentate Ligand ◽  
Supramolecular Architecture ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Monodentate Ligand ◽  
Metal Centers ◽  
X Ray ◽  
Ethanesulfonic Acid

Two chain-like coordination polymers, namely, {[Zn(saes)(4,4'-bipy)(H2O)]·H2O}n (1) and {[Cd (Hsaes)2(4,4'-bipy)(H2O)2]·2H2O}n (2), where H2saes=2-(2-hydroxybenzylideneamino)ethanesulfonic acid and 4,4'-bipy=4,4'-bipyridine, have been synthesized and characterized by singlecrystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric and photoluminescence analysis. X-Ray diffraction analyses indicate that 1and 2display octahedral metal centers with N3O3 and N2O4 donor sets, respectively. The Schiff base serves as a common N,O'-tridentate ligand in 1, and as a unique O-monodentate ligand in 2. In the crystal, both 1and 2form a 3D supramolecular architecture by O-H···O, C-H···O interactions or π···π stacking. The thermal and solid-state photoluminescence properties of both complexes have been investigated

The crystal structure of a dithiophosphate-bridged binuclear cobalt(II) complex of a macrocyclic ligand

1981 ◽  
Vol 34 (1) ◽  
pp. 65 ◽  
Author(s):  
GA Williams ◽  
R Robson
Keyword(s):  
Crystal And Molecular Structure ◽  
Macrocyclic Ligand ◽  
Cobalt Atom ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Axial Ligands ◽  
Octahedral Environment ◽  
Metal Atoms ◽  
A Cell

The crystal and molecular structure of LCO2 [S2P(OEt)2]2 (where L is a binucleating ligand derived from the macrocycle LH2 formed by condensation of two molecules each of propane-1,3-diamine and 2-hydroxy-5-methylisophthalaldehyde) has been determined by single-crystal X-ray diffraction techniques at 295 K. The compound crystallizes in the triclinic space group Pī with two molecules in a cell of dimensions a 18.644(6), b 11.694(4), c 9.487(4) �, α 84.99(3), β 82.61(3), γ 73.48(2)�. Automatic diffractometry has provided significant Bragg intensities for 2799 independent reflections and the structure has been refined by least-squares methods to R 0.054. The structure is molecular, consisting of discrete binuclear units LCo2[S2P(OEt)2]2. The two centrosymmetric molecules in the unit cell are crystallographically unique but essentially chemically similar. The two cobalt(11) atoms in each molecule are separated by 3.075(2) and 3.072(2) �. Each cobalt atom is in an octahedral environment, with an N2O2 equatorial plane and two sulfur atoms of bridging dithiophosphate ligands in the axial positions. The Co-S bonds are the longest yet observed [2,680(3), 2.652(3), 2.642(3), 2.623(3) �]. The cobalt(11) centres are high spin, with �eff 4.53 BM per cobalt atom. The macrocyclic ligand deviates slightly from planarity. The forces exerted both by the ligand L on associated metal atoms, and by axial ligands on the macrocycle, are discussed.

Adsorption of Fluoride Ions from Drinking Water Using Glass Derived Porous Hydroxyapatite Scaffolds

2013 ◽  
Vol 423-426 ◽  
pp. 1413-1417
Author(s):  
Dong Lin Gu ◽  
Wen Liang
Keyword(s):  
Borate Glass ◽  
Energy Dispersive Spectrometer ◽  
X Ray Diffraction ◽  
Polymer Foam ◽  
Fluoride Ions ◽  
Porous Hydroxyapatite ◽  
X Ray ◽  
Adsorption Performance ◽  
Sodium Calcium ◽  
Fluorine Ions

Sodium calcium borate glass derived hydroxyapatite (G-HAP) scaffolds were prepared by dipping with polymer foam. The effects of adsorption time and G-HAP scaffolds dosage on adsorption performance were studied. The results showed that G-HAP scaffolds could remove fluorine ions in solution effectively. The mechanism of G-HAP scaffolds in removing fluorine ions from aqueous solutions was investigated by the X-ray diffraction, Infrared Spectra and Scanning electron microscopy-Energy Dispersive Spectrometer.

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