Copper Trifluoroacetate Research Articles

Heterophase Synthesis of Silver Trifluoroacetate with Copper, Indium, and Zinc. Standard Enthalpy of Formation of Copper Trifluoroacetate

Heterophase Synthesis of Silver Trifluoroacetate with Copper, Indium, and Zinc. Standard Enthalpy of Formation of Copper Trifluoroacetate

Heterophase Synthesis of Silver Trifluoroacetate with Copper, Indium, and Zinc. Standard Enthalpy of Formation of Copper Trifluoroacetate

Solid-phase reactions of silver trifluoroacetate CF3COOAg with copper, indium, and zinc are studied by thermogravimetry, differential scanning calorimetry, and mass spectrometry. In a temperature range of 358–428 K, the reactions are found to afford trifluoroacetates of these metals without mass loss of the weighed samples. The obtained experimental data make it possible to calculate the enthalpy of formation of copper trifluoroacetate H298 (CF3СООСu, cr) = –1020.5 ± 18.0 kJ/mol.

Directing-Group-Assisted C(sp2)-H Arylsulfonylation from Sulfur Dioxide.

A straightforward and stereoselective preparation of (Z)-β-alkenyl sulfones through a reaction of N-tosyl acrylamides, 1,4-diazabicyclo[2.2.2]octane-sulfur dioxide, and aryldiazonium tetrafluoroborates under copper catalysis is accomplished. The direct C(sp2)-H arylsulfonylation of acrylamides using sulfur dioxide as the sulfonyl source in the presence of copper trifluoroacetate proceeds smoothly, giving rise to (Z)-β-alkenyl sulfones in good yields. During the reaction process, excellent regio- and stereoselectivities are observed.

Copper-Catalyzed 6-endo-dig O-Cyclization of 2-(But-3-en-1-yn-1-yl)benzamide

The copper-catalyzed synthesis of 3-vinylisocoumarin-1-imine is reported. The transformation proceeds smoothly with good yields in THF and the regioselectivity was determined by a O-nucleo­philic 6-endo cyclization. Studies on the mechanism indicate that copper trifluoroacetate serves as a Lewis acid, and the use of vinyl-connected 2-alkynylbenzamide is important for this O-nucleophilic 6-endo cyclization.

Interaction of copper with dinitrogen tetroxide in 1-butyl-3-methylimidazolium-based ionic liquids

Ionic liquids that are stable toward oxidation and nitration and are based on the 1-n-butyl-3-methylimidazolium cation (BMIm+) can be used as solvents and reaction media for copper dissolution in liquid dinitrogen tetraoxide N2O4. The ionic liquid not only favors the dissociation of N2O4 into NO+ and NO3-, but also takes part in the formation of different crystalline products. Thus, NO[BF4], NO[Cu(NO3)3] and (BMIm)2[Cu2(CF3COO)6] were prepared using (BMIm)A, A- = [BF4]-, (CF3SO2)2N-, CF3COO-, respectively. The formation of a certain product is determined by the nature of the anion A- and the relative solubility of the reaction products in the ionic liquid. Crystals of NO[BF4] were also prepared directly from a mixture of N2O4 and BMImBF4. According to XRD single-crystal structure analysis, the structure of NO[BF4] consists of tetrahedral [BF4]- anions and nitrosonium NO+ cations; the formation of these ions prove the heterolytic dissociation of N2O4 dissolved in the ionic liquid. The crystal structure of the earlier unknown binuclear copper trifluoroacetate (BMIm)2[Cu2(CF3COO)6] were determined by X-ray diffraction. The peculiarity of this dimer compared to the majority of known dimeric copper(ii) carboxylates is the unusually long CuCu distance (3.15 Å), with Cu(ii) ions demonstrating an atypical coordination of a distorted trigonal bipyramid formed by five O atoms of five trifluoroacetate groups.

Interaction between copper trifluoroacetate and quercetin in low-polarity organic media

(CF3COO)2Cu-Qr-P systems, where Qr is quercetin and P is ethyl acetate (EA), methyl methacrylate (MMA), or poly(methyl methacrylate) (PMMA), are studied using spectroscopic techniques. For ethyl acetate-based systems it is shown that the interaction between copper trifluoroacetate and quercetin in low-polarity organic media in the presence of excess salt gives rise to mixed-ligand complexes with Cu(II): Qr molar ratios of 1: 1 and 2: 1. The ranges of molar ratios of the reagents corresponding to the predominance of each species of the complex are determined. The stability constants of the complexes are calculated from the experimental data using the Bent-French and Benesi-Hildebrand methods. Optically transparent samples of poly(methyl methacrylate) modified with copper(II) compounds are prepared. Curing of the (CF3COO)2Cu-MMA and (CF3COO)2Cu-Qr-MMA systems by thermal casting polymerization of methyl methacrylate is shown to have an only negligible effect on their spectral properties.

ChemInform Abstract: Decarboxylative Trifluoromethylation of Aryl Halides Using Well‐Defined Copper—Trifluoroacetate and —Chlorodifluoroacetate Precursors.

ChemInformVolume 42, Issue 13 Isocyclic Compounds ChemInform Abstract: Decarboxylative Trifluoromethylation of Aryl Halides Using Well-Defined Copper—Trifluoroacetate and —Chlorodifluoroacetate Precursors. Kristen A. McReynolds, Kristen A. McReynolds Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorRobert S. Lewis, Robert S. Lewis Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorLaura K. G. Ackerman, Laura K. G. Ackerman Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorGalyna G. Dubinina, Galyna G. Dubinina Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorWilliam W. Brennessel, William W. Brennessel Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorDavid A. Vicic, David A. Vicic Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this author Kristen A. McReynolds, Kristen A. McReynolds Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorRobert S. Lewis, Robert S. Lewis Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorLaura K. G. Ackerman, Laura K. G. Ackerman Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorGalyna G. Dubinina, Galyna G. Dubinina Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorWilliam W. Brennessel, William W. Brennessel Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this authorDavid A. Vicic, David A. Vicic Dep. Chem., Univ. Hawaii, Honolulu, HI 96822, USASearch for more papers by this author First published: 03 March 2011 https://doi.org/10.1002/chin.201113044Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume42, Issue13March 29, 2011 RelatedInformation

Decarboxylative trifluoromethylation of aryl halides using well-defined copper–trifluoroacetate and –chlorodifluoroacetate precursors

New synthetic routes to (NHC)copper–trifluoroacetate and –chlorodifluoroacetate complexes were developed (NHC = N-heterocyclic carbenes) so baseline reactivity patterns could be established for the decarboxylative trifluoromethylation of organic halides. In the presence of aryl halides, loss of CO 2 from these new precursors occurred at 160 °C concurrent with the formation of aryl–CF 3.

Zr-doped YBCO Film Prepared by Fluorine-reduced MOD Method

Through replacing copper Tri-fluoroacetate by copper α-methacrylic in Metal Organic Deposition(MOD) process,the total amount of fluorine in YBCO precursor solution was reduced by about 50%.As a result,the calcination period for YBCO precurse film was dramatically reduced.The calcination time was reduced to 2h,only one seventh of that in all-Fluorine MOD process.X-ray diffraction and scanning electronic microscope(SEM) measurements show that YBCO films have strong YBCO(00l) peaks and crack-free surface.The critical temperture(Tc) and critical current density(Jc at self-field,77K) are 90K and 2.84MA/cm2,respectively.Furthermore,the property of YBCO film prepared by the fluorine-reduced MOD method is enhanced greatly by incorporating 6mol% Zr element into the film.

High-Field EPR and Magnetic Susceptibility Studies on Binuclear and Tetranuclear Copper Trifluoroacetate Complexes. X-ray Structure Determination of Three Tetranuclear Quinoline Adducts of Copper(II) Trifluoroacetate

Magnetic properties and high-field EPR spectra of three previously unknown tetranuclear quinoline adducts of copper(II) trifluoroacetate were studied, and their X-ray structures were determined. Two green complexes containing a mu(4)-oxo bridge, Cu(4)O(CF(3)COO)(6)(quin)(4) x (C(6)H(5)CH(3))(0.6) (orthorhombic, Pbca, a = 15.278(3), b = 23.227(5), c = 34.895(7) A) and Cu(4)O(CF(3)COO)(6)(quin)(4) x (C(6)H(6))(0.8) (monoclinic, P2/c, a = 21.933(4), b = 11.176(2), c = 23.927(5) A, beta = 97.41(3) degrees) are ferromagnetic, whereas the blue complex [Cu(4)(OH)(2)(CF(3)COO)(8)(quin)(2)](2-)(quinH(+))(2) (monoclinic, a = 21.933(4), b = 11.176(2), c = 23.927(5) A, beta = 97.41(3) degrees), formed in humid air from the solid dimeric [Cu(CF(3)COO)(2) x (quin)](2), is antiferromagnetic, as is the tetranuclear blue product formed in humid air of the mu(4)-oxo tetramers. High-field EPR spectra allowed determination of the spin Hamiltonian parameters for the spin quintet state (S = 2) in the ferromagnetic complexes, which facilitated accurate interpretation of their magnetic susceptibility data. "Broken symmetry" DFT calculations were performed to estimate the exchange integrals in all three tetranuclear complexes, showing surprisingly good agreement with experimental results. Negative sign of the zero-field splitting parameter D in two binuclear complexes, [Cu(CF(3)COO)(2) x CH(3)CN](2) and [Cu(CF(3)COO)(2) x (quin)](2), was found from single-crystal high-field EPR spectra, confirming recent results for nonhalogenated dimeric copper carboxylates.

Deposition and Characterization of Metal Propionate Derived Epitaxial ${\rm YBa}_{2}{\rm Cu}_{3}{\rm O}_{7-{\rm x}}$ Films for Coated Conductor Fabrication

A new modified TFA-MOD method for the YBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7-x</sub> (YBCO) deposition, using only barium trifluoroacetate, is presented. The yttrium and copper trifluoroacetates were replaced by the alcoholic solutions of Cu and Y acetates dispersed in propionic acid to prepare a stable coating solution. Due to the smaller amount of evolved hydrofluoric acid, this method permits the shortening of the pyrolysis time by a factor 4, with respect to conventional trifluoroacetate metal organic deposition (TFA-MOD) method. The X-ray photoelectron spectroscopy (XPS) analyses, performed on a pyrolyzed sample, showed the complete decomposition of precursors. The as obtained films exhibit good morphological, structural and superconducting properties with <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> (R = 0) greater than 90 K. Transport measurements at different temperatures and applied magnetic fields have revealed promising superconducting properties of the critical current density ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> ) vs. the applied magnetic fields and the value of <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> at 77 K and zero magnetic field greater than 3 MA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

Phase transformation analysis throughout an anhydrous fluorine based sol–gel YBCO processing route

This investigation has made use of four complementary chemical analysis techniques (differential thermal analysis, X-ray diffraction, Raman spectroscopy and UV–vis diffuse reflectance spectroscopy) to track the composition of an YBCO-TFA sol throughout the heat treatment cycle. From this, a schematic reaction pathway is proposed: below 400 °C, yttrium acetate transforms to yttrium trifluoroacetate and then to a yttrium intermediate (possibly yttrium(III) oxide, yttrium fluoride or yttrium oxyfluoride), barium acetate transforms to barium trifluoroacetate and then to barium fluoride, and copper acetate transforms to copper trifluoroacetate to copper(II) oxide. Above 400 °C the yttrium intermediate, barium fluoride and copper(II) oxide interact to form YBa 2Cu 3O 7− δ . The gelation reaction up to 170 °C may be monitored by measuring changes in diffuse reflectance at 395 nm, for example, using an LED/photodiode sensor as a component of an inline process control system.

The Interplay between Yttrium and Barium or Copper Trifluoroacetates and N‐Methyldiethanolamine: Synthesis of a Heterometallic Y3Cu Trifluoroacetate Complex and a Homometallic Ba‐TFA 1D Polymer

AbstractThe reactions between [Y(TFA)3(H2O)3] and either [Cu(TFA)2(MeOH)] or [Ba(TFA)2]∞ in the presence of excess N‐methyldiethanolamine (mdeaH2) have been investigated in relation with their use as precursors for high Tc superconductors. They afford the heterometallic Y3Cu complex [CuY3(μ3‐OH)(μ‐η3:η1‐mdeaH)3(μ3‐η3:η1:η1‐mdeaH)2(η2‐TFA)(μ,η2‐TFA)2](TFA)2(H2O) (1) and the homometallic Ba‐TFA 1D polymer [Ba3(η3‐mdeaH2)2(μ‐η3:η1‐mdeaH2)2(η1‐TFA)2(η2‐TFA)2(μ3‐η2:η2:η1‐TFA)2]1∞ (2), respectively, in high yield. These compounds were characterised by X‐ray diffraction and FT‐IR, ESR (for 1) and NMR (for 2) spectroscopy. Single‐crystal X‐ray diffraction studies show the versatile bonding modes of the trifluoroacetate and N‐methyldiethanolamine ligands, with the former acting not only as a terminal (η1 and η2) or bridging‐chelating (μ,η2 and μ3‐η2:η2:η1) ligand but also as a counterion, whereas the latter, either protonated or partially deprotonated, binds the metal centres in a chelating (η3) or bridging‐chelating (μ,η3:η1 and μ3‐η3:η1:η1) manner. The triangular Y3 unit [3.480(6)–3.550(6) Å] in the cation of 1 consists of one nine‐coordinate and two eight‐coordinate Y atoms, the former of which are quite scarce in alkoxide chemistry. The unique feature of the 1D polymeric structure of 2 is the secondary F···cation bond, which has not been observed so far for TFA ligands. In addition, it is the only example where the Ba atom is linked to monodentate, bidentate and bridging trifluoroacetate ligands simultaneously. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2007)

Photoelectron spectroscopic investigation of transformation of trifluoroacetate precursors into superconducting YBa2Cu3O7−δ films

X-ray photoelectron spectroscopy (XPS) has been used to investigate the evolution of surface chemistry of YBa2Cu3O7−δ (Y123) films prepared by the metalorganic deposition (MOD) process using trifluoroacetate (TFA) precursors. Detailed XPS core-level spectra obtained from the samples quenched from various points during the calcining and firing stages have been reported for the first time and are used to identify surface species. The XPS data show evidence of formation of intermediate phases such as Y–O–F, BaF2, and CuO during the calcining process, which are the decomposition products of yttrium, barium, and copper trifluoroacetates, respectively. The TFA precursors are completely decomposed at the end of calcination. The change of binding energies for Y 3d5/2, Ba 3d5/2, and O 1s during the firing process indicates that Y123 starts to form at 800°C after 0.5h firing. Based on the experimental results, an alternative mechanism of the chemical evolution from precursor to final film in the TFA-MOD process is proposed.

4,4′-Bipyrazolyl: new bitopic connector for construction of coordination networks

New organic bitopic connector 4,4′-bipyrazolyl ( bpz) easily forms complexes with metal ions and produces 1, 2 and 3D coordination polymers of different topology. Ten coordination polymers based upon bpz ligand and octahedral metal centers (Zn 2+, Cd 2+, Cu 2+, Co 2+) have been prepared and characterized by means of X-ray analysis. In all compounds the bipyrazolyl molecules act as bridging neutral groups and connect two metal atoms at the distances of 9.81–10.34 Å. Representative possibilities for the formation of multidimensional metal-organic array include linear chains in [Cu( bpz)(H 2O) 3(SO 4)]·H 2O, ‘ladder chains’ in [M( bpz) 1.5(H 2O) 2(NO 3)](NO 3) (M=Cu, Zn), flat and corrugated square grid layers in 1:2 complexes with cobalt chloride, zinc and cadmium perchlorates and copper trifluoroacetate, parallel/parallel interpenetrated square grid layers in [Cd( bpz) 2(NO 3) 2] and 3D diamondoid net in [Cu( bpz) 2(H 2O) 2](ClO 3) 2·5H 2O. With exception of the latter example the supramolecular architecture of metal-organic polymers may be clearly related with 4,4′-bipyridine derivatives, but more hydrophilic nature of pyrazole nuclei facilitates easy incorporation of different H-bond donors/acceptors—H 2O, CH 3OH, DMF. The 2D coordination arrays may enclathrate also guest molecules of hydrophilic aromatics that appear to be located between successive coordination layers: [Cu( bpz) 2(H 2O) 2](CF 3CO 2) 2·2H 2O·C 6H 5OH.

Syntheses and crystal structures of "unligated" copper(I) and copper(II) trifluoroacetates.

Two extremely unstable copper trifluoroacetates with no exogenous ligands, namely, Cu(O2CCF3) (1) and Cu(O2CCF3)2 (2), are prepared for the first time and obtained in crystalline form by deposition from the vapor phase. Their structures are determined by X-ray crystallography. The crystallographic parameters are as follows: for 1, monoclinic space group P2(1)/c, with a = 9.7937(6) A, b = 15.322(1) A, c = 12.002(1) A, beta = 106.493(9) degrees, and Z = 4; for 2, orthorhombic space group Pcca, with a = 16.911(1) A, b = 10.5063(9) A, c = 9.0357(6) A, and Z = 4. Both structures are unique among other CuI and CuII carboxylates, as well as among metal carboxylates in general. Compound 1 consists of a planar rhombus of four copper atoms with sides of 2.719(1)-2.833(1) A and trifluoroacetate ligands bridging the pairs of adjacent metal atoms alternately above and below the plane. The tetrameric units are further aggregated in a polymeric zigzag ribbon [Cu4(O2CCF3)4]infinity by virtue of intermolecular Cu...O contacts. The structure of 2 is built on cis bis-bridged dimers in which every metal atom is also connected with two copper atoms of the neighboring units. The stacking planes in this extended chain are almost perpendicular to one another. The Cu...Cu distance inside the dimer is 3.086(2) A, indicating a nonbonding interaction.

High TC Superconductor Fibers from Metallo-Organic Precursors

AbstractHomogeneous solution for Y-Ba-Cu-0 superconductor was prepared from yttrium i-propoxide, barium i-propoxide, and copper ethylhexanoate. The solution was converted to a resin-like material and was readily dissolved in organic solvents. The resin possesses a cohesive property in a number of solvents, such as benzene and xylene. Single-phase superconducting YBa2Cu307_x fibers have been continuously spun from the viscous solution. Controlled amounts of Y2BaCu05 phase in the fibers were made possible by slight adjustments in the solution compositions. Partial substitution of copper ethylhexanoate with copper trifluoroacetate prevents barium carbonate formation In the fiber during curing and organic pyrolysis.

Preparation and X-ray molecular structure of an unusal copper(I) polynuclear species: tetrakis(copper trifluoroacetate)dibenzene

The preparation, some of the reactions with olefins, and the crystal and molecular structure of a unique polynuclear CuI–benzene complex are reported: Cu4(F3CCO2)4·2C6H6.