- Production and Characterization of a New Copper(II) Propanoate-Isonicotinamide Adduct Obtained via Slow Evaporation and using Supercritical CO2 as an Antisolvent
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A new adduct of isonicotinamide (INA) with copper(II) propanoate [Cu(C3)2] was prepared [Cu2(C3)4(INA)4] using two different methods. This type of compound shows high fungicidal activity. Solvent evaporation from ethanol rendered crystals suitable for single-crystal X-ray diffraction. Furthermore, a new semicontinuous method capable of simultaneous crystallization and micronization of the adduct using supercritical CO2, the supercritical antisolvent technique (SAS), was also assessed. Crystals were characterized using powder X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis coupled with mass spectrometry, scanning electron microscopy, and microelemental analysis. In the adduct, two copper(II) ions are coordinated through two bridging and two chelating carboxylates to the propanoate anions forming approximately a plane. Each metal ion is then coordinated with the pyridine nitrogen of two different INA molecules that behave as monodentate ligands. The amide groups of the INA form H-bonds with other amide and carboxylate groups forming a molecular crystal with a three-dimensional H-bond arrangement of the binuclear units. With the SAS technique, crystals 100-fold smaller than those obtained by slow evaporation were obtained, proving SAS as a suitable method for mixed-ligand complexes preparation with reduced particle size and therefore expected bioavailability enhancement.
- Cuadra, Isaac A.,Martínez-Casado, Francisco J.,Cheda, José A. R.,Redondo,Pando, Concepción,Cabanas, Albertina
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p. 620 - 629
(2019/02/14)
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- Highly Regio- and Enantioselective Alkoxycarbonylative Amination of Terminal Allenes Catalyzed by a Spiroketal-Based Diphosphine/Pd(II) Complex
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An enantioselective alkoxycarbonylation-amination cascade process of terminal allenes with CO, methanol, and arylamines has been developed. It proceeds under mild conditions (room temperature, ambient pressure CO) via oxidative Pd(II) catalysis using an aromatic spiroketal-based diphosphine (SKP) as a chiral ligand and a Cu(II) salt as an oxidant and affords a wide range of α-methylene-β-arylamino acid esters (36 examples) in good yields with excellent enantioselectivity (up to 96% ee) and high regioselectivity (branched/linear > 92:8). Preliminary mechanistic studies suggested that the reaction is likely to proceed through alkoxycarbonylpalladation of the allene followed by an amination process. The synthetic utility of the protocol is showcased in the asymmetric construction of a cycloheptene-fused chiral β-lactam.
- Liu, Jiawang,Han, Zhaobin,Wang, Xiaoming,Wang, Zheng,Ding, Kuiling
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supporting information
p. 15346 - 15349
(2015/12/26)
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- Dual C-H activations of electron-deficient heteroarenes: Palladium-catalyzed oxidative cross coupling of thiazoles with azine N-oxides
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The palladium-catalyzed, copper-promoted cross-dehydrogenative-coupling (CDC) of electron-deficient thiazoles with azine N-oxides through dual C-H activations was developed. It was found that copper(II) pivalate was an efficient dual-function reagent for the oxidative cross-coupling reactions, playing the roles of both an oxidant and a C-H bond activation promoter. This methodology provides a simple way to construct 2-thiazolyl pyridine moiety.
- Fu, Xiao-Pu,Xuan, Qing-Qing,Liu, Li,Wang, Dong,Chen, Yong-Jun,Li, Chao-Jun
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p. 4436 - 4444
(2013/06/26)
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- Metal carboxylate salts
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A dietary source of mineral in the form of a metal carboxylate is prepared using the acid-base-like reaction. A salt of a carboxylate anion and a by-product cation is reacted in aqueous solution with a salt of a metal cation and a by-product anion under conditions which form a metal carboxylate and the by-product salt. Solutions formed in the reaction may be applied directly to a dry carrier to produce a dry dietary supplement or, alternatively, the solutions may be filtered to remove precipitated by-product salt and the filtrate used as a liquid dietary supplement. Preferably, a reducing agent, such as ascorbic acid, is added to help prevent the oxidation of divalent to trivalent form of a metal salt, when an easily oxidized divalent metal is used as starting material.
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Page/Page column 2
(2008/06/13)
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- One-dimensional and two-dimensional coordination polymers from self-assembling of trinuclear triangular cu(II) secondary building units
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The reactions of pyrazole (Hpz) with some copper(II) carboxylates in the presence of water yield trinuclear copper derivatives characterized by the triangular core [Cu3(μ3-OH)(μ-pz) 3(RCOO)2] (R = H, C2H5, C 3H7). Copper(II) formate gives [Cu3(μ 3-OH)(μ-pz)3(HCOO)2(Hpz)2] (1), whereas copper propionate and butyrate afford [Cu3(μ3- OH)(μ-pz)3-(C2H5COO)2(EtOH)] (2) and [Cu3(μ3-OH)(μ-pz)3(C 3H7COO)2(MeOH)(H2O)] (3), respectively, both containing solvent molecules coordinated to copper atoms. Magnetic susceptibilities are consistent with a single unpaired electron for each trinuclear unit of 1-3, and EPR measurements indicate that higher spin states, generated by exchange coupling between copper atoms, may be populated at room temperature. Density-functional calculations provide the description of the electronic structures of 1-3, allowing, at the same time, the assignment of their UV-vis absorption spectra. X-ray molecular structure determinations show that triangular trinuclear units of 1 are connected to each other through single formate bridges, forming one-dimensional (1D) zigzag coordination polymers, whereas in 2 and 3, two oxygen atoms of two carboxylate ions doubly bridge two copper atoms of different triangles, thus generating hexanuclear units. Moreover, in 2, two other propionate ions link together two hexanuclear units yielding a 12-membered cycle and giving rise to 1D coordination polymers. The supramolecular assemblies of 1-3 are compared to that of the previously reported trinuclear triangular copper(II) derivative [Cu3(μ3- OH)(μ-pz)3(CH3COO)2-(Hpz)] (A), where a two-dimensional (2D) coordination polymer is present. The reactions of 3,5-dimethylpyrazole (Hpz*) with copper(II) carboxylates in the same conditions yield 1:2 Cu(RCOO)2/Hpz* adducts.
- Casarin, Maurizio,Corvaja, Carlo,Di Nicola, Corrado,Falcomer, Daniele,Franco, Lorenzo,Monari, Magda,Pandolfo, Luciano,Pettinari, Claudio,Piccinelli, Fabio
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p. 6265 - 6276
(2008/10/09)
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- Decomposition of organic salts of some d and f metals: Non-isothermal kinetics and FT-IR studies
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The thermal decomposition in non-isothermal conditions of formates, acetates, propionates and butyrates of Mn, Co, Zn, Cd, Eu, Sm and Ni was studied. The observed compensation effect allows us to calculate the isokinetic temperature. A selective activation mechanism was suggested. This leads to a good agreement between kinetic and spectroscopic data.
- Vlase,Vlase,Chiriac,Doca
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p. 839 - 845
(2008/10/08)
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- Synthesis, characterization and molecular structures of homo- and heterometallic nickel(II) aminoalkoxides
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Soluble Ni(II) alkoxides, namely the dimethylaminoisopropoxide clathrate with toluene, Ni(η2-ORN)2· C7H8 (I) and the solvent free crystalline Ni(ORN)2(RN = CHMeCH2NMe2) species (II), obtained by sublimation of I in vacuo, were characterized by X-ray diffraction. The reaction between Ni(ORN)2 and copper carboxylates such as propionate and copper acetate hydrate in hydrocarbons afforded [CuNi2(O2CEt)3(ORN)3 (RNOH)] (III) and [Ni(Ni0.25Cu0.75)2(μ3-OH) (μ-OAc)(η1-OAc)2(μ,η2-OR N)2(η2-RNOH)] (IV), respectively. The structures of I and II are based on square planar molecules of the trans isomer. The structure of IV corresponds to triangular aggregates with a M3(μ3-OH) central core. The remarkable feature is the presence of three types of coordination sphere, one metal is coordinated octahedrally and corresponds to nickel and the other two have square pyramidal and square planar coordinations, respectively, and an electronic density corresponding to Cu (75%) and Ni (25%). The monodentate behavior of the two acetato ligands is stabilized by intramolecular hydrogen bonding involving the hydroxyl functionalities of the μ3-hydroxo (2.776(9) A?) and the solvated aminoalcohol ligand (2.573(6) A?). Magnetic data in the 20-300 K temperature range for III and IV account for three uncoupled metal centers at high temperature whereas ferromagnetic exchange interactions are likely below 20 K.
- Werndrup, Pia,Gohil, Suresh,Kessler, Vadim G.,Kritikos,Hubert-Pfalzgraf, Liliane G.
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p. 2163 - 2169
(2008/10/08)
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- THE DIRECT ELECTROCHEMICAL SYNTHESIS OF SOME TRANSITION METAL CARBOXYLATES
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The transition metal carboxylates M(O2CR)n (M=Cr, R=C2H5, C6H5, n=3; M=Mn, Fe, Ni, R=CH3, C2H5, C6H5, n-C7H15, n=2, not all combinations) have been prepared by oxidising suitable metal anodes electrochemically in solutions of RCOOH in acetonitrile.With Co and Cu, a wide range of carboxylic acids (R=C2H5, c-C3H5, c-C5H9, C6H5, n-C4H9, n-C7H15, 2-ethylhexanoic, oleic, linoleic) has been used succesfully to give M(O2CR)2.The advantages of the method are discussed.The preparation of Cu(O2CR)2 involves the prior formation of CuO2CR at the anode, followed by oxidation by the solvent.
- Kumar, N.,Tuck, Dennis G.,Watson, Katherine D.
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p. 740 - 743
(2007/10/02)
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- Structure-Magnetism Correlation in Dimeric Copper(II) Carboxylates: Crystal and Molecular Structure of Tetra-μ-(propanoato-O,O')-bis(aquacopper(II))
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The dimeric copper(II) carboxylates 2> and 2> (R=Et or Prn)) have been prepared and characterized by means of spectroscopic, magnetic, and thermogravimetric analyses.For 2> the crystal and molecular structure has also been determined.The crystals are monoclinic, space group P21/c, with a=15.102(7), b=17.186(5), c=15.190(4) Angstroem, β=94.24(3) deg, and Z=4.Full-matrix least-squares refinement, using 1784 independent reflections converged to a conventional R factor of 0.0561.The unit cell contains four crystallographically independent copper(II) atoms which give rise to three binuclear molecules with copper(II) acetate monohydrate type geometry.Two of these dimers are centrosymmetric with the symmetry centre at the middle of the Cu-Cu bond.Comparison of the present structural data and values with those of other structurally known dimeric copper(II) alkanoates does not allow an unambiguous determination of a specific ligand parameter to be the major factor in determining the magnitude of , and suggests that it may be the result of several modes of interaction.
- Battaglia, Luigi Pietro,Corradi, Anna Bonamartini,Menabue, Ledi
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p. 1653 - 1658
(2007/10/02)
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