- Structures of anhydrous and hydrated copper(II) hexafluoroacetylacetonate
-
Crystal structure analyses are reported for anhydrous copper(II) hexafluoroacetylacetonate (Cu(hfac)2) and for two of its hydrates. The anhydrous compound (Cu(hfac)2, 1: P1; at 100 K, a = 5.428(1), b = 5.849(1), c = 11.516(3) A; α = 81.47(2), β = 74.57(2), γ = 86.96(2)°; Z = 1) contains centrosymmetric square-planar complexes with close intermolecular Cu···F contacts. The geometry of the complex is similar to that previously reported for Cu(hfac)2· toluene. The monoaquo compound (Cu(hfac)2(H2O), 2: P21/c; at 100 K, a = 10.8300(8), b = 6.5400(6), c = 21.551(3) A; β = 90.282(8)°; Z = 4) consists of square-pyramidal molecules with apical H2O ligands, and close-lying F atoms in the sixth coordination sites. The major difference between this structure and the two other polymorphs previously reported is the nature and direction of hydrogen bonds. The yellow-green solid formed from Cu(hfac)2 with excess H2O is identified as the trihydrate. In crystalline form it is the previously unreported [trans-Cu(hfac)2-(H2O)2] ·H2O (3: P1; at 150 K, a = 8.3899(3), b = 9.6011(3), c = 11.4852(4) A; α = 72.397(2), β = 79.161(2), γ = 87.843(2)°; Z = 2). There is no conclusive evidence in favor of any solid with the composition Cu(hfac)2· 2H2O.
- Maverick, Andrew W.,Fronczek, Frank R.,Maverick, Emily F.,Billodeaux, Damon R.,Cygan, Zuzanna T.,Isovitsch, Ralph A.
-
-
Read Online
- Design and preparation of hydrated MgAl supported Cu catalysts with high alkalinity by MOCVD for the hydrogenolysis of cellulose
-
The unhydrated and hydrated MgAl supported Cu catalysts were successfully prepared by metal-organic chemical vapor deposition (MOCVD) method. The structure properties of metal-organic precursor, supports and catalysts were determined by 1H NMR, FTIR, XRD, N2 physisorption, TEM, N2O titration, and CO2-TPD. The hydration of support had a significant effect on the structure of the final catalysts. The hydrated Mg3Al1 support was benefited to the adsorption and deposition of CuII(hfac)2, resulting in the decrease of the reduction decomposition temperature. Due to the restoration of the layered structure, the 5%Cu/H-Mg3Al1 catalyst had a low BET surface area and pore volume. However, it exhibited higher base sites density and got better performance for cellulose hydrogenolysis compared to the 5%Cu/Mg3Al1 catalyst, which suggested that the hydration before reaction was superior to that during reaction for the catalytic performance, due to the competition between water and products (alcohols with strong adsorption) during reaction, resulting in a decrease in the concentration of in-situ formed surface OH? and the amount of base sites. It was noteworthy that unobvious change in phases of the 5%Cu/H-Mg3Al1 catalyst was observed before and after reaction, which provided a promising way to establish the relationship between structure and catalytic performance.
- Xiao, Zihui
-
p. 343 - 349
(2017/06/19)
-
- Copper(II) complex with acetylacetone phenylhydrazone: Synthesis, crystal structure, and thermal stability
-
The Cu(phac)2 complex was synthesized by the reaction of copper(II) acetate with acetylacetone phenylhydrazone (Hphac), and its crystal structure was established by X-ray diffraction: space group P21/c, a = 11.173(3) ?, b = 8.267(2) ?, c = 12.633(4) ?, β = 115.01(3)°, V = 1057.5(5) ?3, Z = 4, R1 = 0.0476. The crystal structure of Cu(phac)2 consists of the centrosymmetrical mononuclear molecules. The central copper(II) ion is coordinated by two oxygen atoms and two nitrogen atoms of two acetylacetone phenylhydrazone ligands. The Cu(phac)2 molecules are linked in layers parallel to the Oyz plane. The oxygen atoms of the ketone fragment are involved in intermolecular bonding, which completes the coordination sphere of the central copper(II) ion to a substantially elongated octahedron. The thermal stability of the Cu(phac)2 complex was estimated under nitrogen at atmospheric pressure and in vacuo.
- Kuz'mina,Eliseeva,Balashov,Troyanov
-
p. 1182 - 1186
(2008/10/08)
-
- Crystal structure and vacuum sublimation of the product of reaction of yttrium hexafluoroacetylacetonate and copper acetylacetonate [Y(Hfa)3(H2O)2Cu(Acac)2]
-
The cocrystallization of an equimolar mixture of Y(Hfa)3 (Hfa = hexafluoroacetylacetonate ion) and Cu(Acac)2 (Acac = acetylacetonate ion) from 96% EtOH gives [Y(Hfa)3(H2O)2Cu(Acac)2] crystals with the following unit cell parameters: a = 12.435, b = 19.692, c = 16.242 A, β = 111.35°, V = 3704.2 A3, Z = 4, space group P21/c. In the [Y(Hfa)3(H2O)2] molecules (the structure was determined for the first time), the central Y3+ ion is coordinated by six oxygen atoms of three hexafluoroacetylacetonate ligands and two oxygen atoms of two H2O molecules. The Y-O(Hfa) bond lengths lie in the range 2.318-2.342 A (d(av) = 2.331 A) and are close to the Y-O(H2O) bond lengths of 2.342 and 2.346 A. The Cu(Acac)2 molecules in the crystals have the same structure as does the individual Cu(Acac)2 compound. In the crystal structure, the Y(Hfa)3(H2O)2 and Cu(Acac)2 molecules are linked together by intermolecular hydrogen bonds to form zigzag chains. Heating of [Y(Hfa)3(H2O)2Cu(Acac)2] in vacuum induces ligand-exchange reaction and evolution of Cu(Hfa)2 into the gas phase.
- Kuz'mina,Kupriyanova,Troyanov
-
p. 367 - 372
(2008/10/08)
-
