Yu. M. Korenev

Synthesis and structure of acetonitrile solvates of copper(II) monofluoroacetate and silver(I) trifluoroacetate, [Cu2(CH2FCOO)4·2CH 3CN](CH3CN) and Ag3(CF3COO)3(CH3CN)2

AbstractCompounds [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) (I) and Ag3(CF3COO)3(CH3CN)2(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, β = 106.82(3)°, V= 4292(2) Å3, Z= 8, R1= 0.0426; crystals IIare triclinic, space group

Two Modifications of Y2Piv6(Hpiv)6 crystals: Synthesis and structures

P\overline 1

Ab initio calculations of the structure, vibrational spectra, and thermodynamic properties of silver trifluoroacetates

, a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, α = 95.27(3), β = 109.59(3)°, γ = 104.60(3)°, V= 911.4(3) Å3, Z= 2, R1= 0.0252. Structure Iis composed of the structural units (“lanterns”) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.

Thermal decomposition of Cu(NO3)2.3H2O at reduced pressures

Abstract The Knudsen-effusion method has been used together with mass-spectrometric analysis of evaporation products to study (potassium fluoride+zirconium tetrafluoride) and (caesium fluoride+zirconium tetrafluoride). The molecules MZrF 5 , MZr 2 F 9 , and M 2 ZrF 6 were found in the gas phase and their partial pressures and enthalpies of dissociation were obtained. Activities of pure components were determined and tabulated at 1165 K. It has been shown that solid compound 3KF·ZrF 4 , which melts congruently at T = 1197 K, sublimes congruently only up to T = 1103 K.

Synthesis and X-Ray Structure of New Copper(II) Nitrates: Cu(NO3)2 · H2O and β-modification of Cu(NO3)2

Crystals of two modifications of yttrium pivalate solvate Y2Piv6(HPiv )6(HPiv = (CH3)3CCOOH) are synthesized and studied by single-crystal X-ray diffraction analysis. The 3α-modification crystallizes in the monoclinic system, a = 16.394(2) Å, b = 11.948(4) Å, c = 20.352(3) Å, β = 108.73(3)°, Z = 4, space group P21/n, R1 = 0.105. Crystals of the β-modifications are also monoclinic, a = 21.617(4) Å, b = 36.559(4) Å, c = 29.930(4) Å, β = 104.40(2)°, Z = 12, space group P21/c, R1 = 0.050. The molecular structures of crystals of the α-and β-modifications consist of the Y2(μ2-Piv)4(Piv)2(HPiv)6 dimers. The Y atoms with a distorted antiprismatic coordination surrounding of the O atoms (Y-O 2.23–2.53 Å) are linked by four bridging bidentate pivalate anions and form the structural fragment shaped into a distorted lantern. Monodentate Hpiv molecules participate in the formation of intramolecular hydrogen bonds with Piv ligands. Crystal structures of the α-and β-modifications differ in packing of the Y2Piv6(HPiv)6 dimers and in centrosymmetric nature of the dimers in the structure of the α-modification.

SYNTHESIS AND CRYSTAL STRUCTURE OF NEW AMMINECOPPER(II) NITRATES : CU(NH3)2(NO3)2 AND CU(NH3)(NO3)2

Single crystals of Mg pivalate hydrate, Mg(H2O)6(Piv)2 · 3H2O (HPiv = (CH3)3CCOOH) are synthesized and their structure is determined by X-ray diffraction method. The crystals are rhombic: a = 10.917(2) Å, b = 12.625(2) Å, c = 31.394(8) Å, Z = 8, space group Pbca, R1 = 0.0525. The Mg atom has octahedral surrounding of the O atoms of water molecules (Mg-O 2.044–2.137 Å). The cationic chains of [Mg(H2O)6]∞2+ lie in the voids of doubled network anionic layers of [(H2O)3(Piv)2]∞∞2−. Inside the layer, the pivalate anions alternate with water molecules in the xy plane, being bonded to them by hydrogen bonds. The cationic chains and the anionic layers are united into layered packs by hydrogen bonds between coordinated water molecules and pivalate anions and between coordinated and crystal hydrate water molecules.

Rare-earth(III) pivalates

Abstract The structure and properties of monomeric and dimeric silver trifluoroacetates were calculated at different levels of approximation, from RHF with the 3-21G basis set for all atoms to MP2 with the SBKJC and Stutrgart RSC relativistic effective core potentials for silver and the 6-311G (df) basis set for the other atoms. The monomer was found to exist as two conformers in the gas phase, in a more stable conformer, the Ag atom formed coordination bonds with two carboxyl oxygens, and a less stable conformer contained O–Ag–F bridges and the CO double bond. The CF3 group freely rotated in the monomer without Ag–F bonds and experienced hindered rotations in the dimer. The theoretically predicted vibrational spectrum of the dimer and the thermodynamic functions of the dimerization reaction were consistent with the available experimental data.