Boron-nitrilotriacetate,N(CH2COO)3B: Synthesis and Crystal-Structure Determinations at 293K and 110K

The title compound is insoluble in aprotic solvents and decomposes in protic ones. Its crystal structure consists of discrete molecules with non-crystallographic C³⁰-symmetry and a transannular dative B? N bond (1.620(3) (Å). The molecules pack tightly (density 1.804 g cm^?2) interacting via O…C contacts between carbonyl groups (2.92–3.05 Å)). The atoms show small vibrational motion which may be interpreted in terms of a rigid body model. Distances and angles obtained at 293 and 110 were corrected for effects of rigid body motion and do not show significant differences.     

Syntheses and structural study of trinuclear iron acetates [Fe3O(CH3COO)6(H2O)3]Cl· 6H2O and [Fe3O(CH3COO)6(H2O)3] [FeCl4]· 2CH3COOH

The structure of two trinuclear iron acetates [Fe₃O(CH₃COO)₆(H₂O)₃]Cl· 6H₂O (I) and [Fe₃O(CH₃COO)₆(H_2O)₃][FeCl₄] · 2CH₃COOH (II) was determined by X-ray diffraction analysis. Crystals I and II are ionic and belong to the orthorhombic system with parameters a = 13.704(3), b = 23.332(5), c = 9.167(2) Å, R = 0.0355, space goup P2₁2₁2 for I and a = 10.145(4), b = 15.323(6), c = 22.999(8) Å, R = 0.0752, space group Pbc2₁ for II. The complex cation [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ has a μ₃-O-bridged structure typical for trinuclear iron (III) compounds. As shown by Mössbauer spectroscopy, the iron(III) ions are in the high-spin state. In trinuclear cations, antiferromagnetic exchange interaction takes place between the Fe(III) ions with the exchange parameter J = -26.69 cm^?1 for II (Heisenberg-Dirac-Van Vleck model for D_3h, symmetry).     

Wasserfreie Selten-Erd-Acetate,M(CH3COO)3 (M = Sm?Lu,Y) mit Kettenstruktur. Kristallstrukturen von Lu(CH3COO)3 und Ho(CH3COO)3

Anhydrous Rare-Earth Acetates, M(CH₃COO)₃ (M = Sm? Lu, Y) with Chain Structures. Crystal Structures of Lu(CH₃COO)₃ and Ho(CH₃COO)₃ Single crystals of the anhydrous rare-earth acetates containing lutetium (type 1) and holmium (type 2) were obtained by crystallisation at 120°C from diluted acetic acid solutions of their oxides and cesium acetate. The crystal structures [Lu(CH₃COO)₃: orthorhombic, a = 825.85(8), b = 1 398.1(2), c = 823.9(1) pm, V_m = 143.24(3) cm³/mol, space group Ccm2₁ (No. 36), Z = 4, R = 0.035, R_w = 0.030; Ho(CH₃COO)₃: monoclinic, a = 1 109.1(3), b = 2 916.3(10), c = 786.8(2) pm, β = 131.90(1)°, V_m = 142.58(8) cm³/mol, space group C2/c (No. 15), Z = 8, R = 0.039, R_w = 0.039, R_w = 0.026] were determined from four-circle diffractometer data sets. The structures consist of one-dimensional infinite chains built up by bridging acetate ions. Ho³⁺ is coordinated by 8 oxygen atoms, whereas Lu³⁺ has only 7 nearest oxygen neighbours. The chains are stacked parallel to the [001] direction. Isotypic compounds with Tm? Lu (type 1) and Sm? Er, Y (type 2) were prepared as powders and characterized by X-ray powder patterns. Thermoanalytical investigations (DTA, Guinier-Simon technique) of all compounds have shown that there is a first-order phase transition at 180°C (type 2) and in the range of 230–255°C (type 1). The high-temperature phase crystallizes with the known Sc(CH₃COO)₃ structure (type 0) where the rare earth cations are surrounded by 6 oxygen atoms. In the case of the type 1 compounds the phase transition is reversible.     

Synthese und Kristallstruktur von Praseodympropionat-trihydrat,Pr(CH3CH2COO)3(H2O)3

Synthesis and Crystal Structure of Praseodymium Propionate Trihydrate, Pr(CH₃CH₂COO)₃(H₂O)₃ Single crystals of Pr(CH₃CH₂COO)₃(H₂O)₃ were obtained by dissolving freshly prepared praseodymium hydroxide in diluted propionic acid. The crystal structure (monoclinic, P2₁/c, Z = 4, a = 1034.2(2) pm, b = 1521.2(3) pm, c = 2086.3(7) pm, β = 102.87(2)°, R1 = 0.0864, wR2 = 0.1196) consists of one-dimensional infinite chains parallel [010]. Pr1 and Pr2 are coordinated by four tridentate-bridging propionate groups. Additionally, Pr1 is coordinated by three “coordination water” molecules, Pr2 by two bidentate propionate groups. There are, in addition, three “crystal water” molecules so that praseodymium propionate trihydrate should be formulated as [(H₂O)₃Pr1(CH₃CH₂COO)₄Pr2(CH₃CH₂COO)₂] (H₂O)₃.     

Crystal structure of one of the strontium hydroacetates,Sr(H2O)2(CH3COO)2[H2(CH3COO)3]

All-Union Scientific-Research Institute for Chemical Reagents and Ultrapure Chemical Substances. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 1, pp. 104–108, January–February, 1988.     

Mössbauer spectroscopic and X-ray diffraction study of the thermal decomposition of Fe(CH3COO)2 and FeOH(CH3COO)2

Thermal decomposition of iron(II) acetate, Fe(CH₃COO)₂, and iron(III) acetate hydroxide, FeOH(CH₃COO)₂, has been studied using⁵⁷Fe Mössbauer spectroscopy and X-ray diffraction. Samples were thermally treated in air atmosphere between 150°C and 1000°C. The formation of maghemite '-Fe₂O₃, and hematite, -Fe₂O₃, is discussed. Hematite appears as the final decomposition product.     

Volumes of aqueous alcohols, ethers, and ketones to T = 523 K and p = 28 MPa.

Densities of dilute aqueous solutions of isopropanol, 1,5-pentanediol, cyclohexanol, benzyl alcohol, diethyl ether, 1,2-dimethoxyethane, acetone, and 2,5-hexanedione were measured by means of a vibrating-tube flow densimeter at temperatures near T = (302, 373, 423, 473, and 521) K at a pressure of p = 28 MPa. At the lowest and highest temperatures, measurements were also made close to the saturation vapour pressure of water to investigate the effect of pressure on the volumes of solutes. Apparent molar volumes were calculated for each solute and extrapolated to give partial molar volumes at infinite dilution. The variation of the volume with temperature, pressure, and structure of solute is discussed qualitatively, and group contributions are determined at the temperatures of measurements and p = 28 MPa. Several equations proposed in the literature for correlating the partial molar volumes at infinite dilution as a function of state parameters are tested. Parameters of one selected equation are tabulated allowing calculation of the partial molar volumes at infinite dilution at temperatures and pressures up to T = 573 K and p = 40 MPa. respectively.     

Photochemistry of cis,trans-[PtIV(en)(I)2(CH3COO)2] complex in aqueous solutions

Russian Chemical Bulletin - The photochemistry of aqueous solutions of the cis,trans-[PtIV(en)(I)2(CH3COO)2] complex (1) was studied by stationary photolysis, nanosecond laser flash photolysis and...     

Solid solutions in the Nd(CCl3COO)3-Sm(CCl3COO)3-H2O system at 298 K

The water-salt system of neodymium and samarium trichloroacetates, Nd(CCl₃COO)₃-Sm(CCl₃COO)₃-H₂O, has been investigated by the isothermal solubility method at 298 K. The composition of the solid phases is found by the Schreinemakers residues method. The refractive indices, specific volumes, and viscosities of the liquid phases and the refractive indices of the solid residues have been determined. Continuous solid solutions are found to form in the system. Some thermodynamic characteristics have been calculated for the solid solutions.     

Thermal decomposition of di-t-butyl peroxide in the presence of (CH3)2CCH2: Reactions of CH3, (CH3)2ĊCH2CH3, and (CH3)2ĊCH2C(CH3)2CH2CH3 radicals

A study of the reaction initiated by the thermal decomposition of di-t-butyl peroxide (DTBP) in the presence of (CH₃)₂C?CH₂ (B) at 391–444 K has yielded kinetic data on a number of reactions involving CH₃ (M·), (CH₃)₂CCH₂CH₃ (MB·) and (CH₃)₂?CH₂C(CH₃)₂CH₂CH₃ (MBB·) radicals. The cross-combination ratio for M· and MB· radicals, rate constants for the addition to B of M· and MB· radicals relative to those for their recombination reactions, and rate constants for the decomposition of DTBP, have been determined. The values are, respectively, where θ = RT ln 10 and the units are dm^3/2 mol^?1/2 s^?1/2 for k₂/k and k₉/k, s^?1 for k₀, and kJ mol^?1 for E. Various disproportionation-combination ratios involving M·, MB·, and MBB· radicals have been evaluated. The values obtained are: Δ₁(M·, MB·) = 0.79 ± 0.35, Δ₁(MB·, MB·) = 3.0 ± 1.0, Δ₁(MBB·, MB·) = 0.7 ± 0.4, Δ₁(M·, MBB·) = 4.1 ± 1.0, Δ₁(MB·, MBB·) = 6.2 ± 1.4, and Δ₁(MBB·, MBB·) = 3.9 ± 2.3, where Δ₁ refers to H-abstraction from the CH₃ group adjacent to the center of the second radical, yielding a 1-olefin. © 1994 John Wiley & Sons, Inc.     

Blue-luminescent/electroluminescent Zn(II) compounds of 7-azaindole and N-(2-pyridyl)-7-azaindole: Zn(7-azaindole)2(CH3COO)2, Zn(NPA)(CH3COO)2, and Zn(NPA)((S)-(+)-CH3CH2CH(CH3)COO)2 (NPA = N-(2-pyridyl)-7-azaindole)

A new 7-azaindole zinc(II) compound, Zn(7-azaindole)2(CH3COO)2 (1), a new ligand N-(2-pyridyl)-7-azaindole (NPA), and two NPA zinc(II) complexes, Zn(NPA)(CH3COO)2 (2) and Zn(NPA)((S)-(+)-CH3CH2CH(CH3)COO)2 (3), have been synthesized and structurally characterized. Compound 1 has a tetrahedral geometry, whereas compounds 2 and 3 have irregular six-coordinate geometry. The NPA ligand in compounds 2 and 3 functions as a bidentate chelate to the zinc center. Compound 1 has a blue luminescence in the solution and the solid state. Compounds 2 and 3 emit a blue color in the solid state. In solution, compounds 2 and 3 are fluxional, as established by 1H NMR experiments. Compound 1 is thermally stable, whereas compounds 2 and 3 undergo decomposition when heated in the solid state. A blue electroluminescent device using compound 1 as the emitting layer has been fabricated. Crystal data: NPA, monoclinic, P2(1)/c, a = 13.993(5) A, b = 8.456(3) A, c = 16.886(5) A, beta = 104.666(12) degrees, V = 1932.9(11) A3; 1, triclinic, P1, a = 9.5114(18) A, b = 10.460(7) A, c = 11.002(3) A, alpha = 117.18(3) degrees, beta = 103.287(18) degrees, gamma = 90.94(2) degrees, V = 938.3(7) A3; 2, monoclinic, C2/c, a = 13.234(6) A, b = 9.373(3) A, c = 13.956(7) A, beta = 113.24(3) degrees, V = 1590.7(12) A3; 3, monoclinic, P2(1), a = 11.047(7) A, b = 15.343(9) A, c = 13.785(8) A, beta = 100.123(9) degrees, V = 2300(2) A3.     

Metastable ion study of organosilicon compounds. Part XIV-trimethylsilylacetic acid, (CH(3))(3)SiCH(2)COOH, and its methyl ester, (CH(3))(3)SiCH(2)COOCH(3)

The unimolecular metastable decompositions of trimethylsilylacetic acid, (CH(3))(3)SiCH(2)COOH (1), and its methyl ester, (CH(3))(3)SiCH(2)COOCH(3) (2), were investigated by mass-analyzed ion kinetic energy (MIKE) spectrometry in conjunction with thermochemical data. The abundance of the molecular ions of both compounds, generated by electron ionization, is extremely low. However, the abundance of the ions generated by the loss of (.)CH(3) and observed at m/z 117 and 131 is moderate. These fragment ions further decompose to form the most abundant m/z 75 and 89 ions, respectively, by the loss of CH(2)CO through a (CH(3))(2)Si group migration. The loss of CH(2)CO is also observed to occur from 2(+.) and its fragment ion at m/z 115 generated by the loss of (.)OCH(3). The former reaction is proposed to occur via an ion-radical complex.     

Synthesis,crystal structure and thermal properties of Na2Ti(CF3COO)6(CF3COOH)2

The compound Na₂Ti(CF₃COO)₆(CF₃COOH)₂ was synthesized as colorless crystals, extremely unstable in air, by the reaction of TiCl₄ with trifluoroacetic acid and sodium trifluoroacetate. Crystallographic studies have shown that this sodium trifluoroacetatotitanate is the first example of a tetravalent titanium carboxylate [Ti(RCOO)₆]²– containing titanium in an octahedral environment of oxygen atoms of carboxylate groups. Thermal decomposition of Na₂Ti(CF₃COO)₆(CF₃COOH)₂ in an argon atmosphere results in the complex fluoride Na₂TiF₆.     

La(CCl3COO)3-LaCl3-H2O system at 298 K

The ternary water-salt system of lanthanum trichloroacetate and chloride was studied by the isothermal solubility method at 298 K. The compositions of the solid phases were determined by Schreinemakers’ method. The refractive indices, specific volumes, and viscosities of the liquid phase were found. The system was determined to be of the eutonic type.     

Kristallstruktur und Phasenumwandlung von Betain-Borat, (CH3)3NCH2COO·B(OH)3

Summary Betaine borate undergoes a phase transition of strongly second order at 142.5 K. Crystals below this temperature belong to the ferroelastic Aizu species mmmF2/m. The crystal structures of both phases have been determined. Paraelastic phase: Pmcn,a=7.769(1),b=9.873(2),c=11.974(2)Å,Z=4,T=293K,R=0.041 for 519 unique observed reflections. Ferroelastic phase: P2₁/c,a=7.615(5),b=9.872(3),c=11.947(5)Å, =92.98(8)°,Z=4,T=130K,R=0.083 for 507 unique observed reflections. In both structures the betaine molecules are connected to B(OH)₃-groups via hydrogen bonds to form chains running parallel[001]. These chains are associated to each other by van der Waals forces.

     

Ternäre Acetate der Lanthanide mit Caesium: Dimere und Trimere in CsLu(CH3COO)4 bzw. Cs2[Lu3(CH3COO)10(OH)(H2O)]. Synthese,Kristallstrukturen und Thermolyse

Ternary Acetates of the Lanthanides with Cesium: Dimers in CsLu(CH₃COO)₄ and Trimers in Cs₂[Lu₃(CH₃COO)₁₀(OH)(H₂O)]. Synthesis, Crystal Structures, Thermolysis Single crystals of CsLu(CH₃COO)₄ and Cs₂[Lu₃(CH₃COO)₁₀(OH)(H₂O)] were obtained from an aqueous solution of lutetium and cesium acetate in a 1:1 molar ratio. The crystal structures (CsLu(CH₃COO)₄: monoclinic, P2₁/n (no. 14), Z = 8, a = 1 293.1(2), b = 1 323.8(2), c = 1 622.5(3) pm, β = 92.01(2)°, V_m = 208.97(6) cm³/mol, R = 0.056, R_w = 0.034; Cs₂[Lu₃(CH₃COO)₁₀(OH)(H₂O)]: monoclinic, C2/c (no.15), Z = 4, a = 2 138.5(6), b = 1 378.0(3), C = 1 482.9(4) pm, β = 106.15(2)°, V_m = 632.0(3) cm³/mol, R = 0.049, R_w = 0.036) were determined from four-circle-diffractometer data. The structures consist of dimers and trimers, respectively, that are built by bridging acetate groups. These units are fragments of the infinite chains of the Ho(CH₃COO)₃ type of structure. The isotypic compounds CsM(CH₃COO)₄ with M=Eu? Lu were synthesized and characterized by the X-ray Guinier technique. The thermal decomposition of CsLu(CH₃COO)₄ was examined with thermoanalytical methods (TG/DSC with coupled gas analysis) and the Guinier-Simon technique: it decomposes at 260°C in an endothermic reaction to Lu₂O₃ and Cs₂CO₃.