A. L. Emelina

Synthesis, structure, physicochemical properties, and solid-phase thermolysis of Co2Sm(Piv)7(2,4-Lut)2

Heterometallic pivalate Co2Sm(Piv)7(2,4-Lut)2 (1) was prepared for the first time and structurally characterized at 293 and 160 K. Antiferromagnetic exchange interactions are dominant in complex 1. This compound experiences a first-order phase transition within 210–260 K. A set of thermodynamic functions was obtained for this complex (Cp, HT0 - H1800, and ST0), and parameters were determined for solid-phase thermolysis where samarium cobaltate SmCoO3 is the only product.

Heat capacity of LixNi2 − xO2 solid solutions

We have synthesized LixNi2 − xO2 oxides in the range x = 0.1–0.84 and showed that the solid-solution system contains a two-phase region. The heat capacity of LixNi2 − xO2 has been determined by differential scanning calorimetry.

Thermal behavior of samarium binuclear pivalate and tris-pivalate

Kinetic analysis of the thermolysis of samarium pivalate [Sm2(μ2-OOCCMe3)4(OOCCMe3)2(HOOCCMe3)6] · HOOCCMe3 (1) was carried out (the input data were differential scanning calorimetry (DSC) and thermogravimetry data), and a mathematic model of the process was developed that allowed us to optimize (by calculation) the conditions for formation of {Sm(OOCCMe3)3}n (2) samarium tris-pivalate via thermal decomposition of complex 1. The results of the thermal study of samarium and gadolinium tris-pivalates in the temperature range of −50…+50°C are reported. Specific anomalies were found in the DSC curves and heat capacity versus temperature curves in the temperature range of 0–50°C.

Thermodynamic properties of nonsuperconducting Ln2CuO4 (Ln = Nd, Sm, Eu), Ho2Cu2O5 and Ln2BaCuO5 (Ln = Nd, Sm, Eu, Ho, Yb) cuprates

Thermodynamic properties of rare-earth Ln2CuO4 (Ln = Nd, Sm, Eu), Ho2Cu2O5 and Ln2BaCuO5 (Ln = Nd, Sm, Eu, Ho, Yb) cuprates were determined using the electromotive force method with a fluorine-ion electrolyte in the temperature interval of 1000–1230 K. The thermodynamic data obtained by different experimental methods were compared.

Thermochemical properties of lithium cobaltate

Samples of low- and high-temperature modifications of LiCoO2 were produced and described. The heat capacity was measured by DSC in the temperature ranges of 140–570 and 180–570 K, respectively. The enthalpy and entropy of the cobaltates with respect to temperature were calculated from the data of heat capacity.

The thermodynamic properties of Ln2BaO4 (Ln = Sm, Dy, Ho)

The thermodynamic properties of the Ln2BaO4 phases (Ln = Dy, Ho, Sm) were studied by the electromotive force method with a fluoride electrolyte (890–1180 K), solution calorimetry in 1.07 N hydrochloric acid at 298.15 K, and differential scanning calorimetry (298–860 K). The experimental data were jointly processed, and the thermodynamic functions of the compounds over the temperature range 298–1200 K were calculated.

Thermodynamic properties of VTe2

The methods of adiabatic and differential scanning calorimetry are used to measure the temperature dependence of the heat capacity. Thermodynamic functions are calculated for VTe2. The Debye characteristic temperature is determined and the fractal dimension of crystalline vanadium ditelluride is calculated.

Synthesis and thermochemical characteristics of Na2O · Al2O3 · 2.5H2O

A pure phase of monosodium aluminate hydrate Na2O · Al2O3 · 2.5H2O (MAH) is synthesized and characterized by means of XRD, IR, SEM, TGA, and DSC. The heat capacity of the compound is measured in the temperature range of −100 to 100°C, and the thermal contributions to enthalpy and entropy are calculated. The standard entropy, enthalpy, and Gibbs energy of formation of MAH at 298 K are estimated.

Step-by-step thermal transformations of a new porous coordination polymer [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n} (Me{sub 2}mal{sup 2-}=dimethylmalonate): Thermal degradation to barium cuprate

Abstract The reactions of CuSO4·5H2O, dimethylmalonic acid and Ba(OH)2·H2O (Cu: H2Me2mal: Ba=1: 2: 2) in aqueous and aqueous-ethanol solutions (H2O: EtOH=1: 1) resulted in formation of 3D-porous coordination polymers [(H2O)3(μ-H2O)2CuBa(μ3-Me2mal)(Me2mal)]n (1) and [(μ-H2O)CuBa(μ3-Me2mal)(μ4-Me2mal)]n (2), respectively. It has been shown that compound 2 was an intermediate in the thermal degradation of compound 1. Thorough studies of solid-state thermolysis of 1 and 2 allowed to detect formation of coordination polymer [CuBa(μ4-Me2mal)(μ5-Me2mal)]n (3), structure of which was determined by X-ray powder diffraction. It has been found that the channels in polymer 3 were accessible for guest molecules (MeOH). Theoretical estimation of methanol diffusion barrier was carried out. Complete solid-phase thermolysis of 1 and 2 leads to a mixture of BaCuO2, BaCO3, and CuO. Special conditions for obtaining of a crystalline phase of pure cubic BaCuO2 were determined.