Thermochemistry of potassium morpholinodithiocarbamate

Results of thermochemical studies of a new compound, potassium morpholinodithiocarbamate, are presented. The enthalpies of its solution in water at various dilutions and the specific heat at 173–348 K were examined by the experimental methods of isothermal and dynamic calorimetry.     

Thermodynamic properties of ferrites of composition GdMIIFe2O5.5 (MII = Mg, Ca, Sr)

Ferrites with the composition GdM^IIFe₂O_5.5 (M^II = Mg, Ca, Sr) were synthesized from the corresponding oxides by the solid-phase method. The temperature dependence of the specific heat was studied by dynamic calorimetry in the temperature range 298.15 673 K. Equations describing this temperature dependence were derived. The temperature dependences of the thermodynamic functions were calculated.     

Thermodynamic Properties of Salsoline Salsolinodithiocarbamate

Heat of solution of salsoline salsolinodithiocarbamate (SS) at 1 : 18 000, 1 : 36 000, and 1 : 72 000 dilution (mol per mol H₂O) was determined on a DAK-I-IA calorimeter, and the standard heat of solution at infinite dilution was estimated. The temperature dependence of the heat capacity of SS was studied over the range 173–348 K. The heats of combustion and fusion, and the standard heat of formation of liquid (molten) and crystalline SS were estimated by indirect methods.     

Thermodynamic Properties of Nanosized Cobaltite (Nickelite) Cuprate Manganites LaMgCoCuMnO6 and LaMgNiCuMnO6

Russian Journal of Physical Chemistry A - The temperature dependences of the specific heat capacities of nanosized samples of lanthanum magnesium cobaltite cuprate manganite LaMgCoCuMnO6 and...     

Heat capacities and thermodynamic functions of new nanosized ferro-chromo-manganites LaM<Subscript>0.5</Subscript><Superscript>II</Superscript>FeCrMnO<Subscript>6.5</Subscript> (M<Superscript>II</Superscript>–Mg,Ca, Sr,Ba)

The heat capacities of nanosized ferro-chromo-manganites LaM_0.5 ^IIFeCrMnO_6.5 (M^II–Mg, Ca, Sr, Ba) are measured via dynamic calorimetry in the temperature range of 298.15–673 K using an IT-S-400 instrument. It is established that the C°_p~f(T) function of LaM_0.5 ^IIFeCrMnO_6.5 (M^II–Mg, Ca, Sr, Ba) has λ-type effects, due probably to phase transitions of the second order. Considering the temperatures of the phase transitions, equations of the heat capacity of ferro-chromo-manganites LaM_0.5 ^IIFeCrMnO_6.5 (M^II–Mg, Ca, Sr, Ba) as a function of temperature are derived on the basis of experimental data. Thermodynamic functions Н°(Т)–Н°(298.15), S°(Т), and Ф ^хх(Т) are calculated in the temperature range of 298.15–675 K.     

Thermochemistry of some cytisine derivatives

The enthalpies of solution of cytisine derivatives (phosphoric acid cytiside dimethyl ester, cytisinovinyloxyethylaminothiourea) in 96% ethanol at various dilutions were determined by isothermal calorimetry. Equations describing the dependences ΔH _s ⁰ = f(m ^1/2) (m is the molal concentration) were obtained. The standard enthalpies of solution, combustion, melting, and formation (at 298.15 K) of the compounds were calculated.     

Thermodynamic properties of alkaloids lappaconitine and glaucine

Calorimetric methods were used to study the enthalpy of solution of the alkaloids glaucine C₂₁H₂₅NO₄ and lappaconitine C₃₂H₄₄N₂O₈ in 96% ethanol and their heat capacity in the temperature ranges 173–298.15 and 173–423 K. Equations describing the dependences ΔH _sol ^m ～ f( $\sqrt m $ ) (m is molal concentration) and C _p ⁰ ～ f( $\sqrt T $ ) for the compounds under study were derived. The enthalpies of combustion, melting, and formation of C₂₁H₂₅NO₄ and C₃₂H₄₄N₂O₈ were estimated by means of theoretical calculations.     

Thermochemistry of Sesquiterpene Lactone 3,4β-Epoxyarglabin

The enthalpies of dissolution of 3,4β-epoxyarglabin C₁₅H₁₈O₄ are measured via isothermal calorimetry at lactone: 96% ethanol molar ratios of 1: 6000, 1: 12000, 1: 24000 at 298.15 K. The standard enthalpy of dissolution of C₁₅H₁₈O₄ in 96% ethanol is calculated from the obtained data; the value is 40.1 ± 0.4 kJ/mol. The enthalpies of combustion, melting, and formation of 3,4β-epoxyarglabin C₁₅H₁₈O₄ are estimated by approximate means.     

Synthesis and X-ray diffraction study of manganites LaM 3I M 3II Mn4O12(MI= Li, Na, K; MII = Mg, Ca)

Manganites LaM ₃ ^I M ₃ ^II Mn₄O₁₂(M^I = Li, Na, K; M^II = Mg, Ca) have been synthesized for the first time by the solid-phase reactions of lanthanum(III) and manganese(II) oxides and lithium, sodium, potassium, magnesium, and calcium carbonates. X-ray diffraction shows that all of them crystallize in the cubic crystal system. Their unit cell parameters are determined. Original Russian Text ? B.K. Kasenov, E.S. Mustafin, M.A. Akubaeva, Zh.I. Sagintaeva, S.T. Edil’baeva, Sh.B. Kasenova, S.Zh. Davrenbekov, Zh.S. Bekturganov, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 9, pp. 1433–1435.     

Manganites NdMg<Stack><Subscript>3</Subscript><Superscript>I</Superscript></Stack>Mg<Subscript>3</Subscript>Mn<Subscript>4</Subscript>O<Subscript>12</Subscript> (M<Superscript>I</Superscript> = Li,Na, K): X-ray diffraction data

NdLi₃Mg₃Mn₄O₁₂, NdNa₃Mg₃Mn₄O₁₂, and NdK₃Mg₃Mn₄O₁₂ manganites were synthesized for the first time by solid phase reactions of neodymium(III) and manganese(III) oxides with lithium, sodium, potassium, and magnesium carbonates. X-ray diffraction showed that the compounds crystallized in the tetragonal crystal system. Their unit cell parameters were determined.