Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of the Synthetic Complex [Er(Pro)2(H2O)5]Cl3

Lv, Xue-Chuan; Liu, Beiping; Tan, Zhi‐Cheng; Li, Yansheng; Zhang, Zhiheng; Shi, Quan; Sun, Lixian; TaoZHANG,

doi:10.1021/je0505220

Cited by 6 publications

(5 citation statements)

References 14 publications

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“…The structure and principle of the adiabatic calorimeter have been described in detail elsewhere. − The automatic adiabatic calorimeter consisted of a sample cell made of gold-plated copper; a miniature platinum resistance thermometer (IPRT no. 2, produced by Shanghai Institute on Industrial Automatic Meters; 16 mm in length, 1.6 mm in diameter, and a nominal resistance of 100 Ω); an electric heater; the inner and outer adiabatic shields; two sets of six-junction chromel−constantan thermopiles, one installed between the calorimetric cell and the inner shield and the other between the inner and outer shields; and a high-vacuum can.…”

Section: Methodsmentioning

confidence: 99%

“…In the present investigation, a low-temperature adiabatic calorimeter for small samples, whose structure, working principle, and reliability have been described in our previous works, − was used to measure C p ,m for the title compound, Lu(C 2 H 5 O 2 N) 2 Cl 3 ·3H 2 O. The thermodynamic properties of the complex were studied using differential scanning calorimetry (DSC) and thermogravimetric and differential thermal analysis (TG−DTA).…”

Section: Introductionmentioning

confidence: 99%

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Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C₂H₅O₂N)₂Cl₃·3H₂O

Tan²,

Gao

2011

J. Chem. Eng. Data

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A complex of lutetium hydrochloric acid coordinated with 2-aminoacetic acid (C 2 H 5 O 2 N), Lu(C 2 H 5 O 2 N) 2 -Cl 3 3 3H 2 O, was synthesized. The molar heat capacities (C p,m ) and thermodynamic properties of the complex were studied with an automatic adiabatic calorimeter from (80 to 373) K. The thermodynamic functions [H T À H 298.15K ] and [S T À S 298.15K ] were derived over the temperature range from (85 to 315) K with a temperature interval of 5 K. The thermal decomposition behavior of the complex under a nitrogen atmosphere was studied by thermogravimetric analysis, differential thermal analysis, and differential scanning calorimetry. ' INTRODUCTIONRare-earth elements have many unique biochemical properties. With the great progress being made in cognition and research on the complexes of rare-earth ions with amino acids, the complexes have been used in many areas, such as fertilizers, pesticides, antibacterial agents, and so on. It is undoubtly the case that rare-earth elements would inevitably be spread into the bodies of beings with their applications. Therefore, it is necessary to obtain information about the long-term effects of rare-earth elements on people and explore more extensive applications of the complexes. Up to now, the complexes of lanthanide ions with amino acids have been synthesized and studied by a variety of methods. 1À5 However, only a few publications have dealt with the thermodynamic properties, 6,7 such as the molar heat capacity (C p,m ).The values of C p,m for a compound as a function of temperature are basic physical data. From these data, many other thermodynamic properties, such as enthalpy, entropy, and Gibbs free energy, can be calculated, 8 and these thermodynamic properties are important for both theoretical and practical purposes. Adiabatic calorimetry at temperatures from below 1 K to those approaching the limits imposed by the materials themselves 8 is a classical method for heat capacity measurements.In the present investigation, a low-temperature adiabatic calorimeter for small samples, whose structure, working principle, and reliability have been described in our previous works, 6À13 was used to measure C p,m for the title compound, Lu-(C 2 H 5 O 2 N) 2 Cl 3 3 3H 2 O. The thermodynamic properties of the complex were studied using differential scanning calorimetry (DSC) and thermogravimetric and differential thermal analysis (TGÀDTA).' EXPERIMENTAL SECTION Synthesis and Characterization of the Complex. Lu(C 2 H 5 -O 2 N) 2 Cl 3 3 3H 2 O was synthesized by a previously reported procedure. 14 The rare-earth oxide (Lu 2 O 3 ) was dissolved in an excess amount of hydrochloric acid, and the concentration of the solution was determined by EDTA titration analysis. Next, solid 2-aminoacetic acid (C 2 H 5 O 2 N) was added to the solution of Lu 3þ in a Lu 3þ :C 2 H 5 O 2 N molar ratio of 1:2. The pH of the reaction mixture was carefully adjusted to ∼2.5 by slow addition of NaOH solution. The mixture was stirred at 333 K in A water bath for (7 to 8) h. The solution...

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C₂H₅O₂N)₂Cl₃·3H₂O

Tan²,

Gao

2011

J. Chem. Eng. Data

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“…The calorimeter was established in the Thermochemistry Laboratory of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China. The principle and structure of the adiabatic calorimeter have been described in detail elsewhere. – …”

Section: Methodsmentioning

confidence: 99%

“…The principle and structure of the adiabatic calorimeter have been described in detail elsewhere. [11][12][13] To verify the accuracy of the calorimeter, the heat capacities of the reference standard material (R-Al 2 O 3 ) were measured over the temperature range 78 e (T/K) e 398. The sample mass used was 1.7143 g, which is equivalent to 0.0168 mol based on its molar mass, M(Al 2 O 3 ) ) 101.9613 g • mol -1 .…”

Section: Methodsmentioning

confidence: 99%

Thermodynamics of Sodium 5-Nitroisophthalic Acid Monohydrate

2010

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Low-temperature heat capacities of sodium 5-nitroisophthalic acid monohydrate (C8O6NH3Na2·H2O, s) were measured by a precision automated adiabatic calorimeter over the temperature range from (78 to 398) K. The experimental values of the molar heat capacities were fitted to a polynomial equation of heat capacities (C p,m) with the reduced temperatures (X), [X = f(T)], by a least-squares method. The smoothed molar heat capacities and thermodynamic functions of the compound (C8O6NH3Na2·H2O, s) were calculated on the basis of the fitted polynomial. The constant volume energy of combustion of the compound at T = 298.15 K was measured by a precise rotating-bomb combustion calorimeter to be Δc U = −(3969.41 ± 1.74) kJ·mol−1. The standard molar enthalpy of combustion of the compound was determined to be Δc H θ m = −(3965.07 ± 1.74) kJ·mol−1. The standard molar enthalpy of formation of the compound was calculated to be Δf H θ m (C8O6NH3Na2·H2O, s) = −(408.45 ± 2.03) kJ·mol−1 in accordance with Hess’s law. The standard molar enthalpy of solution of the compound, Δsol H θ m (C8O6NH3Na2·H2O, s), has been determined as (22.133 ± 0.111) kJ·mol−1. The standard molar enthalpy of the hydrated anion of the compound was determined as Δf H θ m (C8O6NH3 2−, aq) = (380.11 ± 2.04) kJ·mol−1, from the standard molar enthalpy of solution and other auxiliary thermodynamic data through a thermochemical cycle. The thermostability of the compound was investigated by thermogravimetric/differential thermogravimetric/differential scanning calorimetry (TG-DTG-DSC).

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“…A high-precision automatic adiabatic calorimeter that requires a small sample was used to measure the heat capacities in the temperature range from T = (78 to 400) K. The principle and design of the adiabatic calorimeter has been described in detail elsewhere. – Briefly, the calorimeter comprised a sample cell, a platinum resistance thermometer, an electric heater, inner and outer adiabatic shields, and a vacuum can. Two sets of six-junction chromel–constantan thermopiles are installed between the calorimetric cell and the inner shield and between the inner and outer shields, respectively.…”

Section: Methodsmentioning

confidence: 99%

Low-Temperature Heat Capacities and Standard Molar Enthalpy of Formation of l-3-(3,4-Dihydroxyphenyl) Alanine (C₉H₁₁NO₄)

Yang

Kong

et al. 2008

J. Chem. Eng. Data

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Low-temperature heat capacities of l-3-(3,4-dihydroxyphenyl) alanine (C9H11NO4) were measured by a precision automated adiabatic calorimeter over the temperature range from (78 to 400) K. A polynomial equation of heat capacities as a function of temperature was fitted by the least-squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at 5 K intervals. The constant-volume energy of combustion of the compound at T = 298.15 K was measured by a precision oxygen-bomb combustion calorimeter to be Δc U = −(21183.5 ± 35.0) J·g−1. The standard molar enthalpy of combustion of the compound was determined to be Δc H°m = −(4177.8 ± 6.9) kJ·mol−1, according to the definition of combustion enthalpy. Finally, the standard molar enthalpy of formation of the compound was calculated to be Δf H°m = −(935.9 ± 7.0) kJ·mol−1 in accordance with Hess law.

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Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of the Synthetic Complex [Er(Pro)₂(H₂O)₅]Cl₃

Cited by 6 publications

References 14 publications

Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C₂H₅O₂N)₂Cl₃·3H₂O

Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C₂H₅O₂N)₂Cl₃·3H₂O

Thermodynamics of Sodium 5-Nitroisophthalic Acid Monohydrate

Low-Temperature Heat Capacities and Standard Molar Enthalpy of Formation of l-3-(3,4-Dihydroxyphenyl) Alanine (C₉H₁₁NO₄)

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Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of the Synthetic Complex [Er(Pro)2(H2O)5]Cl3

Cited by 6 publications

References 14 publications

Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C2H5O2N)2Cl3·3H2O

Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C2H5O2N)2Cl3·3H2O

Thermodynamics of Sodium 5-Nitroisophthalic Acid Monohydrate

Low-Temperature Heat Capacities and Standard Molar Enthalpy of Formation of l-3-(3,4-Dihydroxyphenyl) Alanine (C9H11NO4)

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Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of the Synthetic Complex [Er(Pro)₂(H₂O)₅]Cl₃

Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C₂H₅O₂N)₂Cl₃·3H₂O

Molar Heat Capacities, Thermodynamic Properties, and Thermal Stability of Lu(C₂H₅O₂N)₂Cl₃·3H₂O

Low-Temperature Heat Capacities and Standard Molar Enthalpy of Formation of l-3-(3,4-Dihydroxyphenyl) Alanine (C₉H₁₁NO₄)