Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Low-temperature thermodynamic properties of dimeric tris(2,2,6,6-tetramethyl-3,5-heptanedionato) europium. / Bespyatov, M. A.; Cherniaikin, I. S.; Stabnikov, P. A. и др.
в: Journal of Chemical Thermodynamics, Том 140, 105904, 01.01.2020.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Low-temperature thermodynamic properties of dimeric tris(2,2,6,6-tetramethyl-3,5-heptanedionato) europium
AU - Bespyatov, M. A.
AU - Cherniaikin, I. S.
AU - Stabnikov, P. A.
AU - Tsygankova, A. R.
AU - Kuzin, T. M.
AU - Gelfond, N. V.
N1 - The reported study was funded by RFBR according to theresearch projectNo19-03-00385 and was supported by the Min-istry of Science and Education of the Russian Federation.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - A sample of dimeric tris(2,2,6,6-tetramethyl-3,5-heptanedionato) europium ([Eu(C11H19O2)3]2 or dipivaloylmethanate europium) was synthesized. Chemical analysis, elemental analysis and X-ray crystallography were used to characterize composition and structure of the complex. Low-temperature heat capacity of the sample was measured by adiabatic method in a temperature range from 8.63 K to 312.90 K. The Debye temperature at 0 K was calculated. Thermodynamic functions (entropy, enthalpy, reduced Gibbs energy) in a range (0–312) K have been calculated using the obtained experimental heat capacity data. An anomaly in the functional behaviour of heat capacity was detected in a temperature range from 250 K to 270 K, with a maximum at Tc = (262.36 ± 0.01) K. A reversible colour change (thermochromism) of europium dipivaloylmethanate crystals upon cooling below 245 K was detected. Anomalous contributions to entropy and enthalpy have been revealed. The nature of the effects detected is discussed.
AB - A sample of dimeric tris(2,2,6,6-tetramethyl-3,5-heptanedionato) europium ([Eu(C11H19O2)3]2 or dipivaloylmethanate europium) was synthesized. Chemical analysis, elemental analysis and X-ray crystallography were used to characterize composition and structure of the complex. Low-temperature heat capacity of the sample was measured by adiabatic method in a temperature range from 8.63 K to 312.90 K. The Debye temperature at 0 K was calculated. Thermodynamic functions (entropy, enthalpy, reduced Gibbs energy) in a range (0–312) K have been calculated using the obtained experimental heat capacity data. An anomaly in the functional behaviour of heat capacity was detected in a temperature range from 250 K to 270 K, with a maximum at Tc = (262.36 ± 0.01) K. A reversible colour change (thermochromism) of europium dipivaloylmethanate crystals upon cooling below 245 K was detected. Anomalous contributions to entropy and enthalpy have been revealed. The nature of the effects detected is discussed.
KW - Adiabatic calorimetry
KW - Europium (III) beta-diketonates
KW - Low-temperature heat capacity
KW - Thermochromism
KW - Thermodynamic functions
KW - TRANSITION
KW - VIBRATION-SPECTRA
KW - HEAT-CAPACITY
KW - DEPENDENCE
UR - http://www.scopus.com/inward/record.url?scp=85070934042&partnerID=8YFLogxK
U2 - 10.1016/j.jct.2019.105904
DO - 10.1016/j.jct.2019.105904
M3 - Article
AN - SCOPUS:85070934042
VL - 140
JO - Journal of Chemical Thermodynamics
JF - Journal of Chemical Thermodynamics
SN - 0021-9614
M1 - 105904
ER -
ID: 21345172