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1.
N,N-dimethyl-3-oxa-glutaramic acid was purified and characterized by 1H-NMR, Fourier transform infrared spectroscopy (FT-IR) and elemental analysis. The thermal decomposition of the title compound
was studied by means of thermogravimetry differential thermogravimetry (TG-DTG) and FT-IR. The kinetic parameters of its second-stage
decomposition reaction were calculated and the decomposition mechanism was discussed. The kinetic model function in a differential
form, apparent activation energy and pre-exponential constant of the reaction are 3/2 [(1−α)1/3−1]−1, 203.75 kJ·mol−1 and 1017.95s−1, respectively. The values of ΔS
≠, ΔH
≠ and ΔG
≠ of the reaction are 94.28 J·mol−1·K−1, 203.75 kJ·mol−1 and 155.75 kJ·mol−1, respectively.
Supported by the National Natural Science Foundation of China (Grant No. 20106009) 相似文献
2.
H. X. Ma B. Yan Y. H. Ren Y. Hu Y. L. Guan F. Q. Zhao J. R. Song R. Z. Hu 《Journal of Thermal Analysis and Calorimetry》2011,103(2):569-575
3,3-Dinitroazetidinium (DNAZ) salt of perchloric acid (DNAZ·HClO4) was prepared, it was characterized by the elemental analysis, IR, NMR, and a X-ray diffractometer. The thermal behavior
and decomposition reaction kinetics of DNAZ·HClO4 were investigated under a non-isothermal condition by DSC and TG/DTG techniques. The results show that the thermal decomposition
process of DNAZ·HClO4 has two mass loss stages. The kinetic model function in differential form, the value of apparent activation energy (E
a) and pre-exponential factor (A) of the exothermic decomposition reaction of DNAZ·HClO4 are f(α) = (1 − α)−1/2, 156.47 kJ mol−1, and 1015.12 s−1, respectively. The critical temperature of thermal explosion is 188.5 °C. The values of ΔS
≠, ΔH
≠, and ΔG
≠of this reaction are 42.26 J mol−1 K−1, 154.44 kJ mol−1, and 135.42 kJ mol−1, respectively. The specific heat capacity of DNAZ·HClO4 was determined with a continuous C
p mode of microcalorimeter. Using the relationship between C
p and T and the thermal decomposition parameters, the time of the thermal decomposition from initiation to thermal explosion (adiabatic
time-to-explosion) was evaluated as 14.2 s. 相似文献
3.
Z. Fengqui H. Rongzu S. Jirong G. Hongxu 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(7):1034-1036
The kinetic parameters of the exothermic decomposition of the title compound in a temperatureprogrammed mode have been studied
by means of DSC. The DSC data obtained are fitted to the integral, differential, and exothermic rate equations by the linear
least-squares, iterative, combined dichotomous, and least-squares methods, respectively. After establishing the most probable
general expression of differential and integral mechanism functions by the logical choice method, the corresponding values
of the apparent activation energy (E
a), preexponential factor (A), and reaction order (n) are obtained by the exothermic rate equation. The results show that the empirical kinetic model function in differential
form and the values of E
a and A of this reaction are (1 − α)−4.08, 149.95 kJ mol−1, and 1014.06 s−1, respectively. With the help of the heating rate and kinetic parameters obtained, the kinetic equation of the exothermic
decomposition of the title compound is proposed. The critical temperature of thermal explosion of the compound is 155.71°C.
The above-mentioned kinetic parameters are quite useful for analyzing and evaluating the stability and thermal explosion rule
of the title compound.
The text was submitted by the authors in English. 相似文献
4.
Thermal behavior of 1,2,3-triazole nitrate 总被引:1,自引:0,他引:1
Liang Xue Feng-Qi Zhao Xiao-Ling Xing Zhi-Ming Zhou Kai Wang Hong-Xu Gao Jian-Hua Yi Si-Yu Xu Rong-Zu Hu 《Journal of Thermal Analysis and Calorimetry》2011,104(3):999-1004
The thermal decomposition behaviors of 1,2,3-triazole nitrate were studied using a Calvet Microcalorimeter at four different
heating rates. Its apparent activation energy and pre-exponential factor of exothermic decomposition reaction are 133.77 kJ mol−1 and 1014.58 s−1, respectively. The critical temperature of thermal explosion is 374.97 K. The entropy of activation (ΔS
≠), the enthalpy of activation (ΔH
≠), and the free energy of activation (ΔG
≠) of the decomposition reaction are 23.88 J mol−1 K−1, 130.62 kJ mol−1, and 121.55 kJ mol−1, respectively. The self-accelerating decomposition temperature (T
SADT) is 368.65 K. The specific heat capacity was determined by a Micro-DSC method and a theoretical calculation method. Specific
heat capacity equation is
C\textp ( \textJ mol - 1 \text K - 1 ) = - 42.6218 + 0.6807T C_{\text{p}} \left( {{\text{J mol}}^{ - 1} {\text{ K}}^{ - 1} } \right) = - 42.6218 + 0.6807T (283.1 K < T < 353.2 K). The adiabatic time-to-explosion is calculated to be a certain value between 98.82 and 100.00 s. The critical
temperature of hot-spot initiation is 637.14 K, and the characteristic drop height of impact sensitivity (H
50) is 9.16 cm. 相似文献
5.
Liang Xue Feng-Qi Zhao Xiao-Ling Xing Zhi-Ming Zhou Kai Wang Hong-Xu Gao Jian-Hua Yi Rong-Zu Hu 《Journal of Thermal Analysis and Calorimetry》2010,102(3):989-992
The thermal decomposition behavior of 3,4,5-triamino-1,2,4-triazole dinitramide was measured using a C-500 type Calvet microcalorimeter
at four different temperatures under atmospheric pressure. The apparent activation energy and pre-exponential factor of the
exothermic decomposition reaction are 165.57 kJ mol−1 and 1018.04 s−1, respectively. The critical temperature of thermal explosion is 431.71 K. The entropy of activation (ΔS
≠), enthalpy of activation (ΔH
≠), and free energy of activation (ΔG
≠) are 97.19 J mol−1 K−1, 161.90 kJ mol−1, and 118.98 kJ mol−1, respectively. The self-accelerating decomposition temperature (T
SADT) is 422.28 K. The specific heat capacity of 3,4,5-triamino-1,2,4-triazole dinitramide was determined with a micro-DSC method
and a theoretical calculation method. Specific heat capacity (J g−1 K−1) equation is C
p = 0.252 + 3.131 × 10−3
T (283.1 K < T < 353.2 K). The molar heat capacity of 3,4,5-triamino-1,2,4-triazole dinitramide is 264.52 J mol−1 K−1 at 298.15 K. The adiabatic time-to-explosion of 3,4,5-triamino-1,2,4-triazole dinitramide is calculated to be a certain value
between 123.36 and 128.56 s. 相似文献
6.
L. I. Giménez J. M. Romero S. Bustillo N. L. Jorge M. E. Gómez Vara E. A. Castro 《Russian Journal of General Chemistry》2008,78(6):1273-1276
Thermal decomposition of 3,3,6,6-tetramethyl-1,2,4,5-tetraoxane was examined in methanol solution (1.69×10−2 M) containing cuprous ions (5.05×10−7 M) in the temperature range from 130 to 166°C using UV spectroscopy as analytical method. The ion-catalyzed reaction follows
first-order kinetics with respect to the peroxide and added cuprous ions. The temperature effect on the rate of thermal decomposition
of the title compound was described by the corresponding Arrhenius equations, and its stability in solution was estimated
on a quantitative level. The activation parameters of the initial step of decomposition of 3,3,6,6-tetramethyl-1,2,4,5-tetraoxane
were determined (ΔH
≠ = 14.7±0.8 kcal mol−1; ΔS
≠ = −38.9±1.4 cal mol−1 K−1; ΔG
≠ = 31.0±0.8 kcal mol−1). Electron-transfer mechanism was proposed for the reaction under study.
The text was submitted by the authors in English. 相似文献
7.
Pei Chen Feng‐Qi Zhao Yang Luo Rong‐Zu Hu Sheng‐Li Gao Yu‐Mei Zheng Min‐Zhi Deng Yin Gao 《中国化学》2004,22(9):1056-1063
The thermal decomposition behavior and kinetic parameters of the exothermic decomposition reactions of the title compound in a temperature‐programmed mode have been investigated by means of DSC, TG‐DTG and lower rate Thermolysis/FTIR. The possible reaction mechanism was proposed. The critical temperature of thermal explosion was calculated. The influence of the title compound on the combustion characteristic of composite modified double base propellant containing RDX has been explored with the strand burner. The results show that the kinetic model function in differential form, apparent activation energy Ea and pre‐exponential factor A of the major exothermic decomposition reaction are 1‐a,207.98 kJ*mol?1 and 1015.64 s?1, respectively. The critical temperature of thermal explosion of the compound is 312.87 C. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as: dα/dT=1016.42 (1–α)e‐2.502×104/T As an auxiliary catalyst, the title compound can help the main catalyst lead salt of 4‐hydroxy‐3,5dinitropyridine oxide to enhance the burning rate and reduce the pressure exponent of RDX‐CMDB propellant. 相似文献
8.
Joanna Wiśniewska 《Transition Metal Chemistry》2007,32(1):107-111
The kinetics of the oxidation of promazine by trisoxalatocobaltate(III) were studied in the presence of a large excess of
the cobalt(III) in tris buffer solution using u.v.–vis spectroscopy ([CoIII] = (0.6 − 2) × 10−3
M, [ptz] = 6 × 10−5
M, pH = 6.6–7.8, I = 0.1 M (NaCl), T = 288−308 K, l = 1 cm). The reaction proceeds via two consecutive reversible steps. In the first step, the reaction leads to formation of cobalt(II) species and a stable cationic
radical. In the second step, cobalt(III) is reduced to cobalt(II) ion and a promazine radical is oxidized to the promazine
5-oxide. Linear dependences of the pseudo-first-order rate constants (k
1 and k
2) on [CoIII] with a non-zero intercept were established for both redox processes. Rates of reactions decreased with increasing concentration
of the H+ ion indicating that the promazine and its radical exist in equilibrium with their deprotonated forms, which are reactive
reducing species. The activation parameters for reactions studied were as follows: ΔH≠ = 44 ± 1 kJ mol−1, ΔS≠ = −100 ± 4 JK−1 mol−1 for the first step and ΔH≠ = 25 ± 1 kJ mol−1, ΔS≠ = −169 ± 4 J K−1 mol−1 for the second step, respectively. Mechanistic consequences of all the results are discussed. 相似文献
9.
Z. Fengqi G. Hongxu L. Yang H. Rongzu C. Pei G. Sheng-li Y. Xu-wu S. Qizhen 《Journal of Thermal Analysis and Calorimetry》2006,85(3):791-794
The constant-volume combustion energies of
the lead salts of 2-hydroxy-3,5-dinitropyridine (2HDNPPb) and 4-hydroxy-3,5-dinitropyridine
(4HDNPPb), ΔU
c
(2HDNPPb(s) and 4HDNPP(s)),
were determined as –4441.92±2.43 and –4515.74±1.92
kJ mol–1 , respectively, at 298.15 K. Their
standard enthalpies of combustion, Δc
m
H θ(2HDNPPb(s) and 4HDNPPb(s), 298.15 K), and standard enthalpies of formation,
Δr
m H θ(2HDNPPb(s) and 4HDNPPb(s),
298.15 K) were as –4425.81±2.43, –4499.63±1.92 kJ
mol–1 and –870.43±2.76, –796.65±2.32
kJ mol–1 , respectively. As two combustion
catalysts, 2HDNPPb and 4HDNPPb can enhance the burning rate and reduce the
pressure exponent of RDX–CMDB propellant. 相似文献
10.
Rearrangements of cyclopentadienyl cyanates,isocyanates and their thio-,seleno-, and telluro-analogs
Dushenko G. A. Mikhailova O. I. Mikhailov I. E. Minyaev R. M. Minkin V. I. 《Russian Chemical Bulletin》2009,58(8):1713-1723
Dynamic NMR spectroscopy revealed that pentaphenylcyclopentadienyl isoselenocyanate undergoes reversible hetero-Cope rearrangement
(ΔG
≠
408 K ∼ 22 kcal mol−1, C6D5CD3) giving isomeric selenocyanate in which 1,5-sigmatropic shifts of the SeCN group along the perimeter of the cyclopentadiene
ring occur (ΔG
≠
298 K = 16.7 kcal mol−1, C6D5CD3). On the contrary, pentaphenylcyclopentadienyl iso(thio)cyanates Ph5C5NCO and Ph5C5NCS are structurally rigid compounds on the NMR time scale. The energy barrier to the 3,3-shift of the isoselenocyanate group
in pentaphenylcyclopentadienyl derivative Ph5C5NCSe (ΔG
298 K
≠ = 17.9 kcal mol−1) caclulated using the B3LYP/6-31G** method is 7.6 kcal mol−1 lower than for the unsubstituted analog H5C5NCSe. 相似文献
11.
Molar heat capacity and thermodynamic properties of 1,2-cyclohexane dicarboxylic anhydride [C8H10O3]
X. -C. Lv X. -H. Gao Z. -C. Tan Y. -S. Li L. -X. Sun 《Journal of Thermal Analysis and Calorimetry》2008,92(2):523-527
The molar heat capacity C
p,m of 1,2-cyclohexane dicarboxylic anhydride was measured in the temperature range from T=80 to 390 K with a small sample automated adiabatic calorimeter. The melting point T
m, the molar enthalpy Δfus
H
m and the entropy Δfus
S
m of fusion for the compound were determined to be 303.80 K, 14.71 kJ mol−1 and 48.43 J K−1 mol−1, respectively. The thermodynamic functions [H
T-H
273.15] and [S
T-S
273.15] were derived in the temperature range from T=80 to 385 K with temperature interval of 5 K. The thermal stability of the compound was investigated by differential scanning
calorimeter (DSC) and thermogravimetry (TG), when the process of the mass-loss was due to the evaporation, instead of its
thermal decomposition. 相似文献
12.
Javed MR Rashid MH Nadeem H Riaz M Perveen R 《Applied biochemistry and biotechnology》2009,157(3):483-497
Monomeric extracellular endoglucanase (25 kDa) of transgenic koji (Aspergillus oryzae cmc-1) produced under submerged growth condition (7.5 U mg−1 protein) was purified to homogeneity level by ammonium sulfate precipitation and various column chromatography on fast protein
liquid chromatography system. Activation energy for carboxymethylcellulose (CMC) hydrolysis was 3.32 kJ mol−1 at optimum temperature (55 °C), and its temperature quotient (Q
10) was 1.0. The enzyme was stable over a pH range of 4.1–5.3 and gave maximum activity at pH 4.4. V
max for CMC hydrolysis was 854 U mg−1 protein and K
m was 20 mg CMC ml−1. The turnover (k
cat) was 356 s−1. The pK
a1 and pK
a2 of ionisable groups of active site controlling V
max were 3.9 and 6.25, respectively. Thermodynamic parameters for CMC hydrolysis were as follows: ΔH* = 0.59 kJ mol−1, ΔG* = 64.57 kJ mol−1 and ΔS* = −195.05 J mol−1 K−1, respectively. Activation energy for irreversible inactivation ‘E
a(d)’ of the endoglucanase was 378 kJ mol−1, whereas enthalpy (ΔH*), Gibbs free energy (ΔG*) and entropy (ΔS*) of activation at 44 °C were 375.36 kJ mol−1, 111.36 kJ mol−1 and 833.06 J mol−1 K−1, respectively. 相似文献
13.
The basic kinetic parameters of thermal polymerization of hexafluoropropylene, namely, general rate constants, degree of polymerization,
and their temperature and pressure dependences in the range of 230–290 °C and 2–12 kbar (200–1200 MPa) were determined. The
activation energy (E
act = 132±4 kJ mol−1) and activation volume (ΔV
0
≠ = −27±1 cm3 mol−1) were calculated. The activation energy of thermal initiation of polymerization was estimated. The reaction scheme based
on the assumption about a biradical mechanism of polymerization initiation was proposed. 相似文献
14.
Y. Xu-Wu Z. Hang-Guo S. Wu-Juan W. Xiao-Yan G. Sheng-Li 《Journal of Thermal Analysis and Calorimetry》2008,92(3):961-965
The copper(II) complex of 6-benzylaminopurine (6-BAP) has been prepared with dihydrated cupric chloride and 6-benzylaminopurine.
Infrared spectrum and thermal stabilities of the solid complex have been discussed. The constant-volume combustion energy,
Δc
U, has been determined as −12566.92±6.44 kJ mol−1 by a precise rotating-bomb calorimeter at 298.15 K. From the results and other auxiliary quantities, the standard molar enthalpy
of combustion, Δc
H
m
θ, and the standard molar of formation of the complex, Δf
H
m
θ, were calculated as −12558.24±6.44 and −842.50±6.47 kJ mol−1, respectively. 相似文献
15.
Tandra?Das Biplab?K.?Bera Subhasis?Mallick Parnajyoti?Karmakar Arup?Mandal Subala?Mondal Gauri?S.?De Alak?K.?Ghosh 《Transition Metal Chemistry》2010,35(7):885-890
The interaction of thiosemicarbazide with the title complex has been studied spectrophotometrically in aqueous medium as a
function of [complex], [thiosemicarbazide], pH and temperature at constant ionic strength. At pH 7.4, the reaction shows two
distinct paths; both of which are [thiosemicarbazide] dependent. A parallel reaction scheme fits well with the experimental
findings. An associative interchange mechanism is proposed for both the paths; the activation parameters calculated from Eyring
plots are ΔH1≠ = 14.2 ± 0.8 kJ mol−1, ΔS1≠ = −241 ± 2 JK−1 mol−1, ΔH2≠ = 30.8 ± 1.4 kJ mol−1 and ΔS2≠ = −236 ± 4 JK−1 mol−1. From the temperature dependence of the outer sphere association complex equilibrium constants, the thermodynamic parameters
calculated are ΔH1° = 34.25 ± 1.9 kJ mol−1, ΔS1° = 146 ± 6 J K−1 mol−1 and ΔH2° = 9.4 ± 1.1 kJ mol−1, ΔS2° = 71 ± 3 JK−1 mol−1, which gives a negative ΔG° at all temperatures studied, supporting the spontaneous formation of an outer sphere association
complex. 相似文献
16.
The relative enthalpies, ΔHo (0) and ΔHo (298.15), of stationary points (four minimum and three transition structures) on the •O3H potential energy surface were calculated with the aid of the G3MP2B3 as well as the CCSD(T)–CBS (W1U) procedures from which
we earlier found mean absolute deviations (MAD) of 3.9 kJ mol−1 and 2.3 kJ mol−1, respectively, between experimental and calculated standard enthalpies of the formation of a set of 32 free radicals. For
CCSD(T)-CBS (W1U) the well depth from O3 + H• to trans-•O3H, ΔHowell(298.15) = −339.1 kJ mol−1, as well as the reaction enthalpy of the overall reaction O3 + H•→O2 + •OH, ΔrHo(298.15) = −333.7 kJ mol−1, and the barrier of bond dissociation of trans-•O3H → O2 + •OH, ΔHo(298.15) = 22.3 kJ mol−1, affirm the stable short-lived intermediate •O3H. In addition, for radicals cis-•O3H and trans-•O3H, the thermodynamic functions heat capacity Cop(T), entropy So (T), and thermal energy content Ho(T) − Ho(0) are tabulated in the range of 100 − 3000 K. The much debated calculated standard enthalpy of the formation of the trans-•O3H resulted to be ΔfHo(298.15) = 31.1 kJ mol −1 and 32.9 kJ mol −1, at the G3MP2B3 and CCSD(T)-CBS (W1U) levels of theory, respectively. In addition, MR-ACPF-CBS calculations were applied
to consider possible multiconfiguration effects and yield ΔfHo(298.15) = 21.2 kJ mol −1. The discrepancy between calculated values and the experimental value of −4.2 ± 21 kJ mol−1 is still unresolved.
Note added in proof: Yu-Ran Luo and J. Alistair Kerr, based on the discussion in reference 12, recently presented an experimental
value of ΔfHo(298.15) = 29.7 ± 8.4 kJ mol−1 in the 85th edition of the CRC Handbook of Chemistry and Physics (in progress). 相似文献
17.
J. N. Zhang Z. C. Tan Q. F. Meng Q. Shi B. Tong S. X. Wang 《Journal of Thermal Analysis and Calorimetry》2009,95(2):461-467
The heat capacities (C
p,m) of 2-amino-5-methylpyridine (AMP) were measured by a precision automated adiabatic calorimeter over the temperature range
from 80 to 398 K. A solid-liquid phase transition was found in the range from 336 to 351 K with the peak heat capacity at
350.426 K. The melting temperature (T
m), the molar enthalpy (Δfus
H
m0), and the molar entropy (Δfus
S
m0) of fusion were determined to be 350.431±0.018 K, 18.108 kJ mol−1 and 51.676 J K−1 mol−1, respectively. The mole fraction purity of the sample used was determined to be 0.99734 through the Van’t Hoff equation.
The thermodynamic functions (H
T-H
298.15 and S
T-S
298.15) were calculated. The molar energy of combustion and the standard molar enthalpy of combustion were determined, ΔU
c(C6H8N2,cr)= −3500.15±1.51 kJ mol−1 and Δc
H
m0 (C6H8N2,cr)= −3502.64±1.51 kJ mol−1, by means of a precision oxygen-bomb combustion calorimeter at T=298.15 K. The standard molar enthalpy of formation of the crystalline compound was derived, Δr
H
m0 (C6H8N2,cr)= −1.74±0.57 kJ mol−1. 相似文献
18.
Wang S. X. Tan Z. C. Di Y. Y. Xu F. Wang M. H. Sun L. X. Zhang T. 《Journal of Thermal Analysis and Calorimetry》2004,76(1):335-342
As one primary component of Vitamin B3, nicotinic acid [pyridine 3-carboxylic acid] was synthesized, and calorimetric study and thermal analysis for this compound
were performed. The low-temperature heat capacity of nicotinic acid was measured with a precise automated adiabatic calorimeter
over the temperature rang from 79 to 368 K. No thermal anomaly or phase transition was observed in this temperature range.
A solid-to-solid transition at T
trs=451.4 K, a solid-to-liquid transition at T
fus=509.1 K and a thermal decomposition at T
d=538.8 K were found through the DSC and TG-DTG techniques. The molar enthalpies of these transitions were determined to be
Δtrs
H
m=0.81 kJ mol-1, Δfus
H
m=27.57 kJ mol-1 and Δd
H
m=62.38 kJ mol-1, respectively, by the integrals of the peak areas of the DSC curves.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
19.
Joanna Wiśniewska 《Transition Metal Chemistry》2007,32(6):811-815
The kinetics of the electron-transfer reactions between promazine (ptz) and [Co(en)2(H2O)2]3+ in CF3SO3H solution ([CoIII] = (2–6) × 10−3
m, [ptz] = 2.5 × 10−4
m, [H+] = 0.02 − 0.05 m, I = 0.1 m (H+, K+, CF3SO
3
−
), T = 288–308 K) and [Co(edta)]− in aqueous HCl ([CoIII] = (1 − 4) × 10−3
m, [ptz] = 1 × 10−4
m, [H+] = 0.1 − 0.5 m, I = 1.0 m (H+, Na+, Cl−), T = 313 − 333 K) were studied under the condition of excess CoIII using u.v.–vis. spectroscopy. The reactions produce a CoII species and a stable cationic radical. A linear dependence of the pseudo-first-order rate constant (k
obs) on [CoIII] with a non-zero intercept was established for both redox processes. The rate of reaction with the [Co(en)2(H2O)2]3+ ion was found to be independent of [H+]. In the case of the [Co(edta)]− ion, the k
obs dependence on [H+] was linear and the increasing [H+] accelerates the rate of the outer-sphere electron-transfer reaction. The activation parameters were calculated as follows:
ΔH
≠ = 105 ± 4 kJ mol−1, ΔS
≠ = 93 ± 11 J K−1mol−1 for [Co(en)2(H2O)2]3+; ΔH
≠ = 67 ± 9 kJ mol−1, ΔS
≠ = − 54 ± 28 J K−1mol−1 for [Co(edta)]−. 相似文献
20.
W. Xinmin Q. Chuansong Q. Songsheng T. Zhicheng 《Journal of Thermal Analysis and Calorimetry》2007,90(2):569-573
Rare-earth perchlorate complex coordinated with glycine [Nd2(Gly)6(H2O)4](ClO4)6·5H2O was synthesized and its structure was characterized by using thermogravimetric analysis (TG), differential thermal analysis
(DTA), chemical analysis and elementary analysis. Its purity was 99.90%. Heat capacity measurement was carried out with a
high-precision fully-automatic adiabatic calorimeter over the temperature range from 78 to 369 K. A solid-solid phase transformation
peak was observed at 256.97 K, with the enthalpy and entropy of the phase transformation process are 4.438 kJ mol−1 and 17.270 J K−1 mol−1, respectively. There is a big dehydrated peak appears at 330 K, its decomposition temperature, decomposition enthalpy and
entropy are 320.606 K, 41.364 kJ mol−1 and 129.018 J K−1 mol−1, respectively. The polynomial equations of heat capacity of this compound in different temperature ranges have been fitted.
The standard enthalpy of formation was determined to be −8023.002 kJ mol−1 with isoperibol reaction calorimeter at 298.15 K. 相似文献