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1.
I. A. Letyanina N. N. Smirnova A. V. Markin V. A. Ruchenin V. N. Larina V. V. Sharutin O. V. Molokova 《Journal of Thermal Analysis and Calorimetry》2011,103(1):355-363
In the present research for the first time, the heat capacity
C\textp ° C_{\text{p}}^{ \circ } of crystalline tetraphenylantimony acetophenoneoxymate Ph4SbONCPhMe has been measured using the methods of precision adiabatic vacuum calorimetry over the range from 6 to 350 K, the
standard thermodynamic functions: heat capacity
C\textp ° (T ) C_{\text{p}}^{ \circ } (T ) , enthalpy H°(T) − H°(0), entropy S°(T), and Gibbs function G°(T) − H°(0) have been calculated over the range from T → 0 K to 350 K. Low-temperature (20 K ≤ T ≤ 50 K) heat capacity data have shown a chain-layered structure topology of the compound under study. The energy of combustion
of the compound has been determined in the isothermal combustion calorimeter with a stationary bomb. The standard thermodynamic
functions of formation of crystalline Ph4SbONCPhMe at 298.15 K have been calculated. The differential scanning calorimetry and thermogravimetric analysis studies have
shown the compound melts with decomposition and its melting temperature has been estimated. Thermodynamic properties of Ph4SbONCPhMe, Ph5Sb and Ph4SbONCPh2 have been compared. 相似文献
2.
A. V. Markin V. A. Ruchenin N. N. Smirnova E. A. Gorina S. N. Titova L. V. Kalakutskaya G. A. Domrachev 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(12):2032-2038
The temperature dependence of heat capacity C
p
o = f(T) of fullerene derivative (t-Bu)12C60 has been measured by a adiabatic vacuum calorimeter over the temperature range T = 6–350 K and by a differential scanning calorimeter over the temperature range T = 330–420 K for the first time. The low-temperature (T ≤ 50 K) dependence of the heat capacity was analyzed based on Debye’s the heat capacity theory of solids and its fractal
variant. As a consequence, the conclusion about structure heterodynamicity is given. The experimental results have been used
to calculate the standard thermodynamic functions C
p
o (T), H
o(T)−H
o(0), S
o(T) and G
o(T) − H
o(0) over the range from T → 0 to 420 K. The standard entropy of formation at 298.15 K of fullerene derivative under study was calculated. The temperature
of decomposition onset of derivative was determined by differential scanning calorimetery and thermogravimetric analysis.
The standard thermodynamic characteristics of (t-Bu)12C60 and C60 fullerite were compared. 相似文献
3.
A. V. Markin N. N. Smirnova D. V. Lyakaev M. N. Klimova V. V. Sharutin O. K. Sharutina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(10):1913-1920
The temperature dependence of the heat capacity of triphenylantimony dibenzoate Ph3Sb(OC(O)Ph)2 is studied in the range of 6–480 K by means of precision adiabatic vacuum calorimetry and differential scanning calorimetry. The melting of the compound is observed in this temperature range, and its standard thermodynamic characteristics are identified and analyzed. Ph3Sb(OC(O)Ph)2 is obtained in a metastable amorphous state in a calorimeter. The standard thermodynamic functions of Ph3Sb(OC(O)Ph)2 in the crystalline and liquid states are calculated from the obtained experimental data: Cp°(T), H°(T)–H°(0), S°(T), and G°(T)–H°(0) for the region from T → 0 to 480 K. The standard entropy of formation of the compound in the crystalline state at T = 298.15 K is determined. Multifractal processing of the low-temperature (T < 50 K) heat capacity of the compound is performed. It is concluded that the structure of the compound has a planar chain topology. 相似文献
4.
I. A. Letyanina A. V. Markin N. N. Smirnova A. V. Gushchin D. V. Shashkin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(8):1189-1195
The heat capacity of triphenylantimony diacrylate Ph3Sb(O2CCH=CH2)2 was studied in an adiabatic vacuum calorimeter at 6?C350 K and differential scanning calorimeter at 330?C450 K. Melting was revealed at these temperatures; the melting point was estimated at 428.4 ± 0.5 K. It was accompanied by the partial decomposition of the substance. The low-temperature (20 K ?? T ?? 50 K) heat capacity was treated using the Debye theory of the heat capacity of solids and its multifractal model. The type of the structure topology was determined. The standard thermodynamic functions C p o (T), H o(T) ? H o(0), S o(T), and G o(T) ? H o(0) of the compound in the crystal state were calculated from the obtained experimental data in the range from T ?? 0 to 428 K. The standard entropy of the formation of the crystalline compound Ph3Sb(O2CCH=CH2)2 at T = 298.15 K was determined. 相似文献
5.
N. N. Smirnova T. A. Bykova N. A. Polotnyanko N. D. Shikina I. L. Khodakovskii 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(11):1851-1855
The temperature dependence of the heat capacity C
p
o = f(T) of palladium oxide PdO(cr.) was studied for the first time in an adiabatic vacuum calorimeter in the range of 6.48–328.86
K. Standard thermodynamic functions C
p
o(T), H
o(T) — H
o(0), S
o(T), and G
o(T) — H
o(0) in the range of T → 0 to 330 K (key quantities in different thermodynamic calculations with the participation of palladium compounds) were
calculated on the basis of the experimental data. Based on an analysis of studies on determining the thermodynamic properties
of PdO(cr.), the following values of absolute entropy, standard enthalpy, and Gibbs function of the formation of palladium
oxide are recommended: S
o(298.15) = 39.58 ± 0.15 J/(K mol), Δf
H
o(298.15) = −112.69 ± 0.32 kJ/mol, Δf
G
o(298.15) = −82.68 ± 0.35 kJ/mol. The stability of Pd(OH)2 (amorph.) with respect to PdO(cr.) was estimated. 相似文献
6.
I. E. Paukov Yulia A. Kovalevskaya Elena V. Boldyreva 《Journal of Thermal Analysis and Calorimetry》2008,93(2):423-428
Heat capacity C
p(T) of the orthorhombic polymorph of L-cysteine was measured in the temperature range 6–300 K by adiabatic calorimetry; thermodynamic functions were calculated
based on these measurements. At 298.15 K the values of heat capacity, C
p; entropy, S
m0(T)-S
m0(0); difference in the enthalpy, H
m0(T)-H
m0(0), are equal, respectively, to 144.6±0.3 J K−1 mol−1, 169.0±0.4 J K−1 mol−1 and 24960±50 J mol−1. An anomaly of heat capacity near 70 K was registered as a small, 3–5% height, diffuse ‘jump’ accompanied by the substantial
increase in the thermal relaxation time. The shape of the anomaly is sensitive to thermal pre-history of the sample. 相似文献
7.
Thermodynamic stability of CdMoO4 was determined
by measuring the vapor pressures of Cd and MoO3 bearing
gaseous species. Th vaporization reaction could be described as CdMoO4(s)+MoO2(s)
=Cd(g)+2/n(MoO3)n
(n=3, 4 and 5). The vapor pressures of
the cadmium (p
Cd)
and trimer (p
(MoO3)3)
measured in the temperature range 987≤T/K≤1111
could be expressed, respectively, as ln (p
Cd/Pa)
= –32643.9/T+29.46±0.08 and
ln(p
(MoO3)3/Pa) = –32289.6/T+29.28±0.08. The standard molar Gibbs free
energy of formation of CdMoO4(s),
derived from the vaporization results could be expressed by the equations:
°f
G
CdMoO4
(s)
0= –1002.0+0.267T±14.5 kJ mol–1
(987≤T/K≤1033) and °f
G
CdMoO4 (s)
0
= –1101.9+0.363T±14.4 kJ mol–1
(1044≤T/K≤1111). The standard enthalpy
of formation of CdMoO4(s)
was found to be –1015.4±14.5 kJ mol–1
. 相似文献
8.
The heat capacity of crystalline α-platinum dichloride was measured for the first time in the temperature intervals from 11
to 300 K (vacuum adiabatic microcalorimeter) and from 300 to 620 K (differential scanning calorimetry). In the 300–620 K temperature
interval, the C°
p
values for α-PtCl2 (cr) coincide with the heat capacity of CrCl2 (cr) within the limits of experimental error, which made it possible to estimate the heat capacity of α-PtCl2 (cr) at higher temperatures. The approximating equation of the temperature dependence of the heat capacity in the interval
from 298 to 900 K C°
p
(±0.8) = 63.5 + 21.4·10−3
T + 0.883·105/T
2 (J mol−1 K−1) was derived using the experimental values, as well as the literature data on the heat capacity of CrCl2 (cr). For the standard conditions, the C°
p,298.15 and S°298.15 values are 70.92±0.08 and 100.9±0.33 J mol−1 K, respectively; H°298.15 − H°0 = 14 120±42 J mol−1.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1136–1138, June, 2008. 相似文献
9.
M.-H. Wang Z.-C. Tan Q. Shi L.-X. Sun T. Zhang 《Journal of Thermal Analysis and Calorimetry》2006,84(2):413-418
The
heat capacities of 2-benzoylpyridine were measured with an automated adiabatic
calorimeter over the temperature range from 80 to 340 K. The melting point,
molar enthalpy, ΔfusHm,
and entropy, ΔfusSm,
of fusion of this compound were determined to be 316.49±0.04 K, 20.91±0.03
kJ mol–1 and 66.07±0.05 J mol–1
K–1, respectively. The purity of the compound
was calculated to be 99.60 mol% by using the fractional melting technique.
The thermodynamic functions (HT–H298.15) and (ST–S298.15) were calculated based
on the heat capacity measurements in the temperature range of 80–340
K with an interval of 5 K. The thermal properties of the compound were further
investigated by differential scanning calorimetry (DSC). From the DSC curve,
the temperature corresponding to the maximum evaporation rate, the molar enthalpy
and entropy of evaporation were determined to be 556.3±0.1 K, 51.3±0.2
kJ mol–1 and 92.2±0.4 J K–1
mol–1, respectively, under the experimental
conditions. 相似文献
10.
A. V. Markin I. A. Letyanina N. N. Smirnova V. V. Sharutin O. V. Molokova 《Journal of Thermal Analysis and Calorimetry》2013,111(2):1499-1502
For the first time, the energy of combustion Δc U of crystalline triphenylantimony bis(acetophenoneoximate) Ph3Sb(ONCPhMe)2 has been measured at T = 298.15 K using the isothermal combustion calorimeter with a stationary bomb. The standard molar enthalpy of combustion Δc Hº, the standard molar enthalpy Δf Hº, and free Gibbs energy Δf Gº of formation of the above oximate have been calculated. 相似文献
11.
N. N. Smirnova B. V. Lebedev T. A. Bykova A. V. Markin D. R. Tur 《Journal of Thermal Analysis and Calorimetry》2009,95(1):229-234
By adiabatic vacuum and dynamic calorimetry, heat capacity for poly[bis(trifluoroethoxy)phosphazene] has been determined over the 6–620 K range. Physical transformations of the polymer on its heating
and cooling have been detected and characterized. Smoothed heat capacity C
p0(T) and standard thermodynamic functions (H
0(T)-H
0(0), S
0(T) and G
0(T)-H
0(0)) of poly[bis(trifluoroethoxy)phosphazene] have been evaluated for the temperature range from T→0 to 560 K. The standard entropy of formation Δf
S
0 at T=298.15 K has been also determined. Fractal dimensions D in the heat capacity function of the multifractal variant of Debye’s theory of heat capacity of solids characterizing the
heterodynamics of the tested polymer have been determined. 相似文献
12.
Y. Y. Di Z. C. Tan L. W. Li S. L. Gao L. X. Sun 《Journal of Thermal Analysis and Calorimetry》2007,87(2):545-551
Low-temperature heat capacities of a solid
complex Zn(Val)SO4·H2O(s) were measured by a precision automated adiabatic
calorimeter over the temperature range between 78 and 373 K. The initial dehydration
temperature of the coordination compound was determined to be, T
D=327.05
K, by analysis of the heat-capacity curve. The experimental values of molar
heat capacities were fitted to a polynomial equation of heat capacities (C
p,m) with the reduced temperatures
(x), [x=f (T)], by least
square method. The polynomial fitted values of the molar heat capacities and
fundamental thermodynamic functions of the complex relative to the standard
reference temperature 298.15 K were given with the interval of 5 K.
Enthalpies of dissolution of the [ZnSO4·7H2O(s)+Val(s)] (Δsol
H
m,l
0)
and the Zn(Val)SO4·H2O(s) (Δsol
H
m,2
0) in 100.00 mL of 2 mol dm–3 HCl(aq) at T=298.15
K were determined to be, Δsol
H
m,l
0=(94.588±0.025) kJ mol–1 and Δsol
H
m,2
0=–(46.118±0.055)
kJ mol–1, by means of a homemade isoperibol
solution–reaction calorimeter. The standard molar enthalpy of formation
of the compound was determined as: Δf
H
m
0
(Zn(Val)SO4·H2O(s), 298.15 K)=–(1850.97±1.92) kJ mol–1,
from the enthalpies of dissolution and other auxiliary thermodynamic data
through a Hess thermochemical cycle. Furthermore, the reliability of the Hess
thermochemical cycle was verified by comparing UV/Vis spectra and the refractive
indexes of solution A (from dissolution of the [ZnSO4·7H2O(s)+Val(s)] mixture
in 2 mol dm–3 hydrochloric acid) and solution
A’ (from dissolution of the complex Zn(Val)SO4·H2O(s) in 2 mol dm–3
hydrochloric acid). 相似文献
13.
N. N. Smirnova A. V. Markin Ya. S. Samosudova G. M. Ignat’eva A. M. Muzafarov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(5):784-791
The temperature dependence of the heat capacity of carbosilane dendrimer of the seventh generation of series 3 × 3 with phenylic
substituent on the initial branching center and terminal butyl groups was studied by the methods of precision adiabatic vacuum
calorimetry and differential scanning calorimetry over the temperature range T = 7–580 K for the first time. Physical transformations in the above temperature range were detected and their standard thermodynamic
characteristics estimated and analyzed. The experimental results were used to calculate standard thermodynamic functions C
p
∘(T), H
∘(T)-H
∘(0), S
∘(T)-S
∘(0), and G
∘(T)-H
∘(0) (0) over the range T → 0–580 K and standard entropy of formation of dendrimer at T = 298.15 K. The thermodynamic properties of carbosilane dendrimers of the seventh generation of series 4 × 3 with terminal
butyl groups and the samples studied in this work were compared. 相似文献
14.
N. N. Smirnova K. V. Kandeev T. A. Bykova T. G. Kulagina A. M. Fainleib 《Russian Chemical Bulletin》2006,55(5):845-851
The temperature dependences of the heat capacity of partially crystalline linear polyurethanes based on 1,6-hexamethylenediisocyanate
with butane-1,4-diol and hexane-1,6-diol were studied for the first time in a temperature range of 6–460 K by the methods
of adiabatic vacuum and dynamic calorimetry. Physical changes in the state of polyurethanes were revealed and characterized;
the standard thermodynamic functions, namely, C
p
°(T), H°(T)-H°(0), S°(T), and G°(T)-H°(0), were calculated from the obtained experimental data in the temperature range from T → 0 to 460 K for the polymers in the crystalline, glassy, highly elastic, and liquid states. The energies of combustion of
the polymers were measured by the bomb calorimetry method, and the standard thermodynamic characteristics of their formation
at 298.15 K were calculated. The thermodynamic characteristics of bulk polycondensation of 1,6-hexamethylenediisocyanate with
butane-1,4-diol and hexane-1,6-diol to form linear aliphatic polyurethanes-{4,6} and-{6,6} were determined in the range from
T → 0 to 350 K at p° = 0.1 MPa. The thermodynamic properties of the polyurethanes under study and polymers of isomeric structure were compared.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 817–823, May, 2006. 相似文献
15.
F. Xu L.-X. Sun Z.-C. Tan J.-G. Liang Y.-Y. Di Q.-F. Tian T. Zhang 《Journal of Thermal Analysis and Calorimetry》2004,76(2):481-489
Molar heat capacities (C
p,m) of aspirin were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range
from 78 to 383 K. No phase transition was observed in this temperature region. The polynomial function of C
p,m
vs. T was established in the light of the low-temperature heat capacity measurements and least square fitting method. The corresponding
function is as follows: for 78 K≤T≤383 K, C
p,m/J mol-1 K-1=19.086X
4+15.951X
3-5.2548X
2+90.192X+176.65, [X=(T-230.50/152.5)]. The thermodynamic functions on the base of the reference temperature of 298.15 K, {ΔH
T -ΔH
298.15} and {S
T-S
298.15}, were derived. Combustion energy of aspirin (Δc
U
m) was determined by static bomb combustion calorimeter. Enthalpy of combustion (Δc
H
o
m) and enthalpy of formation (Δf
H
o
m) were derived through Δc
U
m as - (3945.26±2.63) kJ mol-1 and - (736.41±1.30) kJ mol-1, respectively.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
16.
B. Tong Z. C. Tan J. N. Zhang S. X. Wang 《Journal of Thermal Analysis and Calorimetry》2009,95(2):469-475
The low-temperature heat capacity C
p,m of erythritol (C4H10O4, CAS 149-32-6) was precisely measured in the temperature range from 80 to 410 K by means of a small sample automated adiabatic
calorimeter. A solid-liquid phase transition was found at T=390.254 K from the experimental C
p-T curve. The molar enthalpy and entropy of this transition were determined to be 37.92±0.19 kJ mol−1 and 97.17±0.49 J K−1 mol−1, respectively. The thermodynamic functions [H
T-H
298.15] and [S
T-S
298.15], were derived from the heat capacity data in the temperature range of 80 to 410 K with an interval of 5 K. The standard
molar enthalpy of combustion and the standard molar enthalpy of formation of the compound have been determined: Δc
H
m0(C4H10O4, cr)= −2102.90±1.56 kJ mol−1 and Δf
H
m0(C4H10O4, cr)= − 900.29±0.84 kJ mol−1, by means of a precision oxygen-bomb combustion calorimeter at T=298.15 K. DSC and TG measurements were performed to study the thermostability of the compound. The results were in agreement
with those obtained from heat capacity measurements. 相似文献
17.
N. N. Smirnova Yu. A. Zakharova V. A. Ruchenin O. G. Zamyshlyayeva 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(4):539-547
The temperature dependence of the heat capacity of cross-linked and branched (co)polymers based on tris- and bis-(pentafluorophenyl)germanes is studied in the temperature range of 6–7 to 535–570 K, using adiabatic vacuum and differential
scanning calorimeters. In the indicated temperature range, physical transformations are revealed and their thermodynamic characteristics
are determined. The obtained experimental data are used to calculate the thermodynamic functions of (co)polymers: C
p
/°, H°(T) - H°(0), S°(T) - S°(0), and G°(T) - H°(0) in the range of T → 0 to 535 K for the branched (co)polymer and from T → 0 to 500 K for the cross-linked polymer. Their standard entropies of formation are determined at 298.15 K. The obtained
results are compared with analogous data for hyperbranched perfluorinated polyphenylenegermane studied earlier. The effect
of the structure of polyphenylenegermanes on their thermodynamic properties is analyzed. 相似文献
18.
N. N. Smirnova O. V. Stepanova T. A. Bykova A. V. Markin E. A. Tatarinova A. M. Muzafarov 《Russian Chemical Bulletin》2007,56(10):1991-1995
Temperature dependences of the heat capacity of carbosilane dendrimers with butyl terminal groups of the seventh and ninth
generations were determined in the temperature range from 6 to 600 K by precision adiabatic vacuum calorimetry and differential
scanning (dynamic) calorimetry. The physical transitions were revealed and their thermodynamic characteristics were analyzed.
The experimental data obtained were used to calculate the standard thermodynamic functions C
p
(T), H°(T) − H°(0), S°(T), and G°(T) − H°(0) for the temperature range from T → 0 to 600 K. The thermodynamic function-molar weight isotherms for the dendrimers of the third–ninth generations with terminal
butyl groups in the glassy and highly elastic state are linear.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1924–1928, October, 2007. 相似文献
19.
A. V. Markin N. N. Smirnova I. E. Boronina V. A. Ruchenin A. G. Lyapin 《Russian Chemical Bulletin》2008,57(9):1975-1980
Temperature dependences of the heat capacities of disordered graphite-like nanostructures prepared by the thermobaric treatment
of fullerite C60 (p = 2 and 8 GPa, T = 1373 K) were measured in the temperature ranges from 7 to 360 K in an adiabatic vacuum calorimeter and from 330 to 650
K in a differential scanning calorimeter. At T < 50 K, the dependences obtained were analyzed using the Debye theory of the heat capacity of solids and its multifractal
version. The fractal dimensions D were determined and some conclusions on the heterodynamic character of the structures studied were made. The thermodynamic
functions C
p
o
T), H
o(T) − H
o(0), S
o(T) − S
o(0), and G
o(T) − H
o(0) were calculated in the temperature range from T → 0 to 610 (650) K. The thermodynamic properties of the graphite-like nanostructures studied and some carbon allotropes were
compared. The standard entropies of formation Δf
S
o of the graphite nanostructures studied and diamond were calculated along with the standard entropies of the reactions of
their synthesis from the face-centered cubic phase of fullerite C60 and their interconversions at T = 298.15 K.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1940–1945, September, 2008. 相似文献
20.
A. V. Arapova M. P. Bubnov G. A. Abakumov V. K. Cherkasov N. A. Skorodumova N. N. Smirnova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(8):1257-1261
The heat capacity of paramagnetic (2,2′-dipyridyl)bis(4-chloro-3,6-di-tert-butyl-o-benzosemi-quinone)cobalt was studied over the temperature range 8–390 K by precision adiabatic vacuum and high-accuracy dynamic
calorimetry. The physical transformation observed at 309–388 K was caused by the transition of the semiquinone-catecholate
to bis-semiquinone form of the complex. Above 388 K, thermal destruction was superimposed on the physical transition. The
experimental data were used to calculate the standard thermodynamic functions C
p
o (T), H
o(T)−H
o(0), S
o(T), and G
o(T)−H
o(0) at temperatures from T → 0 to 300 K. An analysis of the low-temperature heat capacity of the complex in terms of the Debye theory of the heat capacity
of solids and its multifractal generalization led us to conclude that the complex had a predominantly chain structure. 相似文献