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1.
The enthalpies of combustion (ΔH
comb) of five primary, secondary, and tertiary alkyl(aryl)arsines in the condensed state were calculated using the equation ΔH
comb = −385.8–110.3N, where N is the number of bond-forming electrons. The dependence presented is used for the calculation of the enthalpies of combustion
of full esters and amidoesters of arsinous acid of noncyclic and cyclic structures.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1042–1043, May, 2007. 相似文献
2.
M. A. V. Ribeiro da Silva C. P. F. Santos M. J. S. Monte C. A. D. Sousa 《Journal of Thermal Analysis and Calorimetry》2006,83(3):533-539
The
standard (p0=0.1
MPa) molar enthalpies of formation, ΔfHm0, for
crystalline phthalimides: phthalimide, N-ethylphthalimide
and N-propylphthalimide were derived from
the standard molar enthalpies of combustion, in oxygen, at the temperature
298.15 K, measured by static bomb-combustion calorimetry, as, respectively,
– (318.0±1.7), – (350.1±2.7) and – (377.3±2.2)
kJ mol–1. The standard molar enthalpies of
sublimation, ΔcrgHm0, at T=298.15
K were derived by the Clausius-Clapeyron equation, from the temperature dependence
of the vapour pressures for phthalimide, as (106.9±1.2) kJ mol–1
and from high temperature Calvet microcalorimetry for phthalimide, N-ethylphthalimide and N-propylphthalimide
as, respectively, (106.3±1.3), (91.0±1.2) and (98.2±1.4)
kJ mol–1.
The derived standard molar enthalpies of formation,
in the gaseous state, are analysed in terms of enthalpic increments and interpreted
in terms of molecular structure. 相似文献
3.
Maria D. M. C. Ribeiro da Silva N. R. M. Araújo A. L. R. Silva L. C. M. da Silva N. P. S. M. Barros J. M. Gonçalves M. A. V. Ribeiro da Silva 《Journal of Thermal Analysis and Calorimetry》2007,87(1):291-296
The standard (p
0=0.1
MPa) molar enthalpies of formation, at T=298.15
K, in the gaseous phase, for three tetradentate Schiff bases involving a N2O2
set, N,N’-bis(salicylaldehydo)cyclohexanediimine
(H2salch), N,N’-bis(acetylacetone)cyclohexanediimine (H2acacch)
and N,N’-bis(benzoylacetone)cyclohexanediimine
(H2bzacch), were determined from their enthalpies of
combustion and sublimation, obtained by static bomb calorimetry in oxygen
and by the Knudsen effusion technique, respectively. The results are compared
with identical parameters for related compounds previously studied, resulting
from the condensation of salicylaldehyde or β-diketone with aliphatic
diamines. 相似文献
4.
The solution enthalpies of formamide and N,N-dimethyl- and diethylamides of formic and acetic acids in a water—glycerol mixed solvent were measured and the solvation
enthalpies were calculated. The enthalpy coefficients of amide—glycerol pair interactions in aqueous solution were calculated.
The effect of the mixture composition and the structure and properties of solutes on the enthalpic characteristics were considered.
The contributions of structural fragments of the amide molecules to the enthalpic characteristics of solutions were calculated
in the framework of the proposed additive scheme. This made it possible to analyze the role of nonspecific and specific solvations
of the amides in solution and predict the vaporization, solution, and solvation enthalpies and enthalpy coefficients of pair
interactions of experimentally unstudied N-methylformamide, N-ethylformamide, N-methyl-N-ethylformamide, N-methylacetamide, N-ethylacetamide, and N-methyl-N-ethylacetamide in a water—glycerol mixture, as well as donor numbers for these amides.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1363–1370, June, 2005. 相似文献
5.
V. V. Ovchinnikov L. I. Lapteva E. Yu. Sitnikova A. I. Konovalov 《Russian Chemical Bulletin》2000,49(9):1522-1525
The enthalpies of solvation of four geometric isomers of 2,5-dimethyl-1-phenyl-1-thioxophosphorinan-4-one in chloroform, nitrobenzene,
and methanol were calculated using the enthalpies of vaporization of the isomers determined by the modified Solomonov—Konovalov
method from the enthalpies of solution of the compounds in CCl4 andp-xylene and molar refractions. The enthalpies of formation (ΔH
f
o) of the isomers in the condensed and gas phase were assessed in the framework of Benson's group additivity scheme by summing
the ΔH
f
o values for phosphacycloketone fragments obtained from molecular mechanics calculations with the contributions of the phenyl
group and S atom attached to the P atom.
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1533–1536, September, 2000. 相似文献
6.
L. A. Kochergina A. V. Volkov E. A. Khokhlova O. N. Krutova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(5):881-889
The heat effects of the reaction of aqueous solution of L-serine with aqueous solutions of HNO3 and KOH were determined by calorimetry at temperatures of 288.15, 298.15, and 308.15 K, and ionic strength values of 0.2,
0.5, and 1.0 (background electrolyte, KNO3). Standard thermodynamic characteristics (Δr
H
o, Δr
G
o, Δr
S
o, ΔC
p
o) of the acid-base reactions in aqueous solutions of L-serine were calculated. The effect of the concentration of background
electrolyte and temperature on the heats of dissociation of amino acid was considered. The combustion energy of L-serine by
bomb calorimetry in the medium of oxygen was determined. The standard combustion and formation enthalpies of crystalline L-serine
were calculated. The heats of dissolution of crystalline L-serine in water and solutions of potassium hydroxide at 298.15
K were measured by direct calorimetry. The standard enthalpies of formation of L-serine and products of its dissociation in
aqueous solution were calculated. 相似文献
7.
P. O. Dunstan 《Journal of Thermal Analysis and Calorimetry》2009,97(2):755-760
The [InCl3(L)
n
] (where L is 2,2′-bipyridine (bipy), 2,2′-bipyridine N,N′-dioxide (bipyNO), N,N-dimethylacetamide (dma), urea (u), thiourea (tu) or 1,1,3,3-tetramethylthiourea (tmtu); n = 1.5, 3 or 4) were synthesized and characterized by melting points, elemental analysis, thermal analysis and IR spectroscopy.
The enthalpies of dissolution of the adducts, Indium(III) chloride and ligands in 1.2 M aqueous HCl were measured and by using
thermochemical cycles, the following thermochemical parameters for the adducts have been determined: the standard enthalpies
for the Lewis acid/base reactions (Δr
H
θ), the standard enthalpies of formation (Δf
H
θ), the lattice standard enthalpies (ΔM
H
θ), and the standard enthalpies of decomposition (ΔD
H
θ). 相似文献
8.
L. Peng X. Jiangjun M. Fangquan L. Xi Z. Chaocan 《Journal of Thermal Analysis and Calorimetry》2008,93(2):485-488
The standard molar enthalpy of combustion of cholesterol was measured at constant volume. According to value of Δr
U
mθ(−14358.4±20.65 kJ mol−1), Δr
H
mθ(−14385.7 kJ mol−1) of combustion reaction and Δf
H
mθ(2812.9 kJ mol−1) of cholesterol were obtained from the reaction equation. The enthalpy of combustion reaction of cholesterol was also estimated
by the average bond enthalpies. By design of a thermo-chemical recycle, the enthalpy of combustion of cholesterol were calculated
between 283.15∼373.15 K. Besides, molar enthalpy and entropy of fusion of cholesterol was obtained by DSC technique. 相似文献
9.
V. A. Luk’yanova T. S. Papina A. A. Gimadeev E. V. Sagadeev V. P. Barabanov 《Moscow University Chemistry Bulletin》2011,66(2):88-91
The energies of combustion, Δ
c
U
0, of three amino acids: L-serine (I), L-arginine (II) and L-tyrosine (III) in the crystalline state at 298.15 K were determined
using a static-bomb isoperibolic calorimeter. From these data, the enthalpies of combustion, Δ
c
H
0, and the enthalpies of formation, Δ
f
H
0, are calculated. The Δ
f
H
0 values are compared with the published data. 相似文献
10.
S. P. Chen S. L. Gao X. W. Yang Q. Z. Shi 《Russian Journal of Coordination Chemistry》2007,33(3):222-229
Thirteen solid ternary complexes Ln(Pdc)3(Phen) (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu;) have been synthesized in absolute ethanol by rare-earth
element chloride low hydrate reacting with the mixed ligands of ammonium pyrrolidinedithiocarbamate (APdc) and 1,10-phenanthroline
· H2O (o-Phen · H2O) in the ordinary laboratory atmosphere without any cautions against moisture or air sensitivity. IR spectra of the complexes
showed that the Ln3+ ion was coordinated with six sulfur atoms of three Pdc− and two nitrogen atoms of o-Phen · H2O. It was assumed that the coordination number of Ln3+ is eight. The constant-volume combustion energies of the complexes, Δc
U, were determined by a precise rotate-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, Δc
H
m
o
, and standard molar enthalpies of formation, Δf
H
m
o
were calculated.
The text was submitted by the authors in English. 相似文献
11.
Seven rare-earth complexes with salicylic acid RE(HSal)3·nH2O (HSal = C7H5O3; RE = La-Sm, n = 2; RE = Eu, Gd, n = 1) were synthesized and characterized by elemental analysis, the IR spectrum, and cyclic voltammetry. The constant-volume
combustion energies of complexes, Δc
U, were determined by a precise rotating-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, Δc
H
m
o
, and standard molar enthalpies of formation, Δf
H
m
o
, were calculated. 相似文献
12.
13.
The enthalpies of combustion (H
comb) of 13 primary, secondary, and tertiary alkylphoshines in the condensed state were calculated using the equation H
comb = –860.7 – 107.0N, where N is the number of valent (bond-forming) electrons. This equation can be used for the calculation of enthalpies of combustion and formation of phosphoric acid esters.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1693–1694, August, 2004. 相似文献
14.
Maria D. M. C. Ribeiro da Silva Joana I. T. A. Cabral Chelsea Givens Stephanie Keown W. E. Acree Jr. 《Journal of Thermal Analysis and Calorimetry》2008,92(1):73-78
The standard (p
0=0.1 MPa) molar enthalpies of formation, in the gaseous phase, at T-298.15 K, for 2,5-dimethylpyrazine (2,5-DMePz) and for the two dimethylpyrazine-N,N′-dioxide derivatives, 2,3-dimethylpyrazine-1,4-dioxide (2,3-DMePzDO) and 2,5-dimethylpyrazine-1,4-dioxide (2,5-DMePzDO), were
derived from the measurements of standard massic energies of combustion, using a static bomb calorimeter, and from the standard
molar enthalpies of vaporization or sublimation, measured by Calvet microcalorimetry.
The mean values for the molar dissociation enthalpy of the nitrogen-oxygen bonds, 〈DH
m0〉(N-O), were derived for both N,N′-dioxide compounds. These values are discussed in terms of the molecular structure of the two N,N′-dioxide derivatives and compared with 〈DH
m0〉(N-O) values previously obtained for other N-oxide derivatives. 相似文献
15.
A. I. Lytkin N. V. Chernyavskaya V. E. Litvinenko 《Russian Journal of Coordination Chemistry》2011,37(12):893-896
The enthalpies of complexation between N,N-bis(carboxymethyl)aspartic acid (H4Y) and the Pb2+ ion at 298.15 K were determined from calorimetric data for a wide range of the ionic strengths (KNO3). The thermodynamic characteristics ΔH, ΔG, and ΔS, of formation of the complexes PbHY− and PbY2− were calculated for zero and fixed ionic strengths. The results obtained were interpreted. 相似文献
16.
A combined method for determination of the standard enthalpies of formation of nitroform and its salts was proposed. The enthalpies
of dissolution of nitroform and its ammonium, hydrazinium, guanidinium, and potassium salts in water were measured. The enthalpy
of combustion of hydrazinium salt of nitroform was determined by a combustion calorimetry, and its standard enthalpy of formation
was calculated. The enthalpy of formation of trinitromethyl anion in indefinitely diluted aqueous solution −24.94±0.79 kJ
mol−1, was calculated on the basic of the data obtained for enthalpies of formation and dissolution of ammonium and hydrazinium
salts of nitroform. Standard enthalpies of formation of nitroform and its salts were calculated.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2451–2454, December, 1998. 相似文献
17.
The enthalpy of mixing of formamide,N-methylformamide,N,N-dimethylformamide, and hexamethylphosphoric triamide with MeCN was measured in the 283–328 K range. The enthalpic coefficients
of the binary and ternary interactions between the amide molecules are calculated within the framework of the McMillan-Mayer
theory. The contributions to the enthalpy of dissolution due to cavity formation in the solvent (Δcav
H
0) and due to solute-solvent interaction (Δint
H
0) were determined. The enthalpies of specific and nonspecific solvation of amides in MeCN were calculated. The main contribution
to the enthalpy of solvation of formamide andN-methylformamide is from specific interactions, while forN,N-dimethylformamide and hexamethylphosphoric triamide it is from nonspecific interactions. The values obtained are compared
with those for solutions of the amides mentioned in water and methanol.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1730–1735, October, 1993. 相似文献
18.
R. P. Tarasov A. V. Volkov M. I. Bazanov A. S. Semeikin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(5):868-869
The energy of combustion of cobalt tetrakis(4-metoxyphenyl)porphin was determined in an isothermic-shell liquid calorimeter
with a stationary calorimetric bomb. The standard enthalpies of combustion and formation of the complex were calculated, −Δ
c
H
o = 27334.06 ± 50.98 kJ/mol and Δf
H
o = 3062.90 ± 50.97 kJ/mol.
Original Russian Text ? R.P. Tarasov, A.V. Volkov, M.I. Bazanov, A.S. Semeikin, 2009, published in Zhurnal Fizicheskoi Khimii,
2009, Vol. 83, No. 5, pp. 993–995. 相似文献
19.
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
20.
Manuel A. V. Ribeiro da Silva Luísa M. P. F. Amaral 《Journal of Thermal Analysis and Calorimetry》2010,100(2):375-380
The standard (p
o = 0.1 MPa) molar enthalpies of formation
\Updelta\textf H\textm\texto ( \textl), {{\Updelta}}_{\text{f}} H_{\text{m}}^{\text{o}} ( {\text{l),}} of the liquid 2-methylfuran, 5-methyl-2-acetylfuran and 5-methyl-2-furaldehyde were derived from the standard molar energies
of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The Calvet high temperature vacuum sublimation technique was
used to measure the enthalpies of vaporization of the three compounds. The standard (p
o = 0.1 MPa) molar enthalpies of formation of the compounds, in the gaseous phase, at T = 298.15 K have been derived from the corresponding standard molar enthalpies of formation in the liquid phase and the standard
molar enthalpies of vaporization. The results obtained were −(76.4 ± 1.2), −(253.9 ± 1.9), and −(196.8 ± 1.8) kJ mol−1, for 2-methylfuran, 5-methyl-2-acetylfuran, and 5-methyl-2-furaldehyde, respectively. 相似文献