Standard molar enthalpies of formation of some methylfuran derivatives

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.     

Standard molar enthalpies of formation of some vinylfuran derivatives

The standard (p^° = 0.1 MPa) molar enthalpies of combustion, ${\mathrm{\Delta }}_{\text{c}}{H}_{\text{m}}^{°}$, for crystalline 2-furanacrylic acid, 3-furanacrylic acid, and 3-(2-furyl)-2-propenal and for the liquid 2-furanacrylonitrile were determined, at the temperature 298.15 K, using a static bomb combustion calorimeter. For these compounds, the standard molar enthalpies of phase transition, ${\mathrm{\Delta }}_{\text{cr,l}}^{\text{g}}{H}_{\text{m}}^{°}$, at T = 298.15 K, were determined by Calvet microcalorimetry. For the two crystalline furanacrylic acids the vapour pressures as function of temperature were measured by the Knudsen effusion technique and the standard molar enthalpies of sublimation, ${\mathrm{\Delta }}_{\text{cr}}^{\text{g}}{H}_{\text{m}}^{°}$, at T = 298.15 K were derived by the Clausius–Clapeyron equation. The results are as follows:     

4.

The standard enthalpies of formation of some dibenzoannelated cycloalkanols     

Stefan Perisanu  Mircea D. Banciu 《Thermochimica Acta》1998,320(1-2):9-12

The heats of combustion of trans-9,10-bis-hydroxymethyl-9,10-dihydrophenanthrene, trans-5-hydroxymethyl-5,6-dihydro-7H-dibenzo[a,c]cyclohepten-6-ol, 5-hydroxymethyl-5,6-dihydro-7H-di-benzo[a,c]cycloheptene, 6-hydroxymethyl-5,6-dihydro-7H-dibenzo[a,c]cycloheptene, 5H-dibenzo-[a,d]cyclohepten-5-ol and 5H-10,11-dihydrodibenzo[a,d]cyclohepten-5-ol were measured by means of a Gallenkamp adiabatic bomb calorimeter. Uncertainties in the determination of the heats of combustion ranged between 0.2 and 0.3%. The enthalpies of formation and atomization for the six compounds were derived. The experimental values of the heats of atomization were compared with those calculated using the Allen–Skinner bond energy scheme. Conclusions about energetic contributions which stabilize the structure of the investigated compounds were drawn.     

5.

Standard molar enthalpies of formation of 2-, 3- and 4-cyanobenzoic acids     

Manuel A.V. Ribeiro da Silva  Luísa M.P.F. Amaral  Cristina R.P. Boaventura  Jos R.B. Gomes 《The Journal of chemical thermodynamics》2008,40(8):1226-1231

The standard (p = 0.1 MPa) molar enthalpies of formation of 2-, 3- and 4-cyanobenzoic acids were derived from their 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 sublimation of 2- and 3-cyanobenzoic acids. The standard molar enthalpies of formation of the three compounds, in the gaseous phase, at T = 298.15 K, have been derived from the corresponding standard molar enthalpies of formation in the condensed phase and standard molar enthalpies for phase transition. The results obtained are −(150.7 ± 2.0) kJ · mol⁻¹, −(153.6 ± 1.7) kJ · mol⁻¹ and −(157.1 ± 1.4) kJ · mol⁻¹ for 2-cyano, 3-cyano and 4-cyanobenzoic acids, respectively. Standard molar enthalpies of formation were also estimated by employing two different methodologies: one based on the Cox scheme and the other one based on several different computational approaches. The calculated values show a good agreement with the experimental values obtained in this work.     

6.

Standard molar enthalpies of formation of some trichloroanilines by rotating-bomb calorimetry     

《The Journal of chemical thermodynamics》2002,34(1):119-127

The standard ( p^o =  0.1 MPa) molar enthalpies of formation Δ_fH_m^o, at the temperature 298.15 K, for crystalline 2,3,4-, 2,4,5-, 2,4,6- and 3,4,5-trichloroaniline were derived from the molar enthalpies of combustion Δ_cH_m^oin oxygen using rotating bomb combustion calorimetry. The reaction products were CO₂(g), N₂(g), and HCl · 600H₂O(l). The standard molar enthalpies of sublimation Δ_cr^gH_m^oat T =  298.15 K were measured by Calvet microcalorimetry. The results are as follows: The derived standard molar enthalpies of formation of the gaseous compounds were compared with values estimated by assuming the enthalpy increment for substitution of chlorine in aniline to be the same as for substitution into benzene.     

7.

Experimental measurements and a group additivity approach for estimating the standard molar enthalpies of formation of dioxins     

《Mendeleev Communications》1999,9(4):143-144

     

8.

Calorimetric determination of the standard molar enthalpies of formation of o-vanillin and trimethoprim     

Xu Li  Jian-Hong Jiang  Hui-Wen Gu  Sheng-Xiong Xiao  Chuan-Hua Li  Li-Juan Ye  Xia Li  Qiang-Guo Li  Fen Xu  Li-Xian Sun 《Journal of Thermal Analysis and Calorimetry》2015,119(1):721-726

     

9.

Experimental standard molar enthalpies of formation of crystalline 3,5-dimethylpyrazole, 3,5-dimethyl-4-nitrosopyrazole, 1,3,5-trimethyl-4-nitrosopyrazole,and 3,5-dimethyl-1-phenyl-4-nitrosopyrazole     

《The Journal of chemical thermodynamics》2001,33(10):1227-1235

The standard (p^o =  0.1 MPa) molar enthalpies of combustion in oxygen, at T =  298.15 K, for crystalline 3,5-dimethylpyrazole (Me₂Pyr), 3,5-dimethyl-4-nitrosopyrazole (Me₂PyrNO), 1,3,5-trimethyl-4-nitrosopyrazole (Me₃PyrNO), and 3,5-dimethyl-1-phenyl-4-nitrosopyrazole (Me₂PhPyrNO) were measured by static-bomb calorimetry. These values were used to derive the standard molar enthalpies of formation of the crystalline compounds. The standard molar enthalpies of sublimation for these four compounds were measured by microcalorimetry.The experimental results obtained allow us to derive the values of the standard molar enthalpies of formation, in the gaseous state, for the monomeric compounds involved in this work. These last values are discussed comparatively with results previously obtained for some aromatic nitroso derivatives.     

10.

Experimental and predicted excess molar enthalpies of some working pairs for absorption cycles     

Raouf Zehioua  Christophe Coquelet  Chien-Bin Soo  Dominique Richon  Abdeslam-Hassen Meniai 《Thermochimica Acta》2009,495(1-2):72-80

In this work, the measured excess molar enthalpies of absorption heat pump working pairs (refrigerant + absorbent), viz. water + mono-, di- and tri-ethylene glycol, water + glycerol, and ethanol + di- and tri-ethylene glycol mixtures are presented at 298.15 K and ambient pressure using a Setaram Calvet C80 calorimeter. The experimental results are represented and correlated by a Redlich–Kister type equation. Modeling of the excess enthalpies has been performed using the UNIFAC molecular group-contribution method, and UNIQUAC Gibbs energy model. In addition, the data and results are used to predict the Gibbs energy of all binary systems. This allows a preliminary evaluation of the suitability of the binary systems as heat pump working pairs.     

11.

Energies of combustion and standard molar enthalpies of formation of ricinoleic acid and methyl ricinoleate     

《The Journal of chemical thermodynamics》2012

     

12.

Standard molar enthalpies of formation of lithium alkoxides     

Jo  o Paulo Leal

J. A. Martinho Sim  es 《Journal of organometallic chemistry》1993,460(2):131-138

The standard (p⁰ = 0.1 MPa) molar enthalpies of formation of several crystalline lithium alkoxides, ΔH_f⁰(LiOR, cr), have been determined by reaction-solution calorimetry at 298.15 K. A linear correlation has been found between ΔH_f⁰(LiOR, cr) and ΔH_f⁰(ROH, 1) for R = n-alkyl, enabling the prediction of data for other lithium alkoxides. The deviations from the linear correlation observed for R =ⁱPr and ^tBu were tentatively explained in terms of the electronegativities of the OR groups. The experimental data were also used to derive the lattice energies and the thermochemical radii of the anions OR⁻. The results were compared with those derived from the enthalpies of formation of the analogous sodium alkoxides, reported in a previous publication.     

13.

Standard molar enthalpies of formation of sodium alkoxides     

《The Journal of chemical thermodynamics》2007,39(3):449-454

     

14.

Standard molar enthalpies of formation of monochloroacetophenone isomers     

Manuel A.V. Ribeiro da Silva  Luísa M.P.F. Amaral 《The Journal of chemical thermodynamics》2010,42(12):1473-1477

     

15.

Excess enthalpies and apparent molar volumes of some N-methyl substituted amino acids in aqueous solutions     

J. F. Reading  P. A. Carlisle  G. R. Hedwig  I. D. Watson 《Journal of solution chemistry》1989,18(2):131-142

The excess enthalpies and limiting partial molar volumes at 25°C for aqueous solutions of N-methyl glycine, N-methyl alanine, and N-methyl serine are reported and compared with the same properties for the parent amino acids. For each N-methyl derivative the enthalpic contribution to the pairwise interaction is less favorable than that for the parent amino acid. The contribution of the N-methyl substituent to V ₂ ⁰ is similar for each amino acid, and is about 2 cm³-mol^–1 greater than for a methyl substituent on the -carbon. These observations have been rationalized in terms of the likely solute-solvent interactions. In addition a rigid particle model is used with the volume data to examine solute-solvent interactions.     

16.

Standard molar enthalpies of formation of the acetylpyridine isomers     

《The Journal of chemical thermodynamics》2007,39(1):39-43

     

17.

Standard molar enthalpies of combustion of five trans -dimethoxycinnamic acids     

《The Journal of chemical thermodynamics》2001,33(8):899-903

The standard (p^o =  0.1 MPa) molar enthalpies of formation for 2,3-, 2,4-, 2,5-, 3,4- and 3,5- trans -dimethoxycinnamic acids, in the gaseous phase, were derived from the standard molar enthalpies of combustion in oxygen, of the crystalline compounds, determined by static bomb combustion calorimetry at T =  298.15 K and from the literature values for the respective enthalpies of sublimation.     

18.

The standard enthalpies of formation of alkoxy-NNO-azoxy compounds     

E. P. Kirpichev  I. N. Zyuzin  V. V. Avdonin  Yu. I. Rubtsov  D. B. Lempert 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(9):1359-1362

The standard enthalpies of combustion Δ_c H ^o and formation Δ_f H ^o of seven alkoxy-NNO-azoxy compounds containing the-N⁺(O^?)=NO-characteristic group were determined by combustion in a calorimetric bomb in the atmosphere of oxygen. The contribution of this group to the Δ_f H ^o enthalpies of the substances studied was calculated. The Δ_f H ^o enthalpies found by the method of group contributions were in satisfactory agreement with experimental data.     

19.

Synthesis,characterization and determination of standard molar enthalpies of formation of two copper borophosphates by solution calorimetry     

Guang-Hui Zhang 《Journal of Thermal Analysis and Calorimetry》2016,124(1):519-528

     

20.

Standard enthalpies of formation of some N-spiranes     

A. G. Korepin  A. I. Kazakov  N. A. Plishkin  O. G. Ivanova  L. S. Kurochkina  V. A. Garanin  V. P. Kosilko  D. A. Nesterenko 《Russian Chemical Bulletin》2011,60(9):1810-1813

The heats of combustion of three compounds, members of a new series of N-spiranes were measured by combustion calorimetry. The molecules of the title compounds comprise condensed and N-spirofused heterocycles as well as nitroxy groups that are both NO-donors and explosophores. The enthalpies of formation and the heats of explosive transformation of these compounds are calculated. Two compounds belong to explosives with low heat of explosive transformation, whereas the third compound is inert.     

The standard enthalpies of formation of some dibenzoannelated cycloalkanols

The heats of combustion of trans-9,10-bis-hydroxymethyl-9,10-dihydrophenanthrene, trans-5-hydroxymethyl-5,6-dihydro-7H-dibenzo[a,c]cyclohepten-6-ol, 5-hydroxymethyl-5,6-dihydro-7H-di-benzo[a,c]cycloheptene, 6-hydroxymethyl-5,6-dihydro-7H-dibenzo[a,c]cycloheptene, 5H-dibenzo-[a,d]cyclohepten-5-ol and 5H-10,11-dihydrodibenzo[a,d]cyclohepten-5-ol were measured by means of a Gallenkamp adiabatic bomb calorimeter. Uncertainties in the determination of the heats of combustion ranged between 0.2 and 0.3%. The enthalpies of formation and atomization for the six compounds were derived. The experimental values of the heats of atomization were compared with those calculated using the Allen–Skinner bond energy scheme. Conclusions about energetic contributions which stabilize the structure of the investigated compounds were drawn.     

Standard molar enthalpies of formation of 2-, 3- and 4-cyanobenzoic acids

The standard (p = 0.1 MPa) molar enthalpies of formation of 2-, 3- and 4-cyanobenzoic acids were derived from their 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 sublimation of 2- and 3-cyanobenzoic acids. The standard molar enthalpies of formation of the three compounds, in the gaseous phase, at T = 298.15 K, have been derived from the corresponding standard molar enthalpies of formation in the condensed phase and standard molar enthalpies for phase transition. The results obtained are −(150.7 ± 2.0) kJ · mol⁻¹, −(153.6 ± 1.7) kJ · mol⁻¹ and −(157.1 ± 1.4) kJ · mol⁻¹ for 2-cyano, 3-cyano and 4-cyanobenzoic acids, respectively. Standard molar enthalpies of formation were also estimated by employing two different methodologies: one based on the Cox scheme and the other one based on several different computational approaches. The calculated values show a good agreement with the experimental values obtained in this work.     

Standard molar enthalpies of formation of some trichloroanilines by rotating-bomb calorimetry

The standard ( p^o =  0.1 MPa) molar enthalpies of formation Δ_fH_m^o, at the temperature 298.15 K, for crystalline 2,3,4-, 2,4,5-, 2,4,6- and 3,4,5-trichloroaniline were derived from the molar enthalpies of combustion Δ_cH_m^oin oxygen using rotating bomb combustion calorimetry. The reaction products were CO₂(g), N₂(g), and HCl · 600H₂O(l). The standard molar enthalpies of sublimation Δ_cr^gH_m^oat T =  298.15 K were measured by Calvet microcalorimetry. The results are as follows: The derived standard molar enthalpies of formation of the gaseous compounds were compared with values estimated by assuming the enthalpy increment for substitution of chlorine in aniline to be the same as for substitution into benzene.     

Experimental standard molar enthalpies of formation of crystalline 3,5-dimethylpyrazole, 3,5-dimethyl-4-nitrosopyrazole, 1,3,5-trimethyl-4-nitrosopyrazole,and 3,5-dimethyl-1-phenyl-4-nitrosopyrazole

The standard (p^o =  0.1 MPa) molar enthalpies of combustion in oxygen, at T =  298.15 K, for crystalline 3,5-dimethylpyrazole (Me₂Pyr), 3,5-dimethyl-4-nitrosopyrazole (Me₂PyrNO), 1,3,5-trimethyl-4-nitrosopyrazole (Me₃PyrNO), and 3,5-dimethyl-1-phenyl-4-nitrosopyrazole (Me₂PhPyrNO) were measured by static-bomb calorimetry. These values were used to derive the standard molar enthalpies of formation of the crystalline compounds. The standard molar enthalpies of sublimation for these four compounds were measured by microcalorimetry.The experimental results obtained allow us to derive the values of the standard molar enthalpies of formation, in the gaseous state, for the monomeric compounds involved in this work. These last values are discussed comparatively with results previously obtained for some aromatic nitroso derivatives.     

Experimental and predicted excess molar enthalpies of some working pairs for absorption cycles

In this work, the measured excess molar enthalpies of absorption heat pump working pairs (refrigerant + absorbent), viz. water + mono-, di- and tri-ethylene glycol, water + glycerol, and ethanol + di- and tri-ethylene glycol mixtures are presented at 298.15 K and ambient pressure using a Setaram Calvet C80 calorimeter. The experimental results are represented and correlated by a Redlich–Kister type equation. Modeling of the excess enthalpies has been performed using the UNIFAC molecular group-contribution method, and UNIQUAC Gibbs energy model. In addition, the data and results are used to predict the Gibbs energy of all binary systems. This allows a preliminary evaluation of the suitability of the binary systems as heat pump working pairs.     

Standard molar enthalpies of formation of lithium alkoxides

The standard (p⁰ = 0.1 MPa) molar enthalpies of formation of several crystalline lithium alkoxides, ΔH_f⁰(LiOR, cr), have been determined by reaction-solution calorimetry at 298.15 K. A linear correlation has been found between ΔH_f⁰(LiOR, cr) and ΔH_f⁰(ROH, 1) for R = n-alkyl, enabling the prediction of data for other lithium alkoxides. The deviations from the linear correlation observed for R =ⁱPr and ^tBu were tentatively explained in terms of the electronegativities of the OR groups. The experimental data were also used to derive the lattice energies and the thermochemical radii of the anions OR⁻. The results were compared with those derived from the enthalpies of formation of the analogous sodium alkoxides, reported in a previous publication.     

Excess enthalpies and apparent molar volumes of some N-methyl substituted amino acids in aqueous solutions

The excess enthalpies and limiting partial molar volumes at 25°C for aqueous solutions of N-methyl glycine, N-methyl alanine, and N-methyl serine are reported and compared with the same properties for the parent amino acids. For each N-methyl derivative the enthalpic contribution to the pairwise interaction is less favorable than that for the parent amino acid. The contribution of the N-methyl substituent to V ₂ ⁰ is similar for each amino acid, and is about 2 cm³-mol^–1 greater than for a methyl substituent on the -carbon. These observations have been rationalized in terms of the likely solute-solvent interactions. In addition a rigid particle model is used with the volume data to examine solute-solvent interactions.     

Standard molar enthalpies of combustion of five trans -dimethoxycinnamic acids

The standard (p^o =  0.1 MPa) molar enthalpies of formation for 2,3-, 2,4-, 2,5-, 3,4- and 3,5- trans -dimethoxycinnamic acids, in the gaseous phase, were derived from the standard molar enthalpies of combustion in oxygen, of the crystalline compounds, determined by static bomb combustion calorimetry at T =  298.15 K and from the literature values for the respective enthalpies of sublimation.     

The standard enthalpies of formation of alkoxy-NNO-azoxy compounds

The standard enthalpies of combustion Δ_c H ^o and formation Δ_f H ^o of seven alkoxy-NNO-azoxy compounds containing the-N⁺(O^?)=NO-characteristic group were determined by combustion in a calorimetric bomb in the atmosphere of oxygen. The contribution of this group to the Δ_f H ^o enthalpies of the substances studied was calculated. The Δ_f H ^o enthalpies found by the method of group contributions were in satisfactory agreement with experimental data.     

Standard enthalpies of formation of some N-spiranes

The heats of combustion of three compounds, members of a new series of N-spiranes were measured by combustion calorimetry. The molecules of the title compounds comprise condensed and N-spirofused heterocycles as well as nitroxy groups that are both NO-donors and explosophores. The enthalpies of formation and the heats of explosive transformation of these compounds are calculated. Two compounds belong to explosives with low heat of explosive transformation, whereas the third compound is inert.