Chaleurs de mélange du système éthyl-3 pentanol-3 tétrachlorure de carbone

1972 ◽  
Vol 50 (19) ◽  
pp. 3207-3211
Author(s):  
H. Brusset ◽  
M. Desgranges ◽  
J. C. Lecoq
Keyword(s):  
Hydrogen Bond ◽  
Carbon Tetrachloride ◽  
Enthalpy Of Formation ◽  
Infinite Dilution ◽  
Excess Enthalpy ◽  
Molar Fraction ◽  
Enthalpies Of Mixing ◽  
Associated Solutions ◽  
Classic Theory ◽  
The Enthalpy Of Formation

The enthalpies of mixing in the system 3-ethyl-3 pentanol–carbon tetrachloride were measured by microcalorimetry. The classic theory of associated solutions leads to an expression for the excess enthalpy which we have simplified by introducing the heat at infinite dilution for the alcohol. The resulting expression allows the enthalpy of formation of a hydrogen bond to be calculated using calorimetric and tonometric results. The calculations show that this enthalpy is independent of the concentration of the solution (up to 0.45 in molar fraction) and is in agreement with the literature.

The physical and thermodynamic properties of some associated solutions I. Dielectric constants and heats of mixing

1964 ◽  
Vol 277 (1370) ◽  
pp. 423-436 ◽  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Tetrachloride ◽  
Magnetic Resonance ◽  
Hydrogen Bonds ◽  
Excess Enthalpy ◽  
Liquid Mixtures ◽  
Dielectric Constants ◽  
Associated Solutions ◽  
Heats Of Mixing ◽  
Nuclear Magnetic Resonance Spectra

The dielectric constants of the liquid mixtures piperidine/tetrahydropyran, piperidine/cyclohexane, and tetrahydropyran/cyclohexane have been determined in the temperature range 20 to 60 °C. They have been used to evaluate kirkwood's g -factor for the last two systems, and for the tetrahydropyran/ cyclohexane system, dipoler contributions to the execss thermodynamic functions of mixing . which have also been calculated for the chloro form/carbon tetrachloride system. The heats of mixing of the above systems have been determined (at 20 °C) in order to compare the strengths of the various types of molecular interaction involved. All the mixtures are formed endothermally, suggesting that N — H . . .O hydrogen bonds formed in the first system are weaker than the N — H . . .N bonds solely present in the second, which has the largest excess enthalpy of the three systems. Nuclear magnetic resonance spectra have provided evidence of the formation of these hydrogen bonds.

Thermochemistry of Organic and Heteroorganic Species. Part IX. Photoionization Studies of Isomerization and Fragmentation of Polysubstituted Cyclopropenes: Phenyl-Substituted Cyclopropenes

2000 ◽  
Vol 6 (1) ◽  
pp. 53-64 ◽  
Author(s):  
V.V. Takhistov ◽  
I.N. Domnin ◽  
D.A. Ponomarev
Keyword(s):  
Mass Spectrometry ◽  
Enthalpy Of Formation ◽  
Good Alternative ◽  
Enthalpies Of Formation ◽  
Isodesmic Reactions ◽  
Ion Structure ◽  
Photoionization Mass Spectrometry ◽  
General Methodology ◽  
Fragment Ions ◽  
The Enthalpy Of Formation

Ionization and appearance energies of some fragment ions from 1,2,3-trimethy1-3-phenyl-, 3-methyl-1,2,3-triphenyl-, 1,2-diphenyl-3-methoxycarbonyl-, 1,2,3-triphenyl-3-methoxycarbonyl- and 1,3,3-triphenyl-2-methoxycarbonyl-cyclopropenes were measured by photoionization mass spectrometry. It was shown that in none of these compounds did the fragment ions possess the expected stable substituted cyclopropenium ion structure. Accordingly, possible schemes of molecular ion isomerization are given. The enthalpies of formation of nearly 50 substituted cyclopropenium ions, and ions of related structure, were estimated using series of isodesmic reactions. This publication, together with the previous works of the authors in this Journal, demonstrates the general methodology for estimation of the enthalpy of formation for even-electron ions. It is suggested that the present methodology can provide a good alternative to other estimation or computation procedures applied to the thermochemistry of ions.

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