Thermodynamics of Deuterium Exchange Reactions in Water-Thiol and Alcohol-Thiol Systems

1979 ◽  
Vol 32 (4) ◽  
pp. 755 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Thermodynamic Properties ◽  
Gas Phase ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Excess Enthalpies ◽  
Exchange Reactions ◽  
Gas Phase Reactions ◽  
Molar Excess ◽  
Harmonic Frequencies ◽  
Statistical Mechanical

Thermodynamic properties at 298 K are obtained for the deuterium exchange reactions RSH + SHD → O + RSD + H2O RSH + DO2 → O + RSD + HDO RSH + R?OD → O + RSD + R?OH Equilibrium constants and enthalpies of the gas phase reactions with R = R' = CH3 are calculated from statistical mechanical equations using recently published harmonic frequencies. Experimental properties, including the molar excess enthalpies of C2H5SH + CH3OH, C2H5SH + CH3OD, C2H5SH + C2H5OH and C2H5SH + C2H5OD reported in this paper, are used to obtain the equilibrium constants and enthalpies of the liquid and gas phase reactions with R = C2H5, R' = CH3 and C2H5.

Thermodynamics of deuterium exchange reactions in water-amine and alcohol-amine systems

1981 ◽  
Vol 34 (9) ◽  
pp. 1801
Author(s):  
ZS Kooner ◽  
DV Fenby
Keyword(s):  
Thermodynamic Properties ◽  
Equilibrium Constant ◽  
Deuterium Exchange ◽  
Excess Enthalpies ◽  
Exchange Reactions ◽  
Molar Excess ◽  
Harmonic Frequencies ◽  
Statistical Mechanical

Vapour pressures and molar excess enthalpies at 298.15 K are reported for the systems H2O+(C2H5)2NH and D2O+(C2H5)2NH. They are analysed to give the equilibrium constant and enthalpy of the reaction ����������������� 2(C2H5)2NH(1)+D2O(1)→2(C2H5)2ND(1)+H2O(1) Molar excess enthalpies at 298.15 K of the systems CH3OH+(C2H5)2NH, CH3OD+(C2H5)2NH, C2H5OH+(C2H5)2NH and C2H5OD+(C2H5)2NH are used to obtain enthalpies of the reactions ���������� (C2H5)2NH(1)+ROD(1)→(C2H5)2ND(1)+ROH(1)� (R = CH3, C2H5)Thermodynamic properties of various NH/OD exchange reactions are calculated from statistical mechanical equations by use of harmonic frequencies.

Determination of the equilibrium constants of water-methanol deuterium exchange reactions from vapour pressure measurements

1980 ◽  
Vol 33 (1) ◽  
pp. 9 ◽  
Author(s):  
ZS Koner ◽  
RC Phutela ◽  
DV Fenby
Keyword(s):  
Equilibrium Constant ◽  
Satisfactory Agreement ◽  
Vapour Pressure ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Pressure Measurements ◽  
Exchange Reactions ◽  
Molar Excess

The equilibrium constant of the reaction2CH3OH(l) + D2O(l) → 2CH3OD(l) + H2O(l) is obtained from vapour pressure measurements. The value, 1.09k0.02 at 298 K, is in satisfactory agreement with calculated values and with calorimetric estimates. Vapour pressures at 298.14 K are reported for the systems H2O + CH3OH, H2O+CH3OD, D2O + CH3OH and D2O+ CH3OD. Molar excess Gibbs functions are obtained from these vapour pressures.

Statistical Mechanics of Deuterium Exchange Reactions: Recalculation of Thermodynamic Properties of Water-Methanol Reactions

1979 ◽  
Vol 32 (3) ◽  
pp. 465 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Liquid Phase ◽  
Thermodynamic Properties ◽  
Force Field ◽  
Gas Phase ◽  
Vapour Pressure ◽  
The Other ◽  
Exchange Reactions ◽  
Statistical Mechanical ◽  
Experimental Values ◽  
Methanol Reactions

Thermodynamic properties of the reactions CH3OH+HDO → CH3D+H2O CH3OH+D2O → CH3OD+HDO in the gas phase are calculated from statistical mechanical equations. Two sets of calculated harmonic frequencies are used: one obtained from an experimental force field and the other from an ab initio force field. Thermodynamic properties of the corresponding liquid-phase reactions are obtained by combining the gas-phase values with vapour-pressure isotope effect results. The calculated properties are compared with published experimental values.

Deuterium exchange in water-methanol systems: Calculation of equilibrium constants

1977 ◽  
Vol 30 (11) ◽  
pp. 2371 ◽  
Author(s):  
DV Fenby
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Isotope Effects ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Exchange Reactions ◽  
Infrared Studies ◽  
Experimental Values ◽  
Calculated Equilibrium ◽  
Water Alcohol

Equilibrium constants for a number of water-alcohol deuterium exchange reactions in the gas phase are calculated from harmonic frequencies of CH3OH, CH3OD, CD3OH and CD3OD obtained from recent infrared studies. These are combined with vapour-pressure isotope effects to give equilibrium constants for the same reactions in the liquid phase. Calculated equilibrium constants agree well with most published experimental values.

Calorimetric study of deuterium isotope effects in water-acetone systems

1981 ◽  
Vol 34 (3) ◽  
pp. 635 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Isotope Effects ◽  
Exothermic Reaction ◽  
Deuterium Exchange ◽  
Calorimetric Study ◽  
Excess Enthalpies ◽  
Exchange Reactions ◽  
Molar Excess ◽  
Deuterium Isotope Effects

Molar excess enthalpies of H20 + (CH3),CO, H20 + (CD3),C0, D20 + (CH3)2C0 and D20+ (CD3)2CO at 298.15 K are reported and, in the case of the first system, compared with earlier studies. The results are comparable to those reported for deuterium isotope effects in the molar excess enthalpies of other systems containing (CH3)2CO and (CD3)2CO; they do not suggest the occurrence of any deuterium exchange reactions. A calorimetric study of the mixing of (CD3)2CO with H2O containing a small quantity of NaOH indicates the occurrence of slow, exothermic reaction(s).

Statistical mechanics of deuterium exchange reactions : relationships between equilibrium constants and enthalpies of reaction

1982 ◽  
Vol 35 (2) ◽  
pp. 237 ◽  
Author(s):  
DV Fenby ◽  
GL Bertrand
Keyword(s):  
Statistical Mechanics ◽  
Equilibrium Constant ◽  
Isotopic Exchange ◽  
Equilibrium Constants ◽  
Mechanical Analysis ◽  
Deuterium Exchange ◽  
Exchange Reactions ◽  
Statistical Mechanical

Bertrand and Burchfield proposed that the equilibrium constants K and the (standard) enthalpies ΔH of isotopic exchange reactions are related by the equation K = Kstatexp(-ΔH/RT) in which Kstat is the statistical (random) equilibrium constant. The application of this equation to deuterium exchange reactions for which experimental K and ΔH values are available suggests that it is a good approximation at 298 K. In this paper we present a statistical mechanical analysis to account for the success of the equation and to point out its limitations.

Vapour Pressure Study of Deuterium Exchange Reactions in Water-Ethanol Systems: Equilibrium Constant Determination

1979 ◽  
Vol 32 (11) ◽  
pp. 2353 ◽  
Author(s):  
RC Phutela ◽  
ZS Kooner ◽  
DV Fenby
Keyword(s):  
Liquid Phase ◽  
Equilibrium Constant ◽  
Vapour Pressure ◽  
Equilibrium Constants ◽  
Deuterium Exchange ◽  
Pressure Measurements ◽  
Exchange Reactions ◽  
Molar Excess ◽  
Constant Determination

A method is proposed for the determination of the equilibrium constants of liquid-phase deuterium exchange reactions from vapour pressure measurements. It is applied to water-ethanol systems to give the equilibrium constant of the reaction 2C2H5OH(l) + D2(l) → 2C2H5OD(l) + H2O(l) The value obtained, 1.05+0.02 at 298 K, is significantly greater than the 'random' value and is more precise and reasonable than a recent calorimetric estimate. Vapour pressures at 298.14 K are reported for the systems H2O+C2H5OH, H2O+C2H5OD, D2O + C2H5OH and D2O + C2H5OD. Molar excess Gibbs functions are obtained from these vapour pressure measurements.

Aromatic fluorocarbon mixtures. VI. Vapour pressures of carbon tetrachloride + hexafluorobenzene

1974 ◽  
Vol 27 (10) ◽  
pp. 2159 ◽  
Author(s):  
NF Pasco ◽  
DV Fenby
Keyword(s):  
Carbon Tetrachloride ◽  
Thermodynamic Properties ◽  
Equations Of State ◽  
Liquid Mixture ◽  
Excess Enthalpies ◽  
Molar Excess ◽  
Mixture Theories

Measurements are reported of the vapour pressures of the system carbon tetrachloride + hexafluorobenzene at 278.68 K. The molar excess Gibbs functions GE/M, obtained from these measurements have been combined with previously reported molar excess enthalpies to give GE/M at 298 K. Thermodynamic properties of CCl4+C6F6 at 298 K are compared with the predictions of liquid mixture theories based on analytic equations of state.

Hydrogen-deuterium exchange reactions of carbanions with deuterated alcohols in the gas phase

1978 ◽  
Vol 100 (9) ◽  
pp. 2921-2922 ◽  
Author(s):  
C. H. DePuy ◽  
Veronica M. Bierbaum ◽  
Gary K. King ◽  
R. H. Shapiro
Keyword(s):  
Gas Phase ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Exchange Reactions ◽  
Hydrogen Deuterium
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