Determination of kinetics and equilibria of heterogeneously catalyzed gas-phase reactions in gradientless autoclave reactors by using the total pressure method: Methanol synthesis

The technique outlined in part I of this paper has been employed to study the photosensitized decomposition of acetone vapour. A theoretical interpretation of the non-stationary state applied to non-chain photochemical gas phase reactions with second-order termination has been given and the effects of non-homogeneous absorption of radiation have been considered. A value has been obtained for the rate constant for the recombination of methyl radicals in the gas phase at room temperature.

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The reaction of methylene radicals with methyl isocyanide

Canadian Journal of Chemistry ◽

10.1139/v79-200 ◽

1979 ◽

Vol 57 (10) ◽

pp. 1229-1232 ◽

Cited By ~ 1

Author(s):

Marsha T. J. Glionna ◽

Huw O. Pritchard

Keyword(s):

Gas Phase ◽

Exploratory Study ◽

Total Pressure ◽

Reaction Pathway ◽

Gas Phase Reactions ◽

Vibrationally Excited ◽

Methyl Cyanide ◽

Isotopic Studies ◽

Methyl Isocyanide ◽

Approximate Rate

An exploratory study has been made of the gas-phase reactions of methylene radicals, generated by the photolysis of ketene near 3000 Å, with methyl, ethyl, and allyl isocyanides at room temperature.With methyl isocyanide, the principal product at low pressure is ethyl cyanide, together with a few percent of methyl cyanide; ethyl isocyanide is also formed, increasingly so as the total pressure is increased. Reaction appears to take place through a vibrationally excited ethyl isocyanide intermediate, and approximate rate constants for each reaction pathway are derived. Isotopic studies suggest that the methylene radicals insert in the H3C—NC bond of the methyl isocyanide.

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The Hydrogen Bond Energies in ClHCl− and Cl−(HCl)n

Canadian Journal of Chemistry ◽

10.1139/v74-357 ◽

1974 ◽

Vol 52 (13) ◽

pp. 2449-2453 ◽

Cited By ~ 25

Author(s):

R. Yamdagni ◽

P. Kebarle

Keyword(s):

Gas Phase ◽

Equilibrium Constants ◽

Bond Energies ◽

Gas Phase Reactions ◽

Weakly Bound ◽

Pulsed Electron Beam ◽

Large N ◽

Different Temperatures ◽

Hydrogen Bond Energies

The equilibrium constants for the gas phase reactions: Cl−(HCl)n = Cl−(HCl)n−1 + HCl, (n, n−1) were measured at different temperatures with a pulsed electron beam high pressure mass spectrometer. This allowed determination of ΔGn,n−10, ΔHn,n−10, and ΔSn,n−10 for reactions with n = 1 to n = 4. The enthalpy change for the reaction: (ClHCl)− = Cl− + HCl was ΔH1.00 = 23.7 kcal/mol. This value is much higher than the literature value of 14.2 kcal/mol based on Born cycles. The stabilities of the Cl−(HCl)n clusters are compared with those of OH−(H2O)n and Cl−(H2O)n measured earlier. It is found that the (ClHCl)− is nearly as stable as the (HOHOH)− species but that the stabilities of the higher Cl−(HCl)n clusters decreases much more rapidly than that of OH−(H2O)n. The initial strong interaction in (ClHCl) is assumed to be due to the high polarizability of Cl. For large n this effect becomes unimportant. Cl−HOH is much more weakly bound than (ClHCl)−, however, at high n the Cl−(H2O)n interactions become more favorable.

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