Gas-phase basicities of amides and imidates. Estimation of protomeric equilibrium constants by the basicity method in the gas phase

1979 ◽  
Vol 101 (6) ◽  
pp. 1361-1368 ◽  
Author(s):  
Donald H. Aue ◽  
L. D. Betowski ◽  
William R. Davidson ◽  
Michael T. Bowers ◽  
Peter Beak ◽  
...  
Keyword(s):  
Gas Phase ◽  
Equilibrium Constants ◽  
Gas Phase Basicities

Gas Phase Basicities of Styrenes toward Trimethylsilyl Cation. Structure and Stability of Me3Si-Styrene+Complexes

1992 ◽  
Vol 21 (12) ◽  
pp. 2439-2442 ◽  
Author(s):  
Masaaki Mishima ◽  
Chul Hyun Kang ◽  
Mizue Fujio ◽  
Yuho Tsuno
Keyword(s):  
Gas Phase ◽  
Structure And Stability ◽  
Trimethylsilyl Cation ◽  
Gas Phase Basicities

Theoretical prediction of proton and electron affinities, gas phase basicities, and ionization energies of sulfinamides

2019 ◽  
Vol 31 (1) ◽  
pp. 411-421
Author(s):  
Masoumeh Ghahremani ◽  
Hamed Bahrami ◽  
Hamed Douroudgari ◽  
Morteza Vahedpour
Keyword(s):  
Theoretical Prediction ◽  
Gas Phase ◽  
Electron Affinities ◽  
Ionization Energies ◽  
Gas Phase Basicities

Hydrogen bonding in the gas phase: the thermodynamic properties of hydrogen fluoride-ether complexes and their far infrared spectra

1971 ◽  
Vol 322 (1548) ◽  
pp. 137-146 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Equilibrium Constants ◽  
Far Infrared ◽  
Methyl Ethyl ◽  
Rotational Contour ◽  
Stretching Vibration ◽  
Conformational Rearrangements ◽  
Far Infrared Spectra

The equilibrium constants of gas-phase complexes of HF with dimethyl, methyl ethyl and diethyl ether have been measured at several temperatures using the Benesi-Hildebrand approximation on the absorption band of the HF stretching vibration in the complex. From these, values of Δ H of — 43, — 38 and — 30 kJ mol -1 respectively, have been determined. They are interpreted in terms of conformational rearrangements of the ethers when they form hydrogen bonds. The far infrared spectra of the complexes with both HF and DF have also been recorded and in each case a band observed at around 180 cm -1 which is assigned to the intermolecular stretching mode of vibration. For the complex between HF and dimethyl ether a rotational contour has been observed at about 10 cm -1 .

Absolute gas-phase acidities of CH3NH2, C2H5NH2, (CH3)2 NH, and (CH3)3N

1976 ◽  
Vol 54 (10) ◽  
pp. 1624-1642 ◽  
Author(s):  
Gervase I. Mackay ◽  
Ronald S. Hemsworth ◽  
Diethard K. Bohme
Keyword(s):  
Equilibrium Constant ◽  
Gas Phase ◽  
Equilibrium Constants ◽  
Heats Of Formation ◽  
Molecular Orbital Calculations ◽  
Electron Affinities ◽  
Flowing Afterglow ◽  
Experimental Assessment ◽  
Gas Phase Acidity ◽  
Conjugate Bases

The flowing afterglow technique has been employed in measurements of the rate and equilibrium constants at 296 ± 2 K for reactions of the type[Formula: see text]and[Formula: see text]where R1 and R2 may be H, CH3, or C2H5. The equilibrium constant measurements provided absolute values for the intrinsic (gas-phase) acidities of the Brønsted acids CH3NH2, C2H5NH2, (CH3)2NH, and (CH3)3N, the heats of formation of their conjugate bases, and the electron affinities of the corresponding radicals R1R2N. Proton removal energies, ΔG0298/(kcal mol−1), were determined to be 395.7 ± 0.7 for [Formula: see text] 391.7 ± 0.7 for [Formula: see text] 389.2 ± 0.6 for [Formula: see text] and > 396 for [Formula: see text] Heats of formation, ΔH0f.,298, were determined to be 30.5 ± 1.5 for CH3NH−, 21.2 ± 1.5 for C2H5NH−, and 24.7 ± 1.4 for (CH3)2N−. Electron affinities (in kcal mol−1) were determined to be 13.1 ± 3.5 for CH3NH, 17 ± 4 for C2H5NH, and 14.3 ± 3.4 for (CH3)2N. These results quantify earlier conclusions regarding the intrinsic effects of substituents on the gas-phase acidity of amines and provide an experimental assessment of recent molecular orbital calculations of proton removal energies for alkylamines.

The sorption of krypton and xenon in zeolites at high pressures and temperatures I. Chabazite

1972 ◽  
Vol 326 (1566) ◽  
pp. 315-330 ◽  
Keyword(s):  
Gas Phase ◽  
Thermodynamic Equilibrium ◽  
High Pressures ◽  
Equilibrium Constants ◽  
Standard State ◽  
Temperature Range ◽  
Thermodynamic Relationship ◽  
High Pressures And Temperatures

Isotherms of Kr and Xe in chabazite have been obtained for absolute sorption and for Gibbs excess sorption, in the temperature range 150 to 450 °C and at pressures up to 100 atm. Thermodynamic equilibrium constants for distribution of gas between the crystals and the gas phase, standard state concentrations and heats of sorption have been determined. At the highest pressures differences between absolute sorption and Gibbs excess sorption were large. The change of equilibrium fugacity with temperature for given absolute and Gibbs excess sorptions yielded two differential heats of sorption and two differential entropies of the sorbate. These heats, and the corresponding entropies, differed numerically and in their dependence upon amount sorbed. The thermodynamic relationship between the two heats has been derived and discussed.

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