Unstable enols in the gas phase. Preparation ionization, energies, and heats of formation of (E)- and (Z)-2-buten-2-ol, 2-methyl-1-propen-1-ol, and 3-methyl-2-buten-2-ol

1988 ◽  
Vol 110 (24) ◽  
pp. 7984-7990 ◽  
Author(s):  
Frantisek. Turecek ◽  
Libor. Brabec ◽  
Jorma. Korvola
Keyword(s):  
Gas Phase ◽  
Heats Of Formation ◽  
Ionization Energies

Sulfenic acids in the gas phase. Preparation, ionization energies and heats of formation of methane-, ethene-, and benzenesulfenic acid

1988 ◽  
Vol 53 (9) ◽  
pp. 2140-2158 ◽  
Author(s):  
František Tureček ◽  
Libor Brabec ◽  
Tomáš Vondrák ◽  
Vladimír Hanuš ◽  
Josef Hájíček ◽  
...  
Keyword(s):  
Experimental Data ◽  
Gas Phase ◽  
Radical Cations ◽  
Appearance Energy ◽  
Heats Of Formation ◽  
Ionization Energies ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Mndo Calculations ◽  
Sulfenic Acids

Methane-, ethene-, and ethynesulfenic acids were generated in the gas phase by flash-vacuum pyrolysis of the corresponding tert-butyl sulfoxides at 400 °C and 10-4 Pa. Benzenesulfenic acid was prepared from phenyl 3-buten-1-yl sulfoxide at 350 °C and 10-4 Pa. The sulfenic acids were characterized by mass spectrometry Threshold ionization energies (IE) were measured as IE(CH3SOH) = 9·07 ± 0·03 eV, IE(CH2=CHSOH) = 8·70 ± 0·03 eV, IE(HCCSOH) = 8·86 ± 0·04 eV, and IE(C6H5SOH) = 8·45 + 0·03 eV. Radical cations [CH3SOH].+, [CH2=CHSOH].+, and [HCCSOH].+ were generated by electron-impact-induced loss of propene from the corresponding propyl sulfoxides and their heats of formation were assessed by appearance energy measurements as 685, 824, and 927 kJ mol-1, respectively. Heats of formation of the neutral sulfenic acids and the S-(O) (C), S-(O) (Cd), S-(O) (Ct) and S-(O) (CB) group equivalents were determined. The experimental data, supported by MNDO calculations, point to sulfenate-like structures (R-S-OH) for the sulfenic acids under study.

Ionized ethylidene ketene and its homologue methylene ketene

1983 ◽  
Vol 61 (8) ◽  
pp. 1722-1724 ◽  
Author(s):  
Johan K. Terlouw ◽  
John L. Holmes ◽  
F. P. Lossing
Keyword(s):  
Mass Spectrum ◽  
Gas Phase ◽  
Collisional Activation ◽  
Heats Of Formation ◽  
Ionization Energies ◽  
Molecular Ion

The gas phase pyrolyses of crotonic and acrylic-trifluoroacetic anhydrides were shown to yield ethylidene ketene [CH3CH=C=C=O] and methylene ketene [CH2=C=C=O], respectively. The former was identified via the collisional activation mass spectrum of its molecular ion. The ionization energies of the two ketenes, 8.68 and 9.12 ± 0.05 eV respectively, measured using energy selected electrons, lead to 215 and 233 kcal mol−1 for their ionic heats of formation.

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

Synthesis and hydrolysis of gas-phase lanthanide and actinide oxide nitrate complexes: a correspondence to trivalent metal ion redox potentials and ionization energies

2015 ◽  
Vol 17 (15) ◽  
pp. 9942-9950 ◽  
Author(s):  
Ana F. Lucena ◽  
Célia Lourenço ◽  
Maria C. Michelini ◽  
Philip X. Rutkowski ◽  
José M. Carretas ◽  
...  
Keyword(s):  
Gas Phase ◽  
Metal Ion ◽  
Oxidation States ◽  
Redox Potentials ◽  
Trivalent Metal ◽  
Ionization Energies ◽  
Reduction Potentials ◽  
Hydrolysis Of ◽  
Nitrate Complexes

Gas-phase hydrolysis of lanthanide/actinide MO3(NO3)3−ions relates to the stabilities of the MIVoxidation states, which correlate with IV/III solution reduction potentials and 4th ionization energies.

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.

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