17000-00-9Relevant articles and documents
The Ionic Hydrogen Bond and Ion Solvation. 2. Solvation of Onium Ions by One to Seven H2O Molecules. Relations between Monomolecular, Specific, and Bulk Hydration
Meot-Ner (Mautner), Michael
, p. 1265 - 1272 (1984)
The relation between enthalpies of solvation of onium ions BH+ by one water molecule, -ΔHo0.1, and by four water molecules, -ΔHo0.4, is constant for most onium ions: ΔHo0.4/ΔHo0.1 is 2.8 +/- 0.1 for all oxonium ions and monoprotonic ammonium and pyridinium ions, and 3.1 +/- 0.1 for polyprotonic ammonium ions.These relations, in conjunction with the correlation between ΔHo0.1 and the proton affinity difference ΔPA = PA(B) - PA(H2O), allow the prediction of the total four-molecule specific hydration energy -ΔHo0.4 for all onium ions within the experimental accuracy of +/-3 kcal mol-1.The observed (or predicted) fourfold specific relative hydration energies simulate closely the relative bulk hydration enthalpies for most ions.In other words, for most onium ions differential hydration effects are determined by the specific hydrogen-bonding interactions.Deviations are useful to identify bulk solvation effects.For example, such deviations indicate attenuated bulk solvation of ions with phenyl substituents.
Kinetic and Theoretical Study on the Ion/Molecule Reactions of Methoxymethyl Cation with Ammonia
Okada, Satoshi,Abe, Yasuo,Taniguchi, Setsuo,Yamabe, Shinichi
, p. 295 - 300 (1987)
The reaction between C2H5O+ and NH3 is investigated by using the ion-trapping technique.Rate constants of reactions 3, 4, and 5 are determined.Their potential energy profiles are sought by use of the ab initio MO calculation.Reaction 3 gives the products methanol and protonated methylenimine.It is composed of the nucleophilic addition of NH3 to the carbonyl carbon and the subsequent 1,3-proton shift.Reaction 4 gives formaldehyde and protonated methylamine.It is of the SN2 type.Reaction 5 gives ammonium ion and ethylene oxide.The last reaction is of the specific pattern in the gas phase, although the reverse reaction involves the popular mechanism of the electrophilic ring cleavage.
Trends in alkyl substituent effects on nucleophilic reactions of carbonyl compounds: Gas phase reactions between ammonia and R1R2COCH3+ oxonium ions
Bache-Andreassen, Lihn,Uggerud, Einar
, p. 705 - 713 (2007/10/03)
The reactivity of carbonyl substituted methyl oxonium ions (R1R2COCH3-) towards ammonia has been investigated using an FT-ICR mass spectrometer and ab initio calculations. The monosubstituted ions (R1=H: R2 = H, CH3, C2H5 and i-C3H7) show different reaction patterns with variable degree of: (1) nucleophilic substitution, (2) addition elimination and (3) proton transfer, when reacted with ammonia. In all cases addition-elimination dominates over nucleophilic substitution, and the observed reactions are slow. The trends in reactivity are consistent with the alkyl group's electronic properties, as expressed by a single parameter linear or slightly non-linear model.
An ICR mass spectrometry study of ion/molecule reactions in mixtures of methylamine with ethylamine, propylamine, or butylamine
Xu, Guoying,Herman, Jan A.,Wojcik, Leszek
, p. 570 - 574 (2007/10/02)
Ion/molecule reactions of protonated alkylamine ion species, RNH3+, were studied in mixtures of methylamine with ethylamine, propylamine, or butylamine by ICR mass spectrometry at 1E-5 Torr.The occurrence of methyl group transfer from methylamine to higher protonated alkylamine species was observed.The rate constants of some bimolecular reactions occurring in these systems were estimated by numerical simulation.