ISSN:
0009-2940
Keywords:
Gas-phase dissociation
;
Appearance energies
;
Calculations, AM1
;
Pyridinium cations, N-benzyl-2,4,6-substituted
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Collisionally activated dissociations (CADs) of various pyridine-ring substituted N-benzylpyridinium cations in the gas phase form the substituted pyridine and benzyl carbocation. Appearance energies (AEs) are estimated quantitatively from the appearance thresholds of the corresponding fragment ion from the laser-desorbed pyridinium cations. MO calculations predict that such unimolecular dissociation processes lead initially to ion-molecule pairs (IMPs): some such IMPs are of significantly lower energy than the fully dissociated products. The AEs have also been compared with the energy differences [ΔΔHf=ΔHf(Py) + ΔHf(R+) - ΔHf(Py+R)] determined by AM1 calculations: in many cases these are quite close to the calculated energy differences; discrepancies are discussed.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250129
