C2HD4+]
complexes are estimated to range from about 20 to 200 ps, depending on the
temperature.|
Lifetimes of Gaseous Ion-Neutral Complexes: The Rate of Isotopic Scrambling within Ethyl Ions as an Internal Clock |
| Massimiliano Aschi 1, Marina Attinā 2, Fulvio Cacace 1 * |
| 1Universitā di Roma La Sapienza, P. le
A. Moro, 5, I-00185 Rome (Italy), Fax: (+39) 6 4991-3602 2Universitā di Roma Tor Vergata, V. le della Ricerca Scientifica, I-00133 Rome (Italy), Fax: (+39) 6 7259-4328 |
| email: Marina Attinā (attinā@stc.uniroma2.it) Fulvio Cacace (cacace@uniroma1.it) |
*Correspondence to Fulvio Cacace,
1Universitā di Roma La Sapienza, P. le A. Moro, 5,
I-00185 Rome (Italy), Fax: (+39) 6 4991-3602
| Keywords |
| Automerizations Crafts-Friedel reactions Ion-neutral complexes Ion-molecule reactions Kinetics |
| Abstract |
| The theoretically computed rate of H/D scrambling within labeled
ethyl ions is used as a clock to time the lifetime of ion-neutral complexes,
previously characterized as the charged intermediates in gas-phase aromatic
alkylation. From experiments performed in the temperature interval from 298
to 393 K in CF4 at 720 Torr, the lifetimes of [CF3C6H5C2HD4+]
complexes are estimated to range from about 20 to 200 ps, depending on the
temperature. |
Received: 13 January 1998