Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Microcanonical analysis of the kinetic method. The meaning of the "effective temperature"
Autore:
Ervin, KM;
Indirizzi:
Univ Nevada, Dept Chem, Reno, NV 89557 USA Univ Nevada Reno NV USA 89557Univ Nevada, Dept Chem, Reno, NV 89557 USA Univ Nevada, Chem Phys Program, Reno, NV 89557 USA Univ Nevada Reno NV USA 89557 vada, Chem Phys Program, Reno, NV 89557 USA
Titolo Testata:
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
, volume: 196, anno: 2000,
pagine: 271 - 284
SICI:
1387-3806(20000121)196:<271:MAOTKM>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
TANDEM MASS-SPECTROMETRY; GAS-PHASE; PROTON AFFINITIES; THERMOCHEMICAL DETERMINATIONS; ALCOHOLS; PAIR; IONS;
Keywords:
kinetic method; proton-bound dimers; microcanonical kinetic rate theory;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
34
Recensione:
Indirizzi per estratti:
Indirizzo: Ervin, KM Univ Nevada, Dept Chem, Reno, NV 89557 USA Univ Nevada Reno NV USA 89557 da, Dept Chem, Reno, NV 89557 USA
Citazione:
K.M. Ervin, "Microcanonical analysis of the kinetic method. The meaning of the "effective temperature"", INT J MASS, 196, 2000, pp. 271-284

Abstract

An analytical expression for the "effective temperature" parameter in the Cooks kinetic method is derived using classical Rice-Ramsperger-Kassel (RRK) theory for the microcanonical unimolecular dissociation rate. The approximate expression is appropriate for metastable ion dissociation experiments and high ion source temperatures. The effective temperature is directly proportional to the well depth (complexation energy) of the dissociating cluster ion, is inversely proportional to the number of oscillators of the cluster (vibrational degrees of freedom), and also depends on the product of thereaction frequency (preexponential factor) and the instrumental time window of the experiment. Numerical simulations using classical RRK rates with adetailed kinetics treatment are compared with the analytical expression for the effective temperatures. For fast dissociations (shallow cluster well depth or small number of oscillators), threshold effects cause significant curvature in the kinetic method plots. The implications of these results onthe accuracy of relative thermochemical measurements by the kinetic methodare discussed. (C) 2000 Elsevier Science B.V.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 10/07/20 alle ore 02:08:12