Transmission Coefficients for Chemical Reactions with Multiple States: Role of Quantum Decoherence.
Transition-state theory (TST) is a widely accepted paradigm for rationalizing the kinetics of chemical reactions involving one potential energy surface (PES). Multiple PES reaction rate constants can also be estimated within semiclassical approaches provided the hopping probability between the quant...
| Publicado en: | Journal of the American Chemical Society Vol. 133; no. 11; pp. 3883 - 3895 |
|---|---|
| Autores principales: | , , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
3/23/2011
|
| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=63149561&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 63149561 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 3/23/2011 vid: 133 iid: 11 pid: 997 pub: American Chemical Society artinfo: ui: 63149561 10.1021/ja107950m ppf: 3883 ppct: 12 formats: tig: atl: Transmission Coefficients for Chemical Reactions with Multiple States: Role of Quantum Decoherence. aug: au: de la Lande, Aurélien Řezáč, Jan Lévy, Bernard Sanders, Barry C. Salahub, Dennis R. affil: Laboratoire de Chimie Physique-CNRS UMR 8000, Université Paris-Sud 11, Bât. 349, Campus d'Orsay, 15 rue Jean Perrin, 91 405 Orsay Cedex, France Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nam. 2, 166 10 Prague 6, Czech Republic Institute for Quantum Information Science, University of Calgary, 2500 University Drive, Calgary, Canada T2N 1N4 Department of Chemistry, Institute for Biocomplexity and Informatics, and Institute for Sustainable Energy, Environment and Economy, University of Calgary, 2500 University Drive, Calgary, Canada T2N 1N4 su: Chemical reactions Dynamics Potential energy surfaces Charge exchange Monooxygenases Quantum chemistry sug: subj: Chemical reactions Dynamics Potential energy surfaces Charge exchange Monooxygenases Quantum chemistry ab: Transition-state theory (TST) is a widely accepted paradigm for rationalizing the kinetics of chemical reactions involving one potential energy surface (PES). Multiple PES reaction rate constants can also be estimated within semiclassical approaches provided the hopping probability between the quantum states is taken into account when determining the transmission coefficient. In the Marcus theory of electron transfer, this hopping probability was historically calculated with models such as Landau-Zener theory. Although the hopping probability is intimately related to the question of the transition from the fully quantum to the semiclassical description, this issue is not adequately handled in physicochemical models commonly in use. In particular, quantum nuclear effects such as decoherence or dephasing are not present in the rate constant expressions. Retaining the convenient semiclassical picture, we include these effects through the introduction of a phenomenological quantum decoherence function. A simple modification to the usual TST rate constant expression is proposed: in addition to the electronic coupling, a characteristic decoherence time τ now also appears as a key parameter of the rate constant. This new parameter captures the idea that molecular systems, although intrinsically obeying quantum mechanical laws, behave semiclassically after a finite but nonzero amount of time (τ). This new degree of freedom allows a fresh look at the underlying physics of chemical reactions involving more than one quantum state. The ability of the proposed formula to describe the main physical lines of the phenomenon is confirmed by comparison with results obtained from density functional theory molecular dynamics simulations for a triplet to singlet transition within a copper dioxygen adduct relevant to the question of dioxygen activation by copper monooxygenases. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2011 holdings: @attributes: islocal: N |
|---|