Article (Scientific journals)
Ground and Excited State Dissociation Dynamics of Ionized 1,1-Difluoroethene
Gridelet, Evelyne; Dehareng, Dominique; Locht, Robert et al.
2005In Journal of Physical Chemistry. A, 109 (37), p. 8225-8235
Peer Reviewed verified by ORBi
 

Files


Full Text
JPCA109(2005)8225(pped).pdf
Publisher postprint (202.61 kB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
Kinetic energy release distributions; Dissociative photoionization; Two sector mass spectrometer; Maximum entropy method; Orbiting transition state theory; Ab initio calculations; Conical intersection; 1,1-C2H2F2
Abstract :
[en] The kinetic energy release distributions (KERDs) for the fluorine atom loss from the 1,1-difluoroethene cation have been recorded with two spectrometers in two different energy ranges. A first experiment uses dissociative photoionization with the He(I) and Ne(I) resonance lines, providing the ions with a broad internal energy range, up to 7 eV above the dissociation threshold. The second experiment samples the metastable range, and the average ion internal energy is limited to about 0.2 eV above the threshold. In both energy domains, KERDs are found to be bimodal. Each component has been analyzed by the maximum entropy method. The narrow, low kinetic energy components display for both experiments the characteristics of a statistical, simple bond cleavage reaction: constraint equal to the square root of the fragment kinetic energy and ergodicity index higher than 90%. Furthermore, this component is satisfactorily accounted for in the metastable time scale by the orbiting transition state theory. Potential energy surfaces corresponding to the five lowest electronic states of the dissociating 1,1-C2H2F2+ ion have been investigated by ab initio calculations at various levels. The equilibrium geometry of these states, their dissociation energies, and their vibrational wavenumbers have been calculated, and a few conical intersections between these surfaces have been identified. It comes out that the ionic ground state (X) over tilde B-2(1) is adiabatically correlated with the lowest dissociation asymptote. Its potential energy curve increases in a monotonic way along the reaction coordinate, giving rise to the narrow KERD component. Two states embedded in the third photoelectron band ( (B) over tilde (2)A(1), at 15.95 eV and (C) over tilde B-2(2) at 16.17 eV) also correlate with the lowest asymptote at 14.24 eV. We suggest that their repulsive behavior along the reaction coordinate be responsible for the KERD high kinetic energy contribution.
Research center :
Laboratoire de Dynamique Moléculaire
Disciplines :
Chemistry
Author, co-author :
Gridelet, Evelyne
Dehareng, Dominique ;  Université de Liège - ULiège > Centre d'ingénierie des protéines
Locht, Robert  ;  Université de Liège - ULiège > Département de Chimie (Faculté des Sciences) > Laboratoire de Dynamique Moléculaire (Sciences)
Lorquet, Andrée ;  Université de Liège - ULiège > Département de chimie (sciences) > Laboratoire de dynamique moléculaire
Lorquet, Jean-Claude ;  Université de Liège - ULiège > Département de Chimie (Faculté des sciences) > Laboratoire de Dynamique Moléculaire (Sciences)
Leyh, Bernard  ;  Université de Liège - ULiège > Département de chimie (sciences) > Laboratoire de dynamique moléculaire
Language :
English
Title :
Ground and Excited State Dissociation Dynamics of Ionized 1,1-Difluoroethene
Alternative titles :
[fr] Dynamique de la dissociation des états fondamental et excité du 1,1-difluoroéthylène ionisé.
Publication date :
2005
Journal title :
Journal of Physical Chemistry. A
ISSN :
1089-5639
eISSN :
1520-5215
Publisher :
Amer Chemical Soc, Washington, United States
Volume :
109
Issue :
37
Pages :
8225-8235
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
ARC Contract n°99/04-245, PAI Contract n°P4/03, FNRS
BELSPO - SPP Politique scientifique - Service Public Fédéral de Programmation Politique scientifique
Available on ORBi :
since 18 November 2008

Statistics


Number of views
110 (25 by ULiège)
Number of downloads
9 (9 by ULiège)

Scopus citations®
 
17
Scopus citations®
without self-citations
7
OpenCitations
 
16

Bibliography


Similar publications



Contact ORBi