The Extent of Non–Born-Oppenheimer Coupling in the Reaction of Cl(2P) with para-H2
Xingan Wang,1
Wenrui Dong,1
Chunlei Xiao,1
Li Che,1
Zefeng Ren,1
Dongxu Dai,1
Xiuyan Wang,1
Piergiorgio Casavecchia,1*
Xueming Yang,1
Bin Jiang,2
Daiqian Xie,2,3
Zhigang Sun,1,4
Soo-Y. Lee,4
Dong H. Zhang,1
Hans-Joachim Werner,5
Millard H. Alexander6
Elementary triatomic reactions offer a compelling test of our
understanding of the extent of electron-nuclear coupling in
chemical reactions, which is neglected in the widely applied
Born-Oppenheimer (BO) approximation. The BO approximation predicts
that in reactions between chlorine (Cl) atoms and molecular
hydrogen, the excited spin-orbit state (Cl*) should not participate
to a notable extent. We report molecular beam experiments, based
on hydrogen-atom Rydberg tagging detection, that reveal only
a minor role of Cl*. These results are in excellent agreement
with fully quantum-reactive scattering calculations based on
two sets of ab initio potential energy surfaces. This study
resolves a previous disagreement between theory and experiment
and confirms our ability to simulate accurately chemical reactions
on multiple potential energy surfaces.
2 Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China.
3 Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
4 School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
5 Institute für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
6 Department of Chemistry and Biochemistry and Institute for Physical Sciences and Technology, University of Maryland, College Park, MD 20742–2021, USA.
* Present address: Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy.
To whom correspondence should be addressed. E-mail: xmyang{at}dicp.ac.cn (X.Y.), dqxie{at}mail.nju.edu.cn (D.X.), zhangdh{at}dicp.ac.cn (D.H.Z.), and mha{at}umd.edu (M.H.A.)
