There is no general picture to describe the influences of reagent rotational excitation on the reaction,which proceeds via the tunnelling mechanism at collision energies far below the reaction barrier.Here we report a...There is no general picture to describe the influences of reagent rotational excitation on the reaction,which proceeds via the tunnelling mechanism at collision energies far below the reaction barrier.Here we report a crossed beam study on the prototypical reaction of F+D_(2)(v=0,j=0,1)→DF(v′)+D at collision energies between 44 and 164 cm^(-1)with the scheme of multichannel D-atom Rydberg tagging time-of-flight detection.Vibrational state resolved differential cross sections are obtained at v′=2,3,4 levels.The effects of reagent rotational excitation were investigated at an equivalent amount of total energy by precise tuning of translational energies.Compared with translation,the rotation of D_(2) is found to be more efficient to promote the title reaction.Profound differences introduced by rotation of D_(2) are also observed on the angular distribution and quantum state distribution of DF products.We hope the present work could provide an example for understanding the effects of reagent rotational excitation on the chemical reaction at energies that are much lower than the reaction barrier.展开更多
Quasiclassical trajectory calculation of the title reaction O（^3P）＋H2→OH＋H at three different scattering energies of 0.5, 0.75, and 1.0 eV on the lowest electronic potential energy surface 1^3A＂ has been done. D...Quasiclassical trajectory calculation of the title reaction O（^3P）＋H2→OH＋H at three different scattering energies of 0.5, 0.75, and 1.0 eV on the lowest electronic potential energy surface 1^3A＂ has been done. Distribution P（θr） of polar angles between the relative velocityk of the reactant and rotational angular momentum vector j＇ of the product, distribution P（φr） of the azimuthal as well as dihedral angles correlating k-k＇-j＇, 3-dimensional distri-bution, and polarization-dependent differential cross sections （PDDCSs）dependent upon the scattering angle of the product molecule OH between the relative velocity k of the reactant and k＇ of the product at different scattering energies of 0.5, 0.75, and 1.0 eV are presented and discussed.展开更多
Quasi-classical trajectory calculations are performed to study the stereodynamics of the H（~2S） ＋ NH（a^1？） →H_2（X^1Σ_g~＋） ＋ N（~2D） reaction based on the first excited state NH_2（1~2A＇） potential energ...Quasi-classical trajectory calculations are performed to study the stereodynamics of the H（~2S） ＋ NH（a^1？） →H_2（X^1Σ_g~＋） ＋ N（~2D） reaction based on the first excited state NH_2（1~2A＇） potential energy surface reported by Li et al.[Li Y Q and Varandas A J C 2010 J. Phys. Chem. A 114 9644] for the first time. We observe the changes of differential cross-sections at different collision energies and different initial reagent rotational excitations. The influence of collision energy on the k-k＇ distribution can be attributed to a purely impulsive effect. Initial reagent rotational excitation transforms the reaction mechanism from insertion to abstraction. The effect of initial reagent rotational excitations on k-k＇ distribution can be explained by the rotational excitation enlarging the rotational rate of reagent NH in the entrance channel to reduce the probability of collision between incidence H atom and H atom of target molecular. We also investigate the changes of vector correlations and find that the rotational angular momentum vector j＇ of the product H_2 is not only aligned, but also oriented along the y axis. The alignment parameter, the disposal of total angular momentum and the reaction mechanism are all analyzed carefully to explain the polarization behavior of the product rotational angular moment.展开更多
基金supported by the National Natural Science Foundation of China(No.21822305,No.21688102,No.22003067)the Chinese Academy of Sciences(No.XDB17000000)。
文摘There is no general picture to describe the influences of reagent rotational excitation on the reaction,which proceeds via the tunnelling mechanism at collision energies far below the reaction barrier.Here we report a crossed beam study on the prototypical reaction of F+D_(2)(v=0,j=0,1)→DF(v′)+D at collision energies between 44 and 164 cm^(-1)with the scheme of multichannel D-atom Rydberg tagging time-of-flight detection.Vibrational state resolved differential cross sections are obtained at v′=2,3,4 levels.The effects of reagent rotational excitation were investigated at an equivalent amount of total energy by precise tuning of translational energies.Compared with translation,the rotation of D_(2) is found to be more efficient to promote the title reaction.Profound differences introduced by rotation of D_(2) are also observed on the angular distribution and quantum state distribution of DF products.We hope the present work could provide an example for understanding the effects of reagent rotational excitation on the chemical reaction at energies that are much lower than the reaction barrier.
文摘Quasiclassical trajectory calculation of the title reaction O（^3P）＋H2→OH＋H at three different scattering energies of 0.5, 0.75, and 1.0 eV on the lowest electronic potential energy surface 1^3A＂ has been done. Distribution P（θr） of polar angles between the relative velocityk of the reactant and rotational angular momentum vector j＇ of the product, distribution P（φr） of the azimuthal as well as dihedral angles correlating k-k＇-j＇, 3-dimensional distri-bution, and polarization-dependent differential cross sections （PDDCSs）dependent upon the scattering angle of the product molecule OH between the relative velocity k of the reactant and k＇ of the product at different scattering energies of 0.5, 0.75, and 1.0 eV are presented and discussed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474141and 11274149)the Program for Liaoning Excellent Talents in University,China(Grant No.LJQ2015040)+2 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,China(Grant No.2014-1685)the Special Fund Based Research New Technology of Methanol Conversion and Coal Instead of Oilthe China Postdoctoral Science Foundation(Grant No.2014M550158)
文摘Quasi-classical trajectory calculations are performed to study the stereodynamics of the H（~2S） ＋ NH（a^1？） →H_2（X^1Σ_g~＋） ＋ N（~2D） reaction based on the first excited state NH_2（1~2A＇） potential energy surface reported by Li et al.[Li Y Q and Varandas A J C 2010 J. Phys. Chem. A 114 9644] for the first time. We observe the changes of differential cross-sections at different collision energies and different initial reagent rotational excitations. The influence of collision energy on the k-k＇ distribution can be attributed to a purely impulsive effect. Initial reagent rotational excitation transforms the reaction mechanism from insertion to abstraction. The effect of initial reagent rotational excitations on k-k＇ distribution can be explained by the rotational excitation enlarging the rotational rate of reagent NH in the entrance channel to reduce the probability of collision between incidence H atom and H atom of target molecular. We also investigate the changes of vector correlations and find that the rotational angular momentum vector j＇ of the product H_2 is not only aligned, but also oriented along the y axis. The alignment parameter, the disposal of total angular momentum and the reaction mechanism are all analyzed carefully to explain the polarization behavior of the product rotational angular moment.
