Recently, Yang Xueming, an academician of the Chinese Academy of Sciences and a researcher at the National Key Laboratory of Molecular Reaction Kinetics of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and Sun Zhigang, a researcher at the Dalian Institute of Chemical Physics, cooperated with Wang Xing'an, a professor at the University of Science and Technology of China to study the dynamics of the F+HD reaction with wave division resonance in detail, and for the first time, the influence of electron angular momentum on the differential cross-section of chemical reactions was discovered.
Molecular reaction kinetics is a discipline that studies the dynamic process of chemical reactions at the microscopic level. The combination of the results of the cross-molecular beam experimental device and the theoretical simulation of quantum molecular dynamics is the basic means to study the dynamic process of chemical reactions. Under the condition that a chemical reaction occurs in a single collision, the cross-molecular beam device can detect chemical reaction products with vibration-spinning state resolution; based on the construction of high-precision potential energy surfaces, the simulation of quantum chemical dynamics theory can calculate the scattering information of chemical reactions with quantum state resolution under a single collision.
After long-term development, the resolution of the cross-molecular beam experimental device has been greatly improved. In 1986, Nobel Prize winner in Chemistry and Professor Li Yuanzhe developed the typical universal cross-molecular beam experimental device at that time, which had the resolution of product vibration, so he was able to conduct detailed research on the reactions of F+H2 and its isotopes for the first time. The cross-molecular beam ion imaging device developed in the 1990s expanded the research object of the cross-molecular beam device from a triatomic reaction system to a multi-atomic reaction system under conditions with vibrational dynamic resolution. In addition, the time-fly spectroscopy technology of hydrogen atom Reedburg state identification has been developed almost simultaneously to increase the resolution of the cross-molecular beam device to the rotational dynamics of the product. Using such a high-resolution experimental setup and precise quantum dynamics theoretical research, images of the resonant states of the reactions in F+H2 and its isotope reactions are clearly explained. In recent years, Yang Xueming and Wang Xing'an have further developed cross-molecular beam ion imaging devices to increase the resolution of the detection products to the rotational dynamics of the products. Using this experimental device, combined with the newly developed quantum dynamics theoretical analysis methods, the existence of quantum geometric phase effects in chemical reactions was confirmed for the first time in 2018 (Science, 2018). So far, the research on chemical reaction dynamics has undergone the development from product quantum vibration dynamic resolution to rotational dynamic resolution. But in order to study the dynamics of chemical reactions at a more microscopic level, such as studying how electron angular momentum and even nucleus spin angular momentum affect the dynamics of chemical reactions, it will be another landmark progress in the study of chemical reactions.
F+HD reaction is a very special reaction, which has obvious wave division resonance effect. A high-resolution reaction kinetic study is carried out on this reaction, and it is possible to discover the impact of electron angular momentum on chemical reactions. Yang Xueming and Wang Xing'an used their cross-molecular beam ion imaging device to combine the quantum dynamics theoretical simulation method developed by Sun Zhigang that considers the electron angular momentum effect, and studied the dynamics of the F+HD reaction with divided wave resonance in detail: the special wave-dividing resonance phenomenon in this reaction can be used to reveal the impact of the electron angular momentum of the F atom on the reaction process; its manifestation is that after considering the electron angular momentum effect of the F atom, a single wave-dividing resonance can become a wave-dividing resonance with a quadruple fine structure, thereby changing the angular distribution of the chemical reaction products. This change is very subtle and can only be observed by a high-resolution cross-molecular beam imaging device. The relevant research results of
were published in Science on February 26, Beijing time. The four judges of the paper unanimously agreed that the research work was excellent and praised it as a textbook example-level research result. The research work has been funded by the National Natural Science Foundation of China and the Strategic Leading Science and Technology Special Project (Class B) of the Chinese Academy of Sciences.
Chinese scientists discovered the effect of electron angular momentum on differential cross-section of chemical reactions
Source: Dalian Institute of Chemical Physics University of Science and Technology of China
