Ethylene, the simplest model of a carbon-carbon double bond system, is pivotal in numerous chemical and biological processes. By employing intense infrared laser pump-probe techniques alongside coincidence measurement...Ethylene, the simplest model of a carbon-carbon double bond system, is pivotal in numerous chemical and biological processes. By employing intense infrared laser pump-probe techniques alongside coincidence measurements, we investigate the ultrafast non-adiabatic dynamics involved in the breakage of carbon-carbon double bonds and hydrogen elimination in dissociation of ethylene. Our study entails analyzing the dynamic kinetic energy release spectra to assess three bond-breaking scenarios, movements of nuclei, and structural changes around the carbon atoms. This allows us to evaluate the relaxation dynamics and characteristics of various dissociative states. Notably, we observe a significant rise in the yield of fragments resulting from C–H bond breakage with the delay time extended, suggesting non-adiabatic coupling through conical intersections from C–C bond breakage as a probable cause.展开更多
Taking an image of their structure and a movie of their dynamics of small quantum systems have always been a dream of physicists and chemists. Laser-induced Coulomb explosion imaging(CEI) provides a great opportunity ...Taking an image of their structure and a movie of their dynamics of small quantum systems have always been a dream of physicists and chemists. Laser-induced Coulomb explosion imaging(CEI) provides a great opportunity to make this dream a reality for small molecules or their aggregation — clusters. The method is unique for identifying the atomic locations with angstrom spatial resolution and capturing the structural evolution with a femtosecond time scale, in particular for imaging transient state products. This review summarizes the determination of three-dimensional equilibrium geometry of molecules and molecular cluster system through the reconstruction from the fragments momenta, and also shows that the dissociation dynamics on the complex potential energy surface can be tracked in real-time with the ultrafast CEI(UCEI).Furthermore, the detailed measurement and analysis procedures of the CEI, theoretical methods, exemplary results, and future perspectives of the technique are described.展开更多
Imaging the charge distributions and structures of molecules and clusters will promote the understanding of the dynamics of the quantum system.Here,we report a method by using an Ar atom as a tip to probe the charge d...Imaging the charge distributions and structures of molecules and clusters will promote the understanding of the dynamics of the quantum system.Here,we report a method by using an Ar atom as a tip to probe the charge distributions of benzene(Bz)cations in gas phase.Remarkably,the measured charge distributions of Bz^(+)(δ_(H)=0.204,δ_(C)=-0.037)and Bz^(2+)(δ_(H)=0.248,δ_(C)=0.0853)agree well with the calculated Mulliken distributions,and the structures of Bz2 is reconstructed by using the measured charge distributions.The structures of two Bz2isomers(T-shaped and PD isomers)can be resolved from the measured inter-molecular potential V(R)between two Bz ions,and the structures of Bz dimer agree well with the theoretical predictions.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 12134005, 92261201, and 12274179)。
文摘Ethylene, the simplest model of a carbon-carbon double bond system, is pivotal in numerous chemical and biological processes. By employing intense infrared laser pump-probe techniques alongside coincidence measurements, we investigate the ultrafast non-adiabatic dynamics involved in the breakage of carbon-carbon double bonds and hydrogen elimination in dissociation of ethylene. Our study entails analyzing the dynamic kinetic energy release spectra to assess three bond-breaking scenarios, movements of nuclei, and structural changes around the carbon atoms. This allows us to evaluate the relaxation dynamics and characteristics of various dissociative states. Notably, we observe a significant rise in the yield of fragments resulting from C–H bond breakage with the delay time extended, suggesting non-adiabatic coupling through conical intersections from C–C bond breakage as a probable cause.
基金Project partially supported by the National Key Research and Development Program of China (Grant Nos. 2019YFA0307700)the National Natural Science Foundation of China (Grant Nos. 12004133, 12074143, 12134005, and 11904210)China Postdoctoral Science Foundation (Grant No. 2021M691220)。
文摘Taking an image of their structure and a movie of their dynamics of small quantum systems have always been a dream of physicists and chemists. Laser-induced Coulomb explosion imaging(CEI) provides a great opportunity to make this dream a reality for small molecules or their aggregation — clusters. The method is unique for identifying the atomic locations with angstrom spatial resolution and capturing the structural evolution with a femtosecond time scale, in particular for imaging transient state products. This review summarizes the determination of three-dimensional equilibrium geometry of molecules and molecular cluster system through the reconstruction from the fragments momenta, and also shows that the dissociation dynamics on the complex potential energy surface can be tracked in real-time with the ultrafast CEI(UCEI).Furthermore, the detailed measurement and analysis procedures of the CEI, theoretical methods, exemplary results, and future perspectives of the technique are described.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFA0307700)the National Natural Science Foundation of China(Grant Nos.12074143,11974272,11774281,and 12134005)the Science Challenge Project(Grant No.TZ2018005)。
文摘Imaging the charge distributions and structures of molecules and clusters will promote the understanding of the dynamics of the quantum system.Here,we report a method by using an Ar atom as a tip to probe the charge distributions of benzene(Bz)cations in gas phase.Remarkably,the measured charge distributions of Bz^(+)(δ_(H)=0.204,δ_(C)=-0.037)and Bz^(2+)(δ_(H)=0.248,δ_(C)=0.0853)agree well with the calculated Mulliken distributions,and the structures of Bz2 is reconstructed by using the measured charge distributions.The structures of two Bz2isomers(T-shaped and PD isomers)can be resolved from the measured inter-molecular potential V(R)between two Bz ions,and the structures of Bz dimer agree well with the theoretical predictions.
