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Prof. Keli Han’s Laboratory (Team 1101): Molecular Beam Reaction Dynamics
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| Introduction : |
The group is led by Prof. Dr. Keli HAN, consisting of 2 staff scientists Mr. Guangjun WANG and Mr. Julong SUN, 4 postdoctors (Dr Tingxian Xie, Dr Qingtian Meng, Dr Guanghui Yang, Dr Meishan Wang) and 12 graduate students. The group is engaged in theoretical and experimental studies of Molecular Reaction Dynamics. On the experimental side, recently we have focused our studies on the gas phase photodissociation dynamics of small organic molecules containing halogen atoms and NO molecules. First of all, the photofragment translational spectroscopy (PTS) technique has been employed to determine the b parameter and the translational energy distribution of fragments on the universal crossed molecular beams machine. A typical example is that the photodissociation dynamics of m-, o- and p-chlorotoluene at 266 nm was studied, in which the hydrogen transfer in o-chlorotoluene has been confirmed. The second approach to study photodissiciation dynamics is the pump-probe technique, in which the first laser is employed to photolyze the parent molecule and then the second laser is used to probe the fragment. In this case, the vibrational distribution, the rotational distribution, and the rotational alignment can be determined. A typical example is the photodissociation dynamics of CH3ONO, in which we not only measure the NO rotational alignment but also determine the CH3O rotational alignment. In addition, femtosecond time-resolved vibrational relaxation dynamics of dye molecule in solution as a function of temperature has been performed.
On the theoretical studies, we have focused our studies on quantum reaction dynamics and potential energy surface calculations including nonadiabatic reaction dynamics and spin-orbital coupling. Moreover, at first, the trajectory and time-dependent wavepacket have been employed to study stereodynamics of bimolecular reaction. Second, we have developed a method to calculate femtosecond-resolved photoelectron spectrum and photodissociation in strong laser field. Third, we use density matrix theory to derive the formulae to determine the orientation and alignment of symmetric top molecule by means of (n+1) LIF. Fourth, we have used time-dependent wavepacket method including SVRT model to study reaction dynamics and photodisociation. We have close cooperation with Professor John Zhang at Department of Chemistry of New YorkUniversity in this project.
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| Research Interests : |
Experimental and Theoretical Chemistry including: Dynamical Stereochemistry, Crossed-beam Experiments, Photodissociation Dynamics, Ab initio calculation, Classical Trajectory calculation, Time-dependent wavepacket calculation, Measurement and calculation of rate constants related to combustion, environmental chemistry, and material chemistry.
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| Research Projects : |
1. Photodissociation dynamics (Outstanding youth foundation from NSFC Project 1999-2002, RMB0.8 million)
2. Stereodynamics of Chemical Reaction (The Director Foundation of NSFC Project 1999-2002, RMB2.1 million)
3. Selective Control of Chemical Reaction and Related Phenomena (National Key Basic Research Project 2000-2005, RMB3.5 million)
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