Theoretical Studies For Several Typical Reactions By Using The Quasiclassical Trajectory

In molecular dynamics fields, the dynamical stereochemistry has recently develpoed oneindependent branch. With the development of theory and experiment, great achievement havebeen made in the chemical dynamics that has gotten into a new stage—the state-to-statechemical dynamics. Focusing on dynamical stereochmistry, we have studiedCa+CH₃I? CaI+CH₃, Ca+CH₂Cl₂? CaCl+CH₂Cl reactions system by using quasi-classicaltrajectory calculation based on a constructed extended-LEPS potential energy surface at thefirst.The outline of the molecular reaction dynamics and stereodynamics of the reactionsystems are given in introduction section. The related theories of QCT, vector correlationtheory are introduced in chapter one.In chapter two, the knowledges of potential energy surface (PES) have been introduced.The Ca+CH₃I? CaI+CH₃ reaction system has been studied by using quasi-classical trajectorymethod on the extended Lond-Eyring-Polanyi-Sato (LEPS) potential energy surface. Atcollision energy E_col=2.58kcal/mol, the calculated results show that the CaI vibrationalpopulation peaks are located at v=2. The calculated cross-section decreases slowly with thecollision energy increasing. The angle product distributions tend to backward scattering. Thecalculated 2(J'-K)> values deviate slightly from -0.5 and decrease with increasing collisionenergies. The QCT results are in reasonable agreement with experimental data. Moreover, thedynamics on the reaction has been discussed.And in chapter three the dynamics reaction of the Ca+ CH₂Cl₂ has been studied by thesam way at the first. The calculated results show that the product CaCl vibrational populationpeaks are located atν=0 at collision energy E_col=2.302kcal/mol. This product statedistribution agrees well with experiment data. The cross-section decreases rapidly in thebeginning and slowly in the end with the collision energy increasing. We have obtained2(J'K)> values deviate slightly from -0.5 and changed interesting with collision energies inround 1.500kcal/mol-20.718kcal/mol.In chapter four the dynamics reaction of the Ca+ CD₃I has been investigated by the samway at the first. We have discussed isotope effect for the reaction of Ca+CH₃I→CaI+CH₃.The calculated results show that the CaI vibrational population peaks moved to low value.The calculated cross-section changed slightness duo to isotope effect. The angle product distributions tend to backward scattering also and isotope effect is not observably. Thecalculated 2(J'x)>values decrease slightly because of decreasing for quality factor.