The Ch <sub> 2 </ Sub> Sh Isomerization And Halogen Atoms X-(x = F, Cl) Reaction Of The Electron Density Topological Analysis Of The Study

The purpose of this paper is to study the geometry configurations, bonding nature by Quantum Chemistry and electronic density topological analysis methods. The rules of breakage and formation of chemical bond in the reaction were discussed in order to help the further research in this field. In this thesis, the breakage and formation of chemical bond in the isomerization reaction of CH2SH and CH3S were discussed. And the microcosmic reaction mechanisms of the CH2SH radical and X(X=F, Cl) atom were also discussed.Gas phase sulfur compounds has significant impact on the atmosphere and the biosphere: the acid rain, visibility reduction and climate modification. So the physical and chemical properties of sulfur compounds are cared by many scientists. CH2SH and CH3S are the key intermediates in the process of the sulfur compounds. There are two aspects about the research of CH2SH and CH3S, the property of single species and the reaction. In this paper, we discussed the isomerization reaction of CH2SH and CH3S and the microcosmic reaction mechanisms of the CH2SH radical and X(X=F, Cl) atom with B3LYP MP2 method, 6-31lG(d,p) basis.In the first part of this paper, previous studies on the sulfur compounds were investigated. There were some studies on CH2SH and CH3S in recent years. At the second part of the work, the wide application of Quantum Chemistry and Quantum Chemical Topology was summarized. Bonding characters and electronic structures are still the main area of quantum chemical research work. Because the electronic density topological analysis method is a new method, there are many studies need to be done by the theory.In chapter three, studies about the isomerization reaction path of CH2SH and CH3S were discussed by electronic density topological analysis methods. The three-member ring structure transition region and structure transition state were found out. The reaction is an exothermic reaction, its structure transition state occurs after energy transition state.In chapter four and five, the reaction mechanisms of CH2SH and X(X=F, Cl) were studied. According to analysis of the transformation of chemical bonds in reaction path, the following conclusions were given: (1) the reaction proceeds throughaddition of the X atom to CH2SH by either F-C or F-S combination to form initial intermediates. (2) The structure transition state exists near every the energy transition state in the two reactions. Structure transition state occurs before energy transition state in endothermic reactions, structure transition state occurs after energy transition state in exothermic reactions. (3) The structure transition regions are broad in unobvious exothermic reactions or unobvious endothermic reactions, are narrow in obvious exothermic reactions or obvious endothermic reactions. (4) The space between structure transition state and energy transition state is small in unobvious exothermic reactions or unobvious endothermic reactions, is small in obvious exothermic reactions or obvious endothermic reactions.The novel conclusions and ideas of this work are listed as follows:1. The isomerization reaction path of CH2SH and CH3S were discussed by electronic density topological analysis methods. The three-member ring structure transition region and structure transition state were found out.2. For the reaction of CH2SH and F, three new possible reaction channels different from literature were found, and the structure transition region and structure transition state were found by electronic density topological analysis methods.3. For the first time, the reaction mechanisms of CH2SH and Cl are discussed.4. The structure transition regions are broad in unobvious exothermic reactions or unobvious endothermic reactions, are narrow in obvious exothermic reactions or obvious endothermic reactions.5. The space between structure transition state and energy transition state is small in unobvious exothermic reactions or unobvious endothermic reactions, is small in obvious exothermic reactions or obvious endotherm...