Atmospheric Sulfur Reaction Mechanism Of The Transient Species And The Electron Density Topological Study

The purpose of this paper is to study the geometry configurations and bonding nature by quantum chemistry and topological analysis of electronic density. 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 microcosmic reaction mechanisms of CH₃SH and XO(Cl,Br) radical were discussed. And the microcosmic reaction mechanisms of the CH₃S radical with Ox(X=:l ,2,3) and the isomerizations of CH₃SO were also discussed.With development of the modern industrial technology, the deterioration of the ecological environment has caused more and more concerns, the air pollution question is the most important one these years, and the destroy which caused to the ecosystem by the acid rain has already been one of the ten important problems threatened the world environments. The sulfur compounds help to form the acid rain, so they are studied by more and more scientists. CH₃SH accounts for around 10% of the global flux of sulfur compounds in the atmosphere, and it was found as one of the interplanetary species in 1979.CH₃S radical is a key intermediate in the process of sulfur compounds oxidation in the atmosphere. SO₂, which is one of the productions of these reactions, is an important resource forming the acid rain. In this paper, we discussed the microcosmic reaction mechanisms of CH₃SH and CH₃S with B3LYP/6-311G(d, p). The isomerizations of CH₃SO have also been studied in B3LYP,CCSD(T),QCISD,MP2 methods and 6-31 lG(d,p) basis set.In the first part of this paper, we summarize the studies on CH₃SH and CH₃S with simple radicals in recent years.In the second part, 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 topological analysis of electronic density is a new way, there are many studies need to be done by the theory.In chapter three and four, the reaction mechanisms of CH₃SH and XO(Cl,Br) were studied by topological analysis of electronic density respectively. Several reaction channels of the two reactions were gained through the quantum chemistry computation. The rules of chemical bonds in these reactions are discussed with topological analysis of electronic density.In chapter five, the reaction mechanisms of CH₃SH and O_X(X= 1,2,3) were studied. The seven reaction channels that the acid rain would come into being were found in the...