Ab Initio Study Of Ozone Depletion By Bromine

Ozone depletion in the polar stratosphere has become one of the global environmental questions. Ozone can absorb ultraviolet radiation strongly, which can make the organism exempt from the hurt of ultraviolet radiation. To clarify the mechanism of stratospheric ozone depletion, scientists have strengthened the research of stratospheric ozone depletion chemistry. Now the scientists have already confirmed that some chemical reactions taking place in the stratosphere are the main reason for ozone depletion, and have proposed some catalytic cycles which destroy the ozone badly in the stratosphere, and have further confirmed Chloro Fluorocarbons and Methyl Bromide are the most important artificial chemical materials which destroy the ozone badly in stratosphere.There are many chemical substances destroying ozone in the atmosphere, such as free radical and small active molecule. These deoxidization small molecule and active free radical reacted with oxidation ozone. These years, it's the main content of atmosphere chemistry to study how they reacted. These results will provide theory evidence and experiment direction for ozone protect. Chlorine and bromine contained compounds are deemed to be the main species lead to ozone depletion. Bromine compounds are easy to product bromine contained free radical such as Br and BrO, which have more efficiency of ozone depletion. Therefore, there is important meaning to study the process of ozone depletion by Br.In this thesis we use quantum chemistry method studied the reaction of Br+O3. We optimized the transition state in reaction coordinate of the reaction, and carry on the IRC (intrinsic reaction coordinate) calculation to confirm the existence of this transition state. We also calculated two catalytic cycles of ozone destroyed by Br at different levels. At first present mainly the calculated geometrical structure, enery, vibrational frequency, dipole moment and so on and analyzed from these respects. On the basis of optimized structures, the calculated reactional energy, enthalpy of formation, and relative Gibbs free energy of the reactions in the catalytic cycles at different methods are consisted with each other. And the results show that all reactions carry on toward the direction of the energy...