Quantum Calculation Of Several Common Oxygen-Containing Molecule Activities In The Atmosphere By Chemical Analysis Of Chlorocarbene Radical Anions

Nowadays,the"green"and"environmental protection"themes of international development aim to make clean energy sustainable as well as require that the whole development and useful process is environmentally friendly.Hence,preserving energy and protecting the environment are essential to developing the chemical industry.Gas-phase negative ion reactions play a key role in chemical products and have a crucial impact on effective synthesis mechanisms;they have become a research hotspot to explore the physical and chemical properties of various compounds by using oxygen-containing molecules and gas-phase negative anions.In this work,the gas-phase negative anions CHCl^·-and MO^-（M=Be,B,Al）are used to analyze the reaction mechanism of gas-phase negative anions by using density functional theory.Exploring and revealing the role of negative anions in atmospheric intermolecular transformation is expected to provide basic theoretical guidance for atmospheric green and environmental protection research based on gas phase negative anions.There are five chapters in the paper:In chapter 1,firstly,describes the development history of quantum chemistry and the major achievements at each step.Secondly,it is explored that gas-phase negative anions research in the atmosphere,as well as advantages and applications;and it also provides an overview of the paper’s unique points from two angles:basis of subject selection and research content.In chapter 2,it is summarized that the basic theory of quantum chemistry mainly introduces the Schr?dinger equation,density functional theory,basis set,reaction potential energy surface,S_N2 reaction mechanism,and quantum chemical calculation software.In chapter 3,compared with the reaction mechanism of CHCl^·-with formaldehyde and water,the BHand HLYP method with the aug-cc-p VDZ basis set is used from density functional theory.The results show that:（1）The H-abstraction reaction mechanism is the main channel in the CHCl^·-+H₂O reaction.（2）By comparing the H-abstraction and O-transfer mechanisms,it was found that the intramolecular S_N2 reaction mechanism was the preferred channel for CHCl^·-+HCHO reaction.（3）Compared with the main reaction channel of CHCl^·-+HCHO,the reaction between CHCl^·-+H₂O is a minor reaction.（4）During the atmospheric reaction,the reaction between HCHO and CHCl^·-does not produce an obvious accelerated reaction due to the presence of H₂O molecules.In chapter 4,in order to explore the mechanism of CHCl^·-with O₃ and S₂O at the molecular level,it is established that S₂O+CHCl^·-and O₃+CHCl^·-reaction mechanisms by the DFT-BHand HLYP method.Chapter 4 shows the following four conclusions:（1）the favorable path in the CHCl^·-+O₃ reaction is the O transfer reaction mechanism determined by Path 6.（2）Compared with the H-abstraction and Cl-transfer mechanisms,the CHCl^·-+S₂O reaction prefers the intramolecular S_N2reaction mechanism.（3）The CHCl^·-+S₂O reaction is more favorable thermodynamically than the CHCl^·-+O₃ reaction,and the CHCl^·-+O₃ reaction is more favorable dynamically and more efficient.（4）According to the kinetic and thermodynamic analyses,the CHCl^·-negative anions are very effective in the degradation of O₃ and S₂O.In chapter 5,using DFT-BHand HLYP method the three different gas-phase anions MO^-（M=Be,B,and Al）drive the reaction of the CCl₃H molecule to abstract H atom.The results show that:（1）The most favorable reaction path determined in the gas phase negative ion BO^-reaction is the path activated by the B atom,while in the Be O^-and Al O^-reactions,it is O atom.（2）Compared with BO^-and Al O^-,the energy barrier of C-H bond activation in CCl₃H by Be O^-is relatively lower.（3）After calculating the rate constant between 298 K and 1000 K for the most favorable HAT reaction by the transition state theory,it is found that the lower the temperature,the faster the BO^-chemical reaction rate.