Theoretical Studies Of Electronic Donor-Accept Relationship In Small Molecular Reaction Based On Density Functional Theory

The rapid development of quantum chemistry and theoretical methods make it possible to explain profoundly and profoundly the mechanism of organic chemical reaction process and its variation through theoretical calculations.The main content of this dissertation is to study the organic reaction mechanism of transition metal complex and nonmetal lic FLP and the nature of bond formation by using the theoretical calculation method based on quantum chemistry platform.The basic contents are divided into the following aspects:The first chapter briefly introduced the reaction mechanism of the participation of metal and nonmetallic catalysts and the theoretical introduction of the nature of bond formation;The second chapter introduced the theoretical basis and calculation method.The third to the fifth chapter for my master's degree in AHU during the main research work.Among them:In the third chapter,the Diels-Alder reaction of ruthenium-catalyzed electrically mismatched diolefin and dienophile substrate was studied.By using the classical M062X density functional theory and the basis set stratification calculation model system.The mechanism details by comparing the energy requirements of various possible reaction pathways and analyzing the structure and electronic properties of the key intermediates and transition states in the reaction process,we finally deduced the most likely reaction path for this reaction and based on this,The effects of different substituents on the reaction,the effects of substituents,and broaden the scope of this type of reaction substrate.This paper was published in RSCAdv.,2017,7,30618.In the fourth chapter,the reaction mechanism of a series of nonmetallic metal complexes(P-B,P-Al,N-B,etc.)with hydrogen is studied.The mechanism of various reactions is studied using density functional theory(M062X)Details and its inherent regularity.By analyzing and comparing the mechanism of FLP catalytic hydrogenation in different non-metallic centers,we find that the reaction mechanisms of various non-metallic FLP catalysts and hydrogen are similar.There are two different mechanistic histories:one is the a(H2)bonding orbital providing an electron pair to the Lewis acid(LA)orbital while the ?*(H2)antibonding orbital accepts the Lewis base(LB)lone electron,While H2 hydrogenation is completed to complete the hydrogenation.The other is that H2 first combines with LA to form a three-center two-electron complex[H2-LA],and then the H-H ? bond in the complex undergoes proton hydrogen Transfer to LB to complete the hydrogenation.This paper is to be published.In the fifth chapter,three kinds of XeO4,Xe(NH)4,Xe(CH2)4 complexes with Xe complexes were characterized at the M062X/def2tzvp level by means of bond length,NBO charge and bond level,and LOL and AdNDP,Xe(CH2)4,the bonding properties of these three complexes are briefly described.In the above work,the theoretical calculation method was used to study the details of the reaction mechanism and its inherent regularity.The theoretical results were in good agreement with the experimental data to verify the theoretical method in the study of the reaction mechanism.In the feasibility of,but also provides many other experimental methods can not be obtained mechanism of information,such as the key Intermediates,the transition state of the structure and visual image of the mechanism of image.The research results of this thesis are expected to provide theoretical support and guidance for the future design and development of new metal-organic chemical reactions and new catalytic systems.