Theoretical Study For The Reaction Of N12o （x¹Î£⁺） With Co （¹Î£⁺） Catalyzed By IrO_n⁺（n=1,2） And The Oxidization Reaction Of Nh₃Catalyzed By Fe⁺in The Prese

The activation of traditionally inertia bonds （such as N-H bond、N-O bond） isbecoming more attractive for its importance in industry and basic chemistryresearch. They can be high activity and high selectively catalytic rupture iscatalytic chemist long tireless pursuit. However, Transition metal or transitionmetal oxides due to the existence of the d orbital and so make the chemical naturepresents some particularity. For example: in the thermal chemical reactions theyalways appears the phenomenon of spin-forbidden.During the course of reaction,itwould appear the intersystem crossing phenomenon due to the high spin-orbitcoulping and lead to the reaction occurs on the minimum reaction path.Namely, areaction possibly occurs on two or more potential energy surfaces （PESs）.At theregion of intersystem crossing,different electronic states have almost identicalenergy value,Born-Oppenheimer approximation is destroyed due to the spin-orbitcoupling.Intersystem crossing becomes the key factor to determine non-adiabaticreaction rate, reaction system will avoid the high activation barrier and make thenon-adiabatic reaction rate improve obviously compared with the adiabaticreaction rate. However, potential surface is a hypersurface, the crossing of twosurfaces has many points, and it is difficult to search the minimum energycrossing point （MECP）. The value of spin-orbit coupling between different spinpotential surfaces and the probablity of intesystem crossing have the largest valueat this point.For a catalytic cycle reaction,the detailed kinetic information will providetheoretical support for the design of catalyst and to evaluate the performance ofcatalyst. In recent years, Kozuch team has been devoted to the study of thissubject and this problem has been conquered via a lot of mathematical derivation.The energy span model was proposed. All transition states and intermediates wereoptimized and the corresponding Gibbs free energy were obtained to establish theaccurate different spin state potential surfaces.Taking the Gibbs free enegy of thetransition states and intermediates on the minimum energy reaction path intoenergetic span model to obtain the value of degree of turnover frenquency of allthe transition states and intermediates, and it is a method to identifying the turnover frenquency determined transition states and turnover frenquencydetermined intermediate, and also for deciding whether there are more statesdetermine the kinetic information of catalytic cycle. Meanwhile, the contributionof all transition states and intermediate to the kinetic the whole catalytic cycle wascalculated. Finally, the energetic span was confirmed.In this paper, CO, N₂O, NH3, O₂molecules are used as models for theactivation of inert molecules, the geometries of all the reactants, intermediates,transition states and products on the potential energy surfaces （PESs） areaccurately optimized, and strive to establish a more accurate potential energysurface, To locate the crossing seam between the two PESs of different spin states,we have carried out the vertical excitation method for the single-point energycalculations along the IRCs,and the partial optimization method, in these ways,we have obtained the crossing point （CP）. However, the CP point is not theminimum energy crossing point （MECP）. Actually MECP is not a practical point,because different spin state wave function with certain coefficient linear tocombined to get a mixed state in cross region, we can only through themathematical method to get to a point to approximate as MECP. Here, MECPbetween PESs was identified by using the procedures of Harvey et al.To furtherexplore the characteristics of non-adiabatic dynamics, the effective spin-orbitcoupling （SOC） in the MECP region is calculated using the GAMESS programpackage.Taking multi-spin states potentially surfaces non-adiabatic reactionkinetics theoretical calculation as means and turnover frequency （TOF） researchapproach proposed by Kozuch is referenced, The detailed kinetic information ofthe whole catalytic cycle is finally obtained based on this model.The whole thesis consists of four chapters. Chapter1and Chapter2describethe progress and application of quantum chemistry as well as the development andthe present situation of TSR/MSR, and briefly introduce elementary theory andquantum chemistry computation methods. The contents of the two chapters are thebasis and background of our studies and offered us with useful and reliablequantum methods and analysis method.In Chapters3, taking the experiment of K.Bome as research foundation, the reactions of the IrO_n⁺（n=1,2）with N₂O （CO） have been studied carefully usingthe different theoretical methods. The mechanisms of crossing seam between thetwo PESs and the activation of N-O bond have been investigated. To furtherunderstand the "intersystem crossing" mechanism, the spin-orbit coupling matrixelements are discussed in detail. Finally, the kinetic information for these systemswas obtained and thus evaluated the performance of two catalysts.In Chapter4, Based on the experiment foundation of Zhao，W. Buckner andBr nstrup, the reaction mechanism of the N₂O,O₂,NH₃and Fe⁺were theroreticalinvestigated, possible spin-flip processes and the key role of SOC werediscussed.The turnover frenquency of two possible reaction path were calculatedand the minimum energy reaction path was finally confirmed. The detailed kineticinformation was obtained.