Lewis Acid B (C₆F₅)₃ Catalyzes The N-alkylation Of Amines And The Catalytic Degradation Of P-nitro By Zirconium UiO-66 Study On The Reaction Mechanism Of Phenyl Phosphate

Recently,quantum computational methods have been widely applied to various fields of chemical research,and the methods have been a powerful tool for studying the mechanisms of complicated organic reactions especially.In this paper,density functional theory is used to systematically study the mechanism of Lewis acid B(C6F5)3-catalyzed N-alkylation of amine and the Zr-MOF UiO-66-catalyzed degradation of p-nitrophenyl phosphate(pNPP),The main contents are as follows:The first chapter introduces the mechanism of reductive reaction of organic compounds catalyzed by Lewis acid B(C6F5)3,and the mechanism of organophosphate degradation catalyzed by metal-organic frameworks.The second chapter presents the basic theories and methods of quantum chemistry.The third chapter explores the mechanism of Lewis acid B(C6F5)3-catalyzed N-alkylation of amine.The total reaction is divided into two sections:(1)acid-amine condensation.The condensation pathway via the assistance of acid is favorable,and its rate-determining step barrier is 22.4 kcal/mol.(2)the reduction of the amide.The favorable pathway is B(C6F5)3-catalyzed hydrosilation reaction of amide,with the rate-determining step barrier of 24.7 kcal/mol.The fourth chapter explores the mechanism of pNPP degradation by Zr-MOF UiO-66.In our theoretical calculation,the defective structure of UiO-66 with removal of one formic acid ligand was chosen as the theoretical model,with the metal active sites Zr-O-Zr,and the molecular formula Zr6(?3-O)5(?3-OH)3(HCOOH)11.In the catalytic degradation of p-nitrophenyl phosphate(pNPP)by Zr6-based MOF UiO-66,all possible reaction mechanisms under neutral and alkaline conditions were discussed to obtain the optimal reaction path.In neutral conditions,the most feasible degradation processes are as follows:(1)two water molecules coordinate to two adjacent Zr atoms of defected UiO-66 respectively;(2)the proton of one water molecule transfers to ?3-O atom,forming the complex IM,A,with thestructure of HO-Zr-(?3-OH)-Zr-OH2;(3)two oxygen atoms of pNPP form hydrogen bonds with the water ligand and hydroxyl ligand of complex IM-A,generatings complex IM5;(4)nucleophilic attack at the central phosphorus atom of pNPP by OH group,accompanied by the departure of p-nitrophenol anion.During the overall process,the fourth step is rate-determining step,with a free energy barrier of 12.0 kcal/mol.Under alkaline conditions,the most favorable degradation processes are as follows:(1)the bidentate coordination of two oxygen atoms of pNPP to two Zr atoms adjacent of defected UiO-66 forms the complex IM25;(2)an OH-from the solution attacks central phosphorus atom of pNPP in a concerted mechanism,with departure of p-nitrophenol anion.During the above process,the second step is the rate-determining step,with the energy barrier of which is 6.8 kcal/mol.