Several Chemical Reaction Mechanism, Quantum Chemical Calculation

In the present paper, quantum mechanics method was employed to investigate reaction mechnisms of several organic chemistry reactions, Quantum chemistry Density Functional Theory (DFT) on the level of B3LYP/6-311 + + G (d, p) calculations was used to study all the reaction mechanism by Gaussian 03 proceeding; At the same time tried to preparate ethylenediamine ring-doped carbon materials by nitrilotriacetic acid and yieran. The main contents of the paper are list below:The inter-molecular and intra-molecular dehydration reaction mechanism of Nitrilotriacetic Acid (NTA).Quantum chemistry Density Functional Theory (DFT) is used to optimize the reactants, the transition state and the product, to analyze frequency, the corresponding stable configuration is got by optimizing; Frequency analysis of the transition state of the two dehydration reaction results show that there was only one imaginary frequency in each dehydration, the intra-molecular dehydration transition state for the imaginary frequency is -334.318, the intermolecular dehydration transition state for the imaginary frequency is -257.99. And the two transition states were confirmed by intrinsic reaction coordinate respectively, from the beginning of the transition state, scan in both reaction directions, get the trend picture about energy changes on the reaction path, the transition state, the reactants, and the product were connected very well, which illuminate that in the dehydration process of NTA, transition state was the real transition state in the reaction system of energy changes, and its relative energy and structure closed to the product. In order to illuminate the major change between the atoms of reaction process in IRC more directly, we protracted the change curve of the distance between major atoms along the IRC, from the chart we can clearly see that the occurrence of major changing the distance between the atoms changes along the reaction coordinate. We had analyzed atomic charge of some taking part in reaction by Mulliken charge, and got the each atomic charge changes in reaction process. We had got that intra-molecular dehydration reaction was easier to occur than intermolecular dehydration reaction by analyzing the energy and reaction rate constant of reaction. The activation energy and reaction rate constant of intra-molecular dehydration reaction were 160.2060kJ/mol, k (298K) = 5.825×10^-16s^-1 respectively, and the activation energy and reaction rate constant of intermolecular dehydration reaction were 177.825kJ/mol,k(298K)=7.036×10^-16s^-1. which is consistent with the result of TG-DTA.The reaction mechanism of formic acid of Carbon monoxide and methanol.Carbon monoxide and methanol to form methyl ester formic acid, methyl formate to generate a aroylamino Ammonolysis, Its reaction is CO+CH₂OHâ†'CHOOCH₂, CHOOCH₂+NH₃â†'CHONH₂+ CH₂OH, in which methanol can be recycled, In this paper, Density Functional Theory (DFT) quantum chemical reaction process was used to study the theoretical mechanism in detail. The stability of the corresponding configuration was got by analysing the reactant, transition state, product optimization, frequency analysis, Frequency response analysis showed that there are two steps and only one imaginary frequency, the imaginary frequency for methanol carbonylation is -1551.25, the imaginary frequency for methyl Ammonolysis is -1022.7679. And through the vibration analysis and intrinsic reaction coordinate the two transition states were confirmed by the transition state is correct, respectively. Starting from ransition state, moving in both directions after the scan, the reaction path on the energy change trends was got, and transition state and reactant and product of the formation connect well, fully explaining transition-state energy of the reaction system is the real transition state changes in the carbonylation of methanol and ammonia solution in the reaction process, and its energy and structure are close to the product. In the processing of IRC, in order to more directly explain the major change process between the atoms, we got the changing curve of the distance between atoms along the main curve of IRC, from the chart we can clearly see that the occurrence of major changing the distance between the atoms changes along the reaction coordinate for the methanol carbonylation process, the hydrogen atoms of methanol transfer to carbon monoxide; From the figure we can clearly see that the main changes occurred in the distance between the atoms along the reaction coordinate for the methanol carbonylation process, the hydrogen atoms of methanol transfer to carbon monoxide; Ammonolysis ammonia process is a from hydrogen atoms, while the methyl ester bond, the formation of carbonyl and imine to be a key aroylamino aroylamino. Mulliken charge at the same time was taken to analysis several important atomic atomic charge analysis, the atom charge changes in the reaction process ws realized. The positive response activation energy in each step was got by calculating.