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Synthesis, Structure, Thermal Decomposition Mechanism Of Triadimefon And Its Salts, Non-isothermal Decomposition Reaction Kinetics And Theoretical Research

Posted on:2005-01-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:H X MaFull Text:PDF
GTID:1111360125452008Subject:Chemical Engineering
Abstract/Summary:PDF Full Text Request
4-Amino-1,2,4-triazol-5-one (ATO) was synthesized and its single crystal was cultured. The structure was measured by a four-circle X-ray diffractometer. Its thermal behavior was studied by DSC in a sealed cell of stainless steel with static air and an unsealed cell of ceramic with nitrogen atmosphere. The kinetic parameters and mechanism function were determined by non-isothermal method. Through the techniques of T-Jump in normal pressure, the decomposition products of ATO were determined to be composed of HCN, NH3, CO, HNCO, NO and CO2, while the second endothermic peak of ATO in the unsealed cell of ceramic is a volatile peak. The theoretical calculation was carried out with Gaussian 03 W to get the optimized parameters, the IR frequencies and NMR chemical shifts. The calculated results were in agreement with those of the experimental.To prepare NTO salts in organic solvents, the dissolvable capability of NTO in organic solvents: cyclohexylamine, n-heptane, benzene, toluene, 1,2-dichloroethane, methanol, ethanol, propanol, n-butyl alcohol, nitromethane, acetonitrile, pyridine, ethylenediamine anhydrous, dimethyl sulfoxide, 1,4-dioxane, tetrahydrofuran, ethylene glycol dimethylether, dimethylformamide, triethanolamine, acetone, diethyl ether, and toluene-ethanol was studied. The single crystals of NTO sodium and magnesium salts were obtained and their crystal structures were determined by a four-circle X-ray diffractometer.The dimethylamine salt of NTO (DMANTO)was prepared and single crystals were obtained by recrystallization with a mixed solvent of methanol and dimethyl formamide (v/v=5:l) at room temperature. The.apparent activation energy of the exothermic decomposition reaction was determined by non-isothermal kinetic method. Theexperimental geometry was fully optimized with Gaussian 98W. The calculated bond distances, bond angles, NMR chemical shifts and IR frequencies were compared with the experimental values and the theoretical values were in accord with those of the experimental.The DSC, TG/DTG and FT-IR techniques were used to study the thermal decomposition mechanism of 15 kinds of NTO salts which are Li(NTO)(H2O)2 powder and crystal, Na(NTO) H2O powder and crystal, K(NTO) H2O powder and crystal, Rb(NTO)'H20 powder, Cs(NTO>H20 powder, [Mg(H2O)6](NTO)2'2H2O powder, [Sr(NTO)2(H20)4] 2H2O powder, [Co(H20)6](NTO)2 2H2O powder,[Ni(H2O)6](NTO)2'2H2O powder and crystal, [Cd(NTO)4Cd(H2O)6] 4H2O powder and H[PrCNTO)4(H2O)4] 2H2O powder. For Li(NTO)(H2O)2 powder, there was a little exothermic decomposition peak before the severe exothermic process while there was only one exothermic process in Li(NTO)(H2O)2 crystal. Both Na(NTO) H2O powder and crystal lost the coordinate water by two steps but the mass loss was different. The dehydration of K(NTO) H2O powder was composed to be two steps, and that of K(NTO) H2O crystal was only one step. [Ni(H2O)6](NTO)2 2H2O powder had two peaks within the first endothermic process in DTG curve, while the crystal had one.The Kissinger method, Ozawa method, the differential method and the integral method were carried out to determine the above-mentioned 15 kinds of materials' kinetic parameters, the apparent activation energy (E) and the pre-exponential (A) in the dehydration and exothermic processes. The thermal decomposition mechanism function were got and the value (Tpdo) of the peak temperature (Tp) corresponding to 0, the critical temperature of thermal explosion (Tb), the entropy of activation ( S ), enthalpy of activation ( H) and free energy of activation ( G ) were obtained. The temperature-resistant regularity of these salts was also discussed. The relationship between the enthalpy of activation and Tpdo of NTO alkali metal salts was determined.Two isomers of l,2,4-triazol-5-one (TO) geometries were optimized. Through thecomparison of the optimized geometries, molecular total energies, frontier orbital energy levels and its gap, the stable geometry was obtained which was in agreement with the experimental result. Our...
Keywords/Search Tags:4-amino-1, 2, 4-triazol-5-one (ATO), 3-nitro-1, 4-triazol-5-one (NTO), NTO salts, molecular structure, Thermal decomposition mechanism, Non-isothermal kinetics, Theoretical calculation
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