Theoretical Study On The Reaction Mechanism Of Tautomerization Of 3-Substituted Indazole

Two parts are included in this thesis.In the first part, quantum chemistry calculation was reviewed in general, its researchprinciple, function and its developing process were described briefly. Three researchmethods of quantum chemistry calculation were introduced, such as Austin Model 1, Density functional theory and Ab initio method.In the second part, Molecular structures of indazole and 3-substituted indazoletautomers were calculated employing the electron correlated Becke3LYP functional of thedensity functional theory by implementing 6-311G^** basis set, both in the gaseous andaqueous phases, with full geometry optimization. The solvent effects were calculated usingOnsager and PCM solvate theory model with the dielectric constant of 78.39 to simulatethe water solvent. The total energy, enthalpy, Gibbs free energy and dipole moments havebeen calculated for all the optimized molecular structures. The influence of the different3-substitutent and solvent effect on the geometrical structure, energy, charge and activationenergy were discussed. The reaction mechanism of tautomerization of indazole and3-substituted indazole were also studied and a three-membered cyclic transition state of thetautomer reaction has been obtained.