Theoretical study on amination reaction between 4-amino-1,2,4-triazole and trinitrobenzene

Amination reaction between 4-amino-1,2,4-triazole and trinitrobenzene was theoretically studied. The molecular structures were optimized at the level of HF/6-31G*. Mulliken atomic charges with hydrogen were summed into heavy atoms, the more positive charge of carbon atom help the vicarious nucleophilic substitution (VNS) reaction. The larger margins of energy between amination reagent and reactant make VNS reaction difficult. The optimized conformations of the complex and transition states of amination reaction were also gained. The reaction mechanism of hydrogen transferring and removing was proved. The reduced values of complex-compounds' energy and the margins of energy of front-line orbit were related to the potential energies of the transition states. The more the reduced energy for the complex and the less the margin of the front-line orbit energies for the amination reaction, then the lower the energy barrier of the complex, the VNS reaction will run easily.