Study on the electronic structure and molecular response mechanism of triazole derivatives under electric field regulation.

Context: This article selects three excellent energetic materials: [4,4'-Bi-4H-1,2,4-triazole]-3,3'-diamine (1); 5H-1,2,4-triazolo [4,3-b] [1,2,4] triazole-3,6-diamine (2); and 4,4'-(1E)-1,2-diazenediylbis [4H-1,2,4-triazol-3-amine] (3). Use density functional theory to study molecular structure, surface electrostatic potential, molecular frontier orbitals, and density of states. The X-axis EEF is enhanced by 1 and 3, but weakened by 2; the Y-axis EEF has an enhancing effect on 2, but weakens 1 and 3. Under the X/Z-axis EEF, the polar surface area expands and the Y-axis slightly decreases; 2 forms a uniform negative potential region in the first half of the Z-axis strong electric field; the polar surface area of X-axis increases, while the Y/Z-axis significantly decreases. The EEF reconstructs the HOMO/LUMO spatial distribution and reduces the energy gap, significantly enhancing reaction activity. In summary, the EEF can precisely regulate the bond stability, surface charge distribution, and electronic excitation characteristics of energetic materials through the synergistic effect of direction and intensity, providing a theoretical basis for the safe storage, transportation, and active design of energetic materials.

Methods: Using density functional theory, the B3LYP/6-311 + G(d,p) method was employed for structural optimization. After optimizing convergence, ensure that there are no imaginary frequencies to obtain a stable structure. Wave function analysis was performed using Multiwfn 3.8 and VMD 1.9.3. The EEF strength ranged from 0 to 0.02 a.u., with a growth gradient of 0.005 a.u.