噁二唑硝胺化合物在水中稳定性及其水解机制

To explore the hydrolysis behavior and internal rule of oxadiazole nitramide compounds, the natural bond orbit(NBO) charge distribution and lowest unoccupied molecular orbital (LUMO) orbital distribution of unstable oxadiazole nitramide compounds were analyzed by theoretical calculation. LUMO orbital coverage was found in the carbon center connected with the nitramide group, which was the possible reaction site and the NBO charge at this site was the highest in the molecule (usually around 0.7 a.u), which was the main factor leading to the occurrence of hydrolysis reaction. Based on this consequence, the hydrolysis reactions of N, N'-([3, 3'-bi(1, 2, 4-oxadiazole)]-5, 5'-diyl)dinitramide and N, N'-([2, 2'-bi(1, 3, 4-oxadiazole)]-5, 5'-diyl)dinitramide (ICM-101) compounds were successfully predicted. The hydrolysis products [3, 3'-bi(1, 2, 4-oxadiazole)]-5, 5'(4H, 4'H)-dione and [2, 2'-bi(1, 3, 4-oxadiazole)]-5, 5'(4H, 4'H)-dione were obtained by hydrolysis experiments in boiling water. Then the corresponding structures were characterized, the site of hydrolysis reaction was identified, and the mechanism of hydrolysis reaction was elucidated. Using the method of structural equivalence, the order of the hydrolysis activity of azole nitramide compounds was put forward as follows: furazan < 3-substituted-1, 2, 4-oxadiazole < 1, 2, 4-triazole < 1, 3, 4-oxadiazole < 5-substituted-1, 2, 4-oxadiazole.