The structure, binding mechanism and properties of hollow layered and sandwiched TATB@C18 and TNT@C18 composites: a DFT study

In this work, in order to develop new advanced energetic composites with better safety performance, composites with different proportions and sizes including TATB@C18, TNT@C18, 2TATB@C18, 2TNT@C18, TATB@2C18 and TNT@2C18 were designed and constructed by a all carbon compound named cyclo[18]carbon (C18) and two famous and widely used energetic compounds 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and 2,4,6-trinitrotoluene (TNT). Then, the molecular and electronic structures, binding mechanism and properties of them were investigated theoretically. The results showed that both TATB and TNT can form stable hollow layered and sandwiched composites with C18 through the C...O, C...N and C...C interactions, while the binding strength of former composites is much better than that of later one. When compared to TATB and TNT, the safety performance of composites was much better. On the one hand, their impact sensitivity is lower to that of TATB or TNT slightly. On the other hand, the energy gap of TATB and TNT can be significantly reduced about 30% by C18. The safety performance could be flexibly adjusted by changing the proportion of TATB, TNT or C18. In addition, the short recovery time and the big difference in the UV-Vis spectrum between sole TATB or TNT and composites may indicate the high potential to use C18 as a new sensor for the explosive trace detection.