To further test whether polynitriprismanes are capable of being potential high energy density materials (HEDMs),extensive theoretical calculations were carried out to investigate on a series of polynitrotriprismanes (PNNPs):C6H6-n(NO2)n (n=1-6).Heats of formation (HOFs),strain energies (SE),and disproportionation energy (DE) were obtained using B3LYP/6-311+G(2df,2p)//B3LYP/6-31G method by designing different isodesmic reactions,respectively.Detonation properties of PNNPs were obtained by the well-known KAMLET-JACOBS equations,using the predicted densities (ρ) obtained by Monte Carlo method and HOFs.It is found that they increase as the number of nitro groups n varies from 1 to 6,and PNNPs with n 4 have excellent detonation properties.The relative stability and the pyrolysis mechanism of PNNPs were evaluated by the calculated bond dissociation energy (BDE).The comparison of BDE suggests that rupturing the C-C bond is the trigger for thermolysis of PNNPs.The computed BDE for cleavage of C-C bond (88.5 kJ/mol) further demonstrates that only the hexa-nitrotriprismane can be considered to be the target of HEDMs.
