We presented two new members of molecular perovskite high-energetic materials, (Hpz)[Na(ClO)] (PAP-1) and (Hdabco-O)[K(ClO)] (DAP-O2), in which Hpz (piperazine-1,4-diium) and Hdabco-O (1-hydroxy-1,4-diazabicyclo[2.2.2]octane-1,4-diium) act as A-site fuel cations, respectively. Compared with their Hdabco analogues, (Hdabco)[M(ClO)] (Hdabco = 1,4-diazabicyclo[2.2.2]octane-1,4-diium, M = Na for DAP-1 and K for DAP-2, respectively), PAP-1 and DAP-O2 exhibit optimized oxygen balance by employing two strategies to change the A-site cations, i.e., "trimming the C and H atoms" of Hdabco by using Hpz to form PAP-1 and adding an O atom into Hdabco by using Hdabco-O to form DAP-O2, respectively. As suggested by DFT calculations and the K-J equation, the smaller Hpz cation in PAP-1 gives a significantly-optimized oxygen balance from -22.0% to -3.9% and an increased crystal density from 2.02 to 2.07 g cm, resulting in a better detonation performance for PAP-1. Meanwhile the larger Hdabco-O cation gives a slightly-optimized oxygen balance from -21.3% to -17.1% but a decreased crystal density from 2.04 to 1.98 g cm, leading to a decreased detonation performance from DAP-2 to DAP-O2. This study demonstrated how to rationally choose the A-site cations in a perovskite structure for modulating the properties of molecular perovskite high-energetic materials, providing important clues for designing more advanced energetic materials for practical use.
Chen Shao-Li Shang Yu Chunting He Sun Lin-Ying Ye Zi Ming Weixiong Zhang 陈小明