Balancing the Energy and Sensitivity of Primary Explosives: Using Isomers to Prepare Energetic Coordination Compounds

The performance of energetic coordination compounds (ECCs) is influenced by their components and structure. Modifying the chemical structure of the ligands can balance the detonation performance and sensitivity. This study introduced Cu(3-PZCA)2(ClO4)2 (ECCs-1) and Cu(2-IZCA)2(ClO4)2 (ECCs-2), using 3-PZCA and 2-IZCA as ligands. ECCs-2, with a higher symmetry and fewer nitrogen chains, showed the highest thermal decomposition temperature (225 °C). Both ECCs displayed high mechanical sensitivity, with ECCs-2 being slightly less sensitive (IS = 3 J, FS = 8 N). They shared similar detonation properties and ignition capabilities, with ECCs-1 having the highest detonation velocity (7.1 km·s-1) and pressure (23.5 GPa). Initiation tests confirmed their excellent performance and similar DDT. The theoretical decomposition mechanism suggests a free radical reaction, explaining their consistent mechanical sensitivity, ignition, and initiation capabilities. A "SP–DM–DSC–MS–DA" structure–property relationship was established, providing a theoretical foundation for studying Cu(ClO4)2-ECCs and their isomers.