Synthesis of energetic coordination compounds based on pyrazole and 4-chloropyrazole via co-melting crystallization method

Abstract

This research utilized a recently developed co-melting crystallization method to synthesize four distinct energetic coordination compounds (ECCs). The method involves the direct heating of organic ligands with inorganic salts, leading to the formation of the desired ECCs upon cooling and subsequent crystallization. This approach effectively bypasses various challenges associated with the conventional solvent-based ECC preparation process. In this study, the organic ligands employed were pyrazole and 4-chloropyrazole, while the inorganic salts included copper nitrate and copper perchlorate. A rigorous pre-experiment was meticulously designed to validate the feasibility of this method, followed by control experiments to underscore its advantages. Subsequently, comprehensive characterizations were conducted on the four ECCs, with a primary emphasis on their crystal structures and energetic properties. Notably, ECCs-3 and ECCs-4, among the synthesized ECCs, exhibit significant potential for applications in pyrotechnic materials and ignition agents. This work extends the practical applicability of the co-melting crystallization method we have developed, providing further substantiation of its advantages and potential.