K₂MODNP: A Lead-Free Initiator with Excellent Thermal Stability and Promising Energetic Performance

Researchers in the field of high-energy density materials are actively exploring toxic metal-free alternatives for traditional primary explosive lead azide due to its well-known environmental and health threats. In this work, dianionic N,N'-methylene-bridged 4-hydroxy-3,5-dinitropyrazole was paired with potassium cations to synthesize dipotassium 1,1'-methylenebis(3,5-dinitro-1H-pyrazol-4-olate) (K₂MODNP), a primary explosive with a positive oxygen balance with respect to CO (3.67%), excellent thermal stability (T_d = 282 °C), and performance exceeding that of lead azide (LA). Notably, this compound exhibited the highest thermal stability among most reported nitropyrazole-based primary explosives to date. The activation energy was determined using Kissinger's and Ozawa's methods, supporting its promising potential as a lead-free primary explosive.