Structure-Induced Energetic Coordination Compounds as Additives for Laser Initiation Primary Explosives.

Cui, Meng; Yan, Yun-Fan; Qian, Rui-Xuan; Fan, Bo-Wen; Bian, Hong-Yi; Wen, Fei; Xu, Jian-Gang; Zheng, Fa-Kun et al. · Adv Mater · 2025

basic_science · Level V

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Abstract

Laser ignition of primary explosives presents more reliable alternative to traditional electrical initiation methods. However, the commercial initiator lead azide (LA) requires a high-power density laser to detonate, with the minimum laser initiation energy (E<sub>min</sub>) of 2402 mJ. Currently, the laser-ignitable metal complex-based igniters still suffer from weak detonation capabilities and high E<sub>min</sub> values. Here, the approach is first proposed to design laser ignition primary explosives within the high energy azide and tetrazole-based energetic coordination compounds (ECCs), [Co(N<sub>3</sub>)(2-bmttz)(H<sub>2</sub>O)]<sub>2</sub> 1 and [Co(N<sub>3</sub>)(2-bmttz)(MeOH)]<sub>2</sub> 2 as additives to LA. Material 1e with 4 wt.% of 1 in LA, exhibits ultra-low laser initiation threshold (E<sub>min</sub> = 1.6 mJ) and ultrafast corresponding time (T<sub>min</sub> = 0.2 ms). Specially, compared to LA, the threshold of 1e is as low as 1/1500 of that of LA. Moreover, 30 mg 1e successfully detonates RDX with a laser energy of 1.6 mJ. Theoretical calculations and experiment results reveal that 1 exhibits the superior additive effect compared to 2, attributed to its more enhanced ability to generate free radicals and higher photothermal conversion efficiency under laser conditions. This work represents a paradigm shift, with the potential to develop a laser-driven micro-detonator combining powerful detonation capabilities with exceptionally low laser initiation energy.