Thaltiri Vikranth, Staples Richard J, Shreeve Jean'ne M
Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343, United States.
Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States.
ACS Appl Mater Interfaces. 2025 Jul 2;17(26):38122-38130. doi: 10.1021/acsami.5c07772. Epub 2025 Jun 19.
High-energy density materials (HEDMs) demand precise structural and energetic control to achieve optimal detonation performance, thermal stability, and insensitivity. Now we report a thermally induced rearrangement in the cine-substitution of 1,3,4-trinitropyrazole with 5-aminotetrazole, resulting in two regioisomeric pyrazole-tetrazole frameworks. At room temperature, nucleophilic substitution at the more reactive tetrazole N1-position gave the kinetic product, 1-(3,4-dinitro-1-pyrazol-5-yl)-1-tetrazol-5-amine (), which undergoes thermal rearrangement to form a C5-NH-linked thermodynamic isomer, -(3,4-dinitro-1-pyrazol-5-yl)-2-tetrazol-5-amine () upon heating via a Dimroth-like rearrangement. To enhance performance and safety, compound was converted into energetic salts, with the hydroxylammonium (, Dv: 9412 m/s) and hydrazinium salts (, Dv: 9441 m/s) exhibiting superior detonation velocities, superior to HMX. Meanwhile, nitration of the kinetic product yielded -(1-(3,4-dinitro-1-pyrazol-5-yl)-1-tetrazol-5-yl)nitramide (), which demonstrated the highest detonation velocity (Dv: 9451 m/s), exceeding HMX, while its energetic salts further improve stability with optimized performance. Additionally, carbonyl azide functionalization of resulted in (3,4-dinitro-1-pyrazol-5-yl)carbamoyl azide (, which displayed the highest detonation properties (Dv: 8799 m/s; P: 33.2 GPa) among carbonyl azides, comparable to RDX. This study highlights thermally controlled regioisomeric switching as a promising strategy for designing safer, high-performance energetic materials.
高能量密度材料（HEDMs）需要精确的结构和能量控制，以实现最佳的爆轰性能、热稳定性和钝感性能。现在我们报道了1,3,4-三硝基吡唑与5-氨基四唑的环取代反应中发生的热诱导重排，产生了两种区域异构体吡唑-四唑骨架。在室温下，亲核取代发生在反应活性更高的四唑N1位，得到动力学产物1-(3,4-二硝基-1-吡唑-5-基)-1-四唑-5-胺（ ），加热时，该产物通过类似迪莫夫重排的过程发生热重排，形成C5-NH连接的热力学异构体-(3,4-二硝基-1-吡唑-5-基)-2-四唑-5-胺（ ）。为了提高性能和安全性，化合物 被转化为含能盐，其中羟铵盐（ ，爆速Dv：9412 m/s）和肼盐（ ，爆速Dv：9441 m/s）表现出优于奥克托今（HMX）的爆速。同时，动力学产物的硝化反应生成了-(1-(3,4-二硝基-1-吡唑-5-基)-1-四唑-5-基)硝酰胺（ ），其爆速最高（Dv：9451 m/s），超过了HMX，而其含能盐进一步提高了稳定性并优化了性能。此外， 的羰基叠氮官能化反应生成了(3,4-二硝基-1-吡唑-5-基)氨基甲酰叠氮（ ），它在羰基叠氮化合物中表现出最高的爆轰性能（Dv：8799 m/s；P：33.2 GPa），与黑索今（RDX）相当。本研究强调了热控区域异构体转换作为设计更安全、高性能含能材料的一种有前景的策略。
