Introducing Carborane Clusters into Crystalline Frameworks via Thiol‐Yne Click Chemistry for Energetic Materials

• Published in: Angewandte Chemie International Edition 2024-05, Vol.63 (19), p.e202402363-n/a
• Main Authors: Pu, Tian‐Li, Wang, Xu‐Yang, Sun, Zhi‐Bing, Dong, Xi‐Yan, Wang, Qian‐You, Zang, Shuang‐Quan
• Format: Article
• Language: English
• Subjects: Acetylene; Carborane; Chemical reactions; Chemical synthesis; Delay time; Density functional theory; energetic material; Energetic materials; Ignition; ligand engineering; metal–organic framework; Nitric acid; Oxidizing agents; Porosity; porous coordination polymers
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202402363

Crystalline frameworks represent a cutting‐edge frontier in material science, and recently, there has been a surge of interest in energetic crystalline frameworks. However, the well‐established porosity often leads to diminished output energy, necessitating a novel approach for performance enhancement. Thiol‐yne coupling, a versatile metal‐free click reaction, has been underutilized in crystalline frameworks. As a proof of concept, we herein demonstrate the potential of this approach by introducing the energy‐rich, size‐matched, and reductive 1,2‐dicarbadodecaborane‐1‐thiol (CB−SH) into an acetylene‐functionalized framework, Zn(AIm)2, via thiol‐yne click reaction. This innovative decoration strategy resulted in a remarkable 46.6 % increase in energy density, a six‐fold reduction in ignition delay time (4 ms) with red fuming nitric acid as the oxidizer, and impressive enhancement of stability. Density functional theory calculations were employed to elucidate the mechanism by which CB−SH promotes hypergolic ignition. The thiol‐yne click modification strategy presented here permits engineering of crystalline frameworks for the design of advanced energetic materials. Through thiol‐yne click chemistry, the energy‐rich and reductive carborane subunits were covalently incorporated into the pores of energetic frameworks. This innovative decoration approach enables integrate multiple functionalities, ultimately achieving enhanced energy density, improved safety and shortened ignition delay time of the energetic frameworks.