Hypergolic Zeolitic Imidazolate Frameworks (ZIFs) as Next-Generation Solid Fuels: Unlocking the Latent Energetic Behavior of ZIFs

We present the first strategy to induce hypergolic behavior, i.e. spontaneous ignition and combustion in contact with an external oxidizer, into metal-organic frameworks (MOFs). The strategy uses trigger acetylene or vinyl substituents to unlock the latent hypergolic properties of linkers in zeolitic imidazolate frameworks, illustrated here by six hypergolic MOFs of zinc, cobalt and cadmium. Varying the metal and linker enabled the modulation of ignition and combustion properties, leading to ultrashort ignition delays (down to 2 ms), on par with popular propellants, but without requiring highly energetic or carcinogenic hydrazine components found in conventional hypergols.