Structural characterization of ammonia borane and hydrazine bis(borane) encapsulated within zirconium Metal-Organic Frameworks containing heterocyclic linkers

The present proposal focuses on the structural determination of adducts between the lightweight inorganic hydrides ammonia borane (NH3BH3, AB, 19.6 wt.% H) and hydrazine bis(borane) (BH3NH2-NH2BH3, HBB, 16.7 wt.% H) and two zirconium(IV) Metal-Organic Frameworks (MOFs) containing bithiazole and bipyridyl-based organic linkers. AB and HBB are among the most studied materials for chemical hydrogen storage, and their nano-confinement into MOFs pores lowers their H2 release temperature through pyrolysis. The [AB@MOF] and [HBB@MOF] composites will be analyzed through neutron diffraction on deuterated samples (before and after thermal treatment) to unveil the plethora of dihydrogen bonding interactions between protonic and hydridic hydrogen atoms present in the crystal lattice, casting light on the H2 release mechanism. The structural analysis of [AB@MOF] and [HBB@MOF] (before and after pyrolysis) through neutron diffraction data is unprecedented, to our knowledge.