Pressure-Induced Phase Transition of Hydrogen Storage Material Hydrazine Bisborane: Evolution of Dihydrogen Bonds

Abstract

We report the high-pressure behavior of dihydrogen-bonded hydrogen storage material hydrazine bisborane (BH3N2H4BH3, HBB) via in situ angle-dispersive X-ray diffraction (ADXRD) and Raman spectroscopy in a diamond anvil cell up to 2.0 GPa. A reversible phase transition at 0.4 GPa was confirmed by ADXRD experiments. The Rietveld refinement showed the high-pressure phase was consistent with the crystal structure of α′-phase (low-temperature phase). Through the analysis of structure changes, Raman spectroscopy, and the Hirshfeld surface, we studied the evolution of dihydrogen bonds under high pressure and attributed the pressure-induced phase transition to the distortion and rotation of the NH2–NH2 group. This work will further the understanding of the characteristics of dihydrogen bonds and provide some contribution to future hydrogen storage applications of HBB.