Complex beryllium amidoboranes: Structures, stability, and evaluation of their potential as hydrogen storage materials.

Complex beryllium amidoboranes Mx [Be(NH2 BH3 )x+2 ] (M = Li-Cs, x = 1,2) have been computationally studied at M06-2X/def2-TZVPPD//B3LYP/def2-TZVPPD level of theory. Compounds are predicted to be stable at room temperature but release H2 on heating. Agostic Be…HB bonds play an important role in stabilization of oligomeric beryllium imidoboranes. Polymeric imidoborane, hydrogen, and ammonia are expected as major thermal decomposition products of complex beryllium amidoboranes. Ammonia evolution is predicted to proceed at slightly higher temperatures than hydrogen evolution. Based on thermodynamic analysis, Li[Be(NH2 BH3 )3 ] and Li2 [Be(NH2 BH3 )4 ] are the most perspective synthetic targets. Synthetic approaches to these potentially efficient hydrogen storage materials have been proposed. © 2016 Wiley Periodicals, Inc.