Complex Beryllium Amidoboranes: Structures, Stability, and Evaluation of Their Potential as Hydrogen Storage Materials

Complex beryllium amidoboranes M-x[Be(NH2BH3)(x12)] (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 H-2 on heating. Agostic Be center dot center dot center dot 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(NH2BH3)(3)] and Li-2[Be(NH2BH3)(4)] are the most perspective synthetic targets. Synthetic approaches to these potentially efficient hydrogen storage materials have been proposed. (C) 2016 Wiley Periodicals, Inc.