"Beryllium borohydride compounds have long been of interest in alternative energy for their potential in hydrogen gas storage, since they have the largest hydrogen capacity of all metal borohydrides. However, the structure of these compounds, and thus how exactly they would store hydrogen, has been a puzzle for over 70 years. Now, Gregory H. Robinson and co-workers at The University of Georgia have discovered the structure of a new beryllium borohydride molecule, ending the long-standing ambiguity (DOI: 10.1021/ja304514f). In the past, scientists have proposed multiple different arrangements for the monomeric boron−beryllium−boron bonds in the gas phase, and the number and position of hydrogen atoms in the structure were also unknown. Additionally, solid beryllium borohydride is known to exist as polymers forming a helix, adding to the confusion about the individual structures. The new beryllium borohydride molecule, stabilized by a carbene ligand, sports a five-coordinate beryllium arranged in a distorted square pyramid. Beryllium borohydrides are known to be highly reactive, even explosive compounds, but Robinson’s molecule is stable for several days on the benchtop. This first unequivocal crystal structure advances the chemical understanding of these types of compounds, opening the way for future development of new systems for hydrogen storage and alternative fuel technology. Leigh Krietsch Boerner, Ph.D." Taken from Journal of the American Chemical Society, 2012, 134, 11299-11300
