Neutrons to the rescue
Solid materials rich in hydrogen, such as ammonia borane, could help solve the gas storage problem for vehicle fuel cells. Now, a crystal structure of an alternative material, DADB, offers new hope of a stable material that works at lower temperature (85 rather than 110 Celsius).
In research appearing in ChemComm, M. Bowden and colleagues, including Lujan Neutron Scattering Center researcher (LANSCE-LC) Thomas Proffen, point out that the stoichiometry of diammoniate of diborane (DADB) is known, but its actual chemical structure was the subject of some discussion for many years until chemists settled on the borohydride formula after a definitive series of experiments. The crystal structure of this important material, however, has not been known until now.
Researchers at Pacific Northwest National Laboratory (PNNL) and Los Alamos National Laboratory have unraveled the crystal structure by adding neutron powder diffraction data collected on the Neutron Powder Diffractometer at the Lujan Neutron Scattering Center to the mix of available characterization experiments.
Structure of DADB viewed along c axis. The two crystallographically distinct BH4 sites are indicated. Neutrons are particularly well suited to locate Hydrogen (Deuterium).