A new research program involving the rational design, chemical synthesis, reactivity, and use of alkaline earth metal hydrides as molecular vehicles for the chemical storage of hydrogen is proposed. Due to the earth abundance, low-cost, recyclability, and environmentally non-toxic nature of alkaline earth metals such as magnesium, they serve as promising candidates for hydrogen storage applications. The innovative portion of this proposal employs a neutral ligand strategy for the reversible thermal discharge of hydrogen, affording low-valent molecular complexes which would undergo oxidative addition to reform the hydrogen storage material. Other aspects of hydrogen storage will also be investigated including lowering hydrogen release temperatures, understanding the chemistry of alkaline earth-hydride intermediates?species which typically cannot be observed using traditional methods, and systematically exploring how low-valent alkaline earths react with hydrogen in solution.