NOVELTY - Preparing a boron-nitrogen compound comprises: combining an ammonium salt and an ionic compound including a cation and a boron-containing anion in the absence of solvent to form a mixture, agitating the mixture in the absence of a solvent to form a reaction product and separating the boron-nitrogen compound from the reaction product; or agitating the ammonium salt in the absence of solvent, agitating the ionic compound in the absence of solvent, combining the agitated ammonium salt and the agitated ionic compound, agitating the mixture, and separating the boron-nitrogen compound.    USE - The process is useful for preparing boron-nitrogen compounds, which are useful for transportation applications, such as hydrogen-powered automobiles, buses, motorcycles, aircraft, marine vessels, and rockets, for hydrogen storage and for other applications, e.g. construction and agricultural applications including tractors, earth-movers, and forklifts.    ADVANTAGE - The process is cost effective and prepares effective, reliable boron-nitrogen compounds in sufficient yield and purity that have excellent hydrogen storage and release characteristics. The boron-nitrogen compounds are prepared via mechanical agitation in the absence of solvent hence the process minimizes the use of expensive and flammable solvents. The process minimizes the production of hydrogen gas in the presence of such flammable solvents. (I) (preferably ammonia borane) is suitable for systems having an operating temperature of 40-60 degrees C.    DETAILED DESCRIPTION - Preparing a boron-nitrogen compound comprises: combining an ammonium salt and an ionic compound including a cation and a boron-containing anion of formula (B(R1)4-) in the absence of solvent to form a mixture, agitating the mixture in the absence of a solvent to form a reaction product and separating the boron-nitrogen compound from the reaction product; or agitating the ammonium salt in the absence of solvent, agitating the ionic compound in the absence of solvent, combining the agitated ammonium salt and the agitated ionic compound in the absence of solvent to form a mixture, agitating the mixture in the absence of solvent to form a reaction product, and separating the boron-nitrogen compound from the reaction product.    R1 = H, alkyl or aryl.