In recent years, industries have increasingly demanded novel materials of low density (and, therefore, weight) and high strength. Such materials are required for all kinds of transport, especially for automobile and aviation industries. Lower weight vehicles would allow for reduced fuel consumption, which increases the transportation efficiency (the economical point of view) and a corresponding decrease of emission of pollutants to the atmosphere (the ecological point of view). This is why the development of materials with decreased densities is of great importance. The aim of this study was to develop novel materials as reinforcing elements for metal matrix composites. Boron crystalline compounds are proposed to be used, including the derivatives of higher boron– hydrogen anions BnXn 2- n = 10,12, X = H (in some cases – halogen, for example, Cl) as their respective densities meet the criteria. The study pursued two goals: (i) to develop a method for producing these boron hydrides and (ii) to investigate the structure and properties of these boron hydrides.