Novel Ultrahigh-Energy Materials

This paper reviews the recent work carried out in the field of modern high-energy materials (HEMs) with the emphasis on homoleptic polynitrogen compounds. A large volume of quantum-chemical investigations have predicted the possibility of existence of polynitrogen compounds not only as short-lived transient species but also in the form of isolable discrete molecules. Despite the theoretical speculations, only a few polynitrogen ions are known today in addition to well-entrenched N _1– ³ discovered almost 100 year ago. Extraordinary potential of these green molecules to deliver high amounts of energy in comparison with todays and tomorrows most powerful HEMs, namely, hexanitrohexaazaisowurtzitane (CL-20) and octanitrocubane (ONC), has fuelled the imagination of propellant and explosive engineers and technologists. Research activities are in progress in many quantum-chemical schools to explore the possibility of other promising polynitrogen compounds. After the recent discovery of key synthons/building blocks Mg(N₅)₂, N ₁₊ ⁵ SbF _1– ⁶ , N ₁₊ ⁵ SbF₁₁, N ₁₊ ⁵ , N ₁₊ ⁵ SnF₆, and N ₁₊ ⁵ Sn(CF₃)₄, the wealth of polynitrogen compounds is just waiting to be harvested by the HEMs community. There are ambitious plans all over the globe to realize N₆₀, which only prove a eco-friendly dense powerhouse of energy.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 3, pp. 29–45, May–June, 2005.