Trinitromethyl/trinitroethyl substituted CL-20 derivatives: structurally interesting and remarkably high energy.

A series of trinitromethyl/trinitroethyl substituted derivatives of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5,5,0, 0(3.11),0(5.9)] dodecane (CL-20) were designed and investigated by theoretical methods. Intramolecular interactions between the trinitromethyl/trinitroethyl and the cage were investigated. The effects of trinitromethyl/trinitroethyl groups on stability of the parent compound are discussed. The results reveal a mutual influence of bond length and dihedral angle between the trinitromethyl and the cage. Compared to CL-20, the sensitivity of derivatives is barely affected. Properties such as density, heat of formation and detonation performance of these novel compounds were also predicted. The introduction of the trinitromethyl group can significantly enhance the oxygen balance, density and detonation properties of the parent compound. The remarkable energy properties make these novel cage compounds competitive high energy density materials.