Synthesis and quantum chemical study on 2, 6, 8, 12-tetranitro-2, 4, 6, 8, 10, 12-hexaazaisowurtzitane

2, 6, 8, 12-Tetranitro-2, 4, 6, 8, 10, 12-hexaazaisowurtzitane (TNH₂IW) was synthesized from 2, 6, 8, 12-tetraacetyl-2, 4, 6, 8, 10, 12-hexaazaisowurtzitane (TAIW) by protection, nitration and deprotection. TNH₂IW could also been obtained by reduction of hexanitrohexaazaisowurtzitane (HNIW, CL-20) with SnCl₂. The molecular geometries, electric structures, and thermodynamic properties of TNH₂IW were calculated using the density functional theory (DFT) method at the B3LYP/6-31G^* level. The thermodynamic parameters including heat capacities and entropies were calculated, and also the polynomial functions between thermodynamic parameters and temperature were determined. The accurate heat of formation 461 kJ · mol^-1 of TNH₂IW in gas phase was obtained via designed isodesmic reaction in which the cage and the nitro group have been kept. The data obtained from the present study show a satisfactory detonation performance, with detonation velocity of 9.13 km · s^-1 and detonation pressure of 38.9 GPa, both of which are higher than those of TNT and RDX, not worse than those of HMX counterparts.