This study, demonstrates that four tetrazole (CN₄) moieties can coexist by the formation of the [–NN–] linkages to give a C₄N₁₈²⁻ anion, which possesses a high N content (84.0%). The C₄N₁₈²⁻ moiety can be reduced to a C₄N₁₈H³⁻ anion by reaction with hydrazine. Furthermore, the addition of HCl results in a new compound (7) which can generate a C₄N₁₈H₃⁻ salt. The physico-chemical properties of the neutral compounds and their salts were investigated. These compounds were characterized and confirmed by single crystal X-ray diffraction; the structural differences among C₄N₁₈²⁻, C₄N₁₈H³⁻ and C₄N₁₈H₃⁻ were studied. Theoretical analysis and experiments showed that these new compounds exhibit high thermal stability (T_d: 165–202 °C) and high detonation velocity (D: 8750–9332 m s⁻¹), which are comparable with those of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX). The structure–property relationship was studied through careful investigation of the noncovalent interactions. The high energetic performance and short preparation steps endow these high-energy-density materials with great potential for practical applications.