The ionic adduct of 1,8-diamino-2,4,5,7-tetranitronaphthalene (DATNN) with 1,8-bis(dimethylamino)naphthalene (DMAN) crystallizes in the triclinic system, space group P1, a = 8.063(3), b = 13.092(3), c = 13.715(3) , α = 118.03, β = 97.19(3), γ = 97.15(3)°, Z = 2. The NHN + hydrogen bonding in the DMAN cation is symmetric, while the NHN - bridge in the DATNN anion is markedly bent and asymmetric. The ν(N-H N) - stretching vibration band in the anion is very weak and broad with the maximum at about 2300 cm - 1 . The ν(N-H N) + band is located at about 500 cm - 1 .