Synthesis and crystal structure of 7-nitro-5-sulfo-napthalene-1,4- dicarboxylate acid

The title compound (C₁₂H₁₅NO₁₃S, M _r = 413.31 ) was synthesized by the nitration of napthalene-1,4- dicarboxylate acid in mixed nitric and sulfuric acids. It crystallizes in monoclinic, space group P2₁/c with a = 8.100(1), b = 24.369(3), c = 8.634(1) Å β = 105.380(2)°, V = 1643.1(4) ų, Z = 4, D_c = 1.671 g/cm³, F(000) = 856, μ(MoKα) = 0.273 mm^-1, T = 294(2) K, the final R = 0.0400 and wR = 0.1021 for 2866 observed reflections with I > 2σ(I). In this crystal there exist a number of H-bonds which link the molecules to form a three-dimensional infinite network structure. The thermal decomposition of the title compound was investigated by using TG-DTG and DSC techniques.