Experimental

R factor = 0.033; wR factor = 0.078; data-to-parameter ratio = 11.9. The asymmetric unit of the title compound, [Rb(C7H3N2O6)]n, comprises an Rb cation and a 3,5-dinitrobenzoate anion. The Rb cation is eight-coordinated by O atoms from five 3,5-dinitrobenzoate anions. On the other hand, each 3,5-dinitro-benzoate anion links five Rb cations with the carboxylate groups as 3-bridging. The metal atom is firstly linked by the carboxylate groups into a chain along the c-axis direction, which is further linked by bonds between the Rb and nitro O atoms, giving a three-dimensional framework. Related literature For 3,5-dinitrobenzoate complexes, see: Askarinejad et al. (2007); Madej et al. (2007). For Rb—O bond lengths, see