Poly[4-(dimethyl­amino)pyridinium [(μ(6)-5-carboxy­benzene-1,2,4-tricarboxy­ato-κ(6) O (1):O (1′):O (2):O (4):O (4′):O (5))diargentate(I)]]

In the title compound, {(C(7)H(11)N(2))[Ag(2)(C(10)H(3)O(8))]}(n), the polymeric anion consists of two Ag(I) atoms and a Hbtc(3−) ligand (H(4)btc = benzene-1,2,4,5-tetra­carboxylic acid). Each Ag(I) atom is coordinated by four O atoms from three different Hbtc(3−) ligands. The two Ag(I) atoms are bridged by two bidentate carboxyl­ate groups into an Ag(2)O(4) cyclic unit, with an Ag⋯Ag distance of 2.8189 (3) Å. In this way, the Ag atoms are connected by the Hbtc(3−) ligands into an extended two-dimensional layer structure. A three-dimensional network is accomplished through O—H⋯O hydrogen bonds between the anionic layers. The cationic guest Hdmap(+) [dmap = 4-(dimethyl­amino)pyridine] is trapped in the network and adheres to the layer by an N—H⋯O hydrogen bond.