Poly[(μ-benzene-1,2,4,5-tetra-carboxyl-ato)tetra-silver(I)].

In the centrosymmetric title compound, [Ag(4)(C(10)H(2)O(8))](n), the benzene ring has irregular bond lengths but remains planar (r.m.s. deviation 0.0002 Å). The Ag-O bond lengths are in the range 2.153 (3)-2.615 (4) Å. The carboxyl-ate groups are oriented at dihedral angles of 26.4 (5) and 74.9 (4)° to the benzene ring. The coordination behaviour of each carboxyl-ate O atom is different: in one carboxylate, the O atoms are coordinated to a single and two Ag atoms; in the other carboxylate, the O atoms are coordinated to two and three Ag atoms. Non-classical inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure. The title compound forms a three-dimensional polymeric network due to the coordination of the Ag atoms.