A two-dimensional undulating Ag(I) coordination polymer constructed of Ag-C and Ag-O bonds: poly[[[μ3-(5,6-η):κO(2):κO(2)-(±)-(1S,2S,3R,4R)-3-carboxy-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylato]silver(I)] monohydrate].

The title coordination polymer, {[Ag(C(8)H(7)O(5))]·H(2)O}(n), is built from Ag(+) cations and singly protonated dehydronorcantharidin (SP-DNC) anions, with a distorted trigonal-planar geometry at the metal centre. The coordination number of Ag(I) is three (with one Ag-π bond and two Ag-O bonds, one from each of three different SP-DNC ligands), if only formal Ag-ligand bonds are considered, but can be regarded as five if longer weak Ag···O interactions are also included. The two-dimensional corrugated-sheet coordination polymer forms a non-interpenetrating framework with (4.8(2)) topology. Disordered water molecules are sandwiched between the sheets.