catena-poly[[silver(I)-μ-[9,10-bis(1H-benzimidazol-1-ylmethyl)anthracene]-κ2N3:N3'] bis(nitrato-κO)silver(I)].

Yellow needle-shaped crystals of the title compound, {[Ag(C(30)H(22)N(4))][Ag(NO(3))(2)]}(n), were obtained by the reaction of AgNO(3) and 9,10-bis(benzimidazol-1-ylmethyl)anthracene (L) in a 2:1 ratio. The asymmetric unit consists of two Ag(I) cations, one half L ligand and one nitrate anion. One Ag(I) cation occupies a crystallographic inversion centre and links two N-atom donors of two distinct L ligands to form an infinite one-dimensional coordination polymer. The second Ag(I) cation lies on a crystallographic twofold axis and is coordinated by two O-atom donors of two nitrate anions to form an Ag(NO(3))(2) counter-ion. The polymeric chains are linked into a supramolecular framework via weak Ag···O [3.124 (5) Å] and Ag···π (2.982 Å) interactions (π is the centroid of an outer anthracene benzene ring). The π interactions contain two short Ag···C contacts [2.727 (6) and 2.765 (6) Å], which can be considered to define Ag-η(2)-anthracene bonding interactions. In comparison with a previously reported binuclear Ag(I) complex [Du, Hu, Zhang, Zeng & Bu (2008). CrystEngComm, 10, 1866-1874], this new one-dimensional coordination polymer was obtained by changing the metal-ligand ratio during the synthesis.