Poly[penta-aqua-tetra-kis(μ(2)-nicotinato-κN:O)(perchlorato-κO)lanthanum(III)disilver(I)].

In the title complex, Ag(2)La(C(6)H(4)NO(2))(4)(ClO(4))(H(2)O)(5), the La(III) atom, lying on a twofold rotation axis, is eight-coordinated by four O atoms from four nicotinate (nic) ligands and four water mol-ecules in a distorted square-anti-prismatic coordination geometry. The Ag(I) atom is coordinated in an almost linear fashion by two pyridyl N atoms of two nic ligands. The linear coordination is augmented by weak inter-actions with one O atom from a half-occupied ClO(4) (-) anion and a water mol-ecule lying on a twofold axis. Two Ag(nic)(2) units connect two La atoms, forming a cyclic unit. These units are further extended into an infinite zigzag chain. The chains are bridged by the disordered perchlorate ions via weak Ag-O [2.678 (2) Å] inter-actions. O-H⋯O hydrogen bonds, weak Ag⋯Ag [3.3340 (15) Å] inter-actions and π-π inter-actions between the pyridyl rings [centroid-centroid distance = 3.656 (2) Å] lead to a three-dimensional network.