catena-Poly[[[tetraaquapraseodymium(III)]-di-μ-nicotinato-κ2O:N;κ2O:N-disilver(I)-di-μ-nicotinato-κ2N:O;κ2N:O] perchlorate monohydrate]

In the title compound, {[Ag2Pr(C6H4NO2)(4)(H2O)(4)]ClO4 center dot-H2O}(n), the Pr-III atom, lying on a twofold rotation axis, has a distorted square-antiprismatic coordination geometry, defined by four O atoms from four nicotinate (nic) ligands and four water molecules. The Ag-I atom is coordinated in an almost linear fashion by two pyridyl N atoms from two nicotinate ligands. The linear coordination is augmented by weak interactions with three O atoms from one perchlorate anion, one uncoordinated water molecule and one carboxylate group. Two Pr atoms link two {Ag(nic)(2)}(+) units into a ring, which is further extended into an infinite zigzag chain by sharing the Pr atoms. These chains are further connected into a three-dimensional network via weak Ag center dot center dot center dot O interactions, O-H center dot center dot center dot O hydrogen bonds, Ag center dot center dot center dot Ag interactions [3.357 (2) angstrom] and pi-pi interactions between the pyridyl rings [centroid-centroid distance = 3.685 (4) angstrom].