Poly[diaquabis(μ4-fumarato-κ4O1:O1′:O4:O4′)(μ4-fumarato-κ6O1:O1,O1′:O4:O4,O4′)(μ2-fumaric acid-κ2O1:O4)dipraseodymium(III)

Abstract

The title complex, [Pr2(C4H2O4)3(C4H4O4)(H2O)2]n, was synthesized by reaction of praseodymium(III) nitrate hexa­hydrate with fumaric acid in a water–ethanol (4:1) solution. The asymmetric unit comprises a Pr3+ cation, one and a half fumarate dianions (L 2−), one half-mol­ecule of fumaric acid (H2L) and one coordinated water mol­ecule. The carboxyl­ate groups of the fumarate dianion and fumaric acid exhibit different coordination modes. In one fumarate dianion, two carboxyl­ate groups are chelating with two Pr3+ cations, and the other two O atoms each coordinate a Pr3+ cation. Each O atom of the second fumarate dianion binds to a different Pr3+ cation. The fumaric acid employs one O atom at each end to bridge two Pr3+ cations. The Pr3+ cation is coordinated in a distorted tricapped trigonal–prismatic environment by eight O atoms of fumarate dianion or fumaric acid ligands and one water O atom. The PrO9 coordination polyhedra are edge-shared through one carboxyl­ate O atom and two carboxyl­ate groups, generating infinite praseodymium–oxygen chains, which are further connected by the ligands into a three-dimensional framework. The crystal structure is stabilized by O—H⋯O hydrogen-bond inter­actions between the coordin­ated water mol­ecule and the carboxyl­ate O atoms.