Two novel hydroxide anions bridged lanthanide coordination polymers based on fluorinated carboxylate ligand: Structures, luminescence and magnetic property

Abstract

Two unique lanthanide coordination polymers, namely, {[Ln2(μ3-OH)2(Tfpht)2 (H2O)2·0.5bipy]}n (Ln = Gd (1) and Eu (2), H2Tfpht = 3,4,5,6-Tetrafluorophthalic acid, bipy = 4,4′-bipyridine) have been afforded successfully. The coordination polymers 1 and 2 are isostructural and have the same phase, both crystallizing in the triclinic system, with space group of P−1. They both exhibit one-dimensional (1-D) ribbon-double chains composed of trinuclear lanthanide clusters bridged by μ3-hydroxyl bridges and carboxyl oxygen atoms of Tfpht2− ligands, and the chains are further linked by hydrogen bonding interactions to give rise to a 2-D corrugated layer. The solid state luminescence emission spectra of coordination polymer 1 is based on the H2Tfpht acid ligand, whereas 2 displays the characteristic f-f transitions of Eu(III) ions. The direct-current (dc) magnetic susceptibility studies reveal the weak ferromagnetic interaction between the Gd(III) ions in coordination polymer 1.