Enhanced luminescence and tunable magnetic properties of lanthanide coordination polymers based on fluorine substitution and phenanthroline ligand†

Abstract

A family of highly stable lanthanide coordination polymers incorporating fluorine-substituted carboxylate tectonics and the rigid ligand phenanthroline, namely, {[Ln _m (Tfbda) _n (Phen) ₂·2H ₂O]·2H ₂O} _z , (Ln = Pr (1), Ho (4) and Gd (7), m = 2, n = 3); {[Ln ₃ (Tfbda) _{m 1} (Tfba) _{m 2} (Phen) _n ·2H ₂O]·H ₂O} _z ( z > 1, Ln = Dy (3), Er (5) and Yb (6), m ₁ = 4, m ₂ = 1, n = 3); [Ln ₂(H ₂Tfbda) ₄(Phen) ₂·(H ₂O) ₂]·Phen (Ln = Nd (2)), Tfbda = 3,4,5,6-tetrafluoro-benzene-1,2-dioic acid, Tfba = 2,3,4,5-tetrafluorobenzoic acid have been afforded under hydrothermal conditions. The series of coordination polymers exhibited diverse structural motifs, from dinuclear cluster to 1-D chain arrary, displaying efficiently sensitized luminescence over a spectral range from visible to near-infrared (NIR) region and a long lifetime, due to efficient energy transfer from fluorine-substituted ligands to Ln( iii) centers in solid state. Slow relaxation magnetization and significant frequency- and temperature-dependent peaks were observed in trinuclear Dy( iii)-based coordination polymer 3. DC magnetic susceptibility studies reveal the existence of weak ferromagnetic interaction within 7.

Abstract

Lanthanide coordination polymers with F-substituted carboxylate tectonics and phenanthroline ligands exhibit emission from the visible to near-infrared region with long lifetime. Dy( iii) compounds show temperature dependent and field induced single molecule magnetism.