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

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(2)O]·2H(2)O}(z), (Ln = Pr (1), Ho (4) and Gd (7), m = 2, n = 3); {[Ln(3) (Tfbda)(m(1)) (Tfba)(m(2))(Phen)(n)·2H(2)O]·H(2)O}(z) (z > 1, Ln = Dy (3), Er (5) and Yb (6), m(1) = 4, m(2) = 1, n = 3); [Ln(2)(H(2)Tfbda)(4)(Phen)(2)·(H(2)O)(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.