Solvent-regulated assemblies of 1D lanthanide coordination polymers with the tricarboxylate ligand

Solvothermal reactions of the tricarboxylic acid ligand, biphenyl-3,3', 5-tricarboxylic acid (H(3)bpta), and rare earth nitrate (Ln(NO3)(3) center dot 6H(2)O)in the presence of KOH or DMF produced eight 1D linear coordination polymers, namely, [La(bpta)(H2O)(5)center dot(H2O)(3)](n) (1), [Pr(bpta)(H2O)(5)center dot(H2O)(2.5)](n) (2), [Nd(bpta)(H2O)(5)center dot(H2O)(1.75)] n (3), [Sm(bpta)(H2O)(5)center dot(H2O)(0.5)](n) (4)and [Ln(bpta)(DMF)(H2O)(3)center dot(H2O)] n [Ln = Eu (5), Gd (6), Tb (7), Dy (8)]. The 1D chain further assembles into a 3D supramolecular network structure through hydrogen bonds and p-p stacking among chains. Complexes 3-5 and 7 display the typical emission spectra for lanthanide-centred luminescence. The optical properties of 5 were analysed in detail and coincide well with the structural properties. The influence of temperature on the luminescence lifetime of 6 has been studied and different non-radiative decay paths have been discussed. The magnetic properties show that 4 and 5 exhibit strong spin-orbit coupling, while weak antiferromagnetic coupling exists in 6