Synthesis, radii dependent self-assembly crystal structures and luminescent properties of rare earth (III) complexes with a tripodal salicylic derivative

Five new rare earth complexes with a new flexible tripodal salicylic ligand (H3L), 2,2'-(2-((2-carboxyphenoxy)methyl)-2-(4-methylphenylsulfonamido)propane-1,3-diyl)bis(oxy)dibenzoic acid, of formulae [La2L2(DMF)4]center dot 4DMF center dot 4EtOH center dot 2H(2)O (1), [Eu2L2(DMF)(4)]center dot 2DMF (2), {[GdL(DMF)(H2O)(2)]center dot DMF}(infinity) (3), {[TbL(DMF)(H2O)(2)]center dot DMF}(infinity) (4) and {[YL(DMF)(H2O)(2)]center dot DMF}(infinity) (5) (DMF = N,N-dimethylformamide) have been prepared. The single-crystal X-ray diffraction analysis revealed that complexes 1 and 2 present a cage-like homodinuclear species, while 3-5 show a helical one-dimensional coordination polymer. All these complexes are further connected by hydrogen bonds or p-p interactions, resulting in 3D supramolecular structures. The photophysical properties of the Eu and Tb complexes are investigated in the solid state at room temperature.