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

Abstract

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]·4DMF·4EtOH·2H₂O (1), [Eu₂L₂(DMF)₄]·2DMF (2), {[GdL(DMF)(H₂O)₂]·DMF}_∞ (3), {[TbL(DMF)(H₂O)₂]·DMF}_∞ (4) and {[YL(DMF)(H₂O)₂]·DMF}_∞ (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 π–π interactions, resulting in 3D supramolecular structures. The photophysical properties of the Eu and Tb complexes are investigated in the solid state at room temperature.