Novel 1-D double chain lanthanide complexes: Synthesis, structure and luminescence

Treatment of Ln(NO3)3 · 6H2O with 1, 2-phenylenedioxydiacetic acid (H2PDOA) in ethanol leads to the unusual 1-D double chain complexes {[Ln(PDOA)1.5 (H2O)3] · H2O}n (Ln = Sm (1), Eu (2), Dy (3)), in which the Ln3+ ions are linked by pentadentate and bideatate PDOA ligands in two different directions. The chain looks like a ladder containing two –Ln–O–C–O–Ln– chains and PDOA spacers, which has never been observed in the lanthanide carboxylate complexes, and they exhibit different photoluminescence properties.