Synthesis, crystal structure and photoluminescence property of Eu/Tb MOFs with mixed polycarboxylate ligands

Abstract

Lanthanide MOFs, [Eu(TCA)(NDC)·H2O]n (1) and [Tb(TCA)(NDC)·H2O]n (2), have been prepared with the mixed aromatic carboxylate ligands, namely, 4,4′,4″-tricarboxytriphenylamine (H3TCA) and 1,4-naphthalenedicarboxylate (H2NDC). Single-crystal X-ray diffraction analysis reveals that isomorphic 1 and 2 present pillar-layered 3D framework that Eu/Tb(III) bond with carboxylate in various coordination fashions. Optical investigation indicates that the as-prepared compounds feature characteristic luminescence emission bands of Eu/Tb ions in the visible regions at room temperature. Moreover, compound 2 shows a relatively longer luminescence lifetime (τ=0.342 ms) and significantly enhanced quantum yield (Φoverall=11%) comparing with those of 1 (τ=0.335ms, Φoverall=0.06%).