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

• Two Eu/Tb-MOFs with H3TCA and H2NDC ligands have been obtained.
• The ancillary ligand is employed to decrease water molecule coordinate numbers.
• 2displays superior quantum yield and lifetime than those of 1.

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=0.335 ms, Φoverall=0.06%).

Synoptic:Two Ln-MOFs (Ln=EuIII, TbIII) with mixed polycarboxylate ligands present different luminescent properties.Figure optionsDownload as PowerPoint slide