Structures and luminescent properties of Tb(III) and Tb(III)–Ni(II) coordination polymers based on pyridyl dicarboxylate

The N,O ligand, namely 5-(pyridin-4-yl)isophthalic acid (LH2), with carboxylic acid groups and pyridyl group separated, prefers to act as a bridging ligand. Its Tb(III) coordination polymer, [TbL(LH)(H2O)2]∞·xH2O (1), and heterometallic Tb(III)–Ni(II) coordination polymer, [TbNiL2(LH)(H2O)]∞·xH2O (2), have been successfully prepared. Complex 1 exhibits a two-dimensional layered structure with (4,4) network leaving all the pyridyl N-donors uncoordinated, while complex 2 has a three-dimensional structure due to coordination of Ni(II) to part of pyridyl N-donors. Both the complexes were characterized by single-crystal X-ray diffraction, X-ray powder diffraction, FT-IR spectroscopy and thermogravimetry analysis. The ligand is capable of sensitizing the Tb(III) ion, and both the complexes emit characteristic visible green luminescence of Tb(III).

Tb(III) and heterometallic Tb(III)–Ni(II) coordination polymers have been synthesized by using 5-(pyridin-4-yl)isophthalic acid as N,O ligand. Their structures were determined by single-crystal X-ray diffraction and their luminescent properties were analyzed.Figure optionsDownload as PowerPoint slideHighlights
► Syntheses of Tb(III) and Tb(III)–Ni(II) coordination polymers based on pyridyl dicarboxylate.
► The lanthanide and transition metal ions have different affinities for the N- and O-donors.
► Dimensional increase is observed from 2D to 3D after Ni(II) is introduced.
► The coordination polymers emit green luminescence of Tb(III).