Lanthanide coordination polymers constructed from 5-(1H-tetrazol-5-yl)isophthalic acid ligand: white light emission and color tuning

A series of lanthanide coordination polymers (LnCPs), namely [Ln(TZI) (H2O)(5)](n) (1-5) [Ln = Nd (1), Eu (2), Gd (3), Tb (4) and Sm (5)], were synthesized through the self-assembly of 5-(1H-tetrazol-5-yl)isophthalic acid (H(3)TZI) ligand and lanthanide ions. X-ray crystallographic analysis reveals that compounds 1-5 are isostructural, featuring a 1D double-chain structure. The luminescence spectra in the solid state reveal that compounds 2 and 4 exhibit the characteristic luminescence of Eu(III) and Tb(III) ions, respectively, while compound 3 exhibits much enhanced blue-green emission which is derived from the H(3)TZI ligand. Further, by introducing single dopant Eu(III) and codopants Eu(III)/Tb(III) into the Gd(III) framework, white light emission and color-tunable luminescence from yellow to blue were realized.