Syntheses, structures, fluorescence sensing properties and white-light emission of lanthanide coordination polymers assembled from imidazophenanthroline derivative and isophthalate ligands

摘要

Nine new lanthanide coordination polymers, namely, [La-2(MPIP)(2)(1,3-bdc)(3)](n)center dot 5nH(2)O (1) [Nd-2(MPIP)(2)(1,3-bdc)(3)](n)center dot 7nH(2)O (2), [Yb-2(MPIP)(1,3-bdc)(3)](n) (3), [Eu-2(MPIP)(2) (1,3-bdc)(2)(CH3COO)(2)](n) (4), [Ln(2)(MPIP)(2)(1,3-bdc)(2)(NO3)(2)](n)center dot 3nH(2)O (Ln = Tb (5), Gd (6)), [Ln(2)(MPIP)(2)(1,3-bdc)(3)](n)center dot 2nH(2)O (Ln = Dy (7), Ho (8), Er (9)), MPIP = 2-(3-methylphenyl)imidazo(4,5-f)(1,10)-phenanthroline, H-2(1,3-bdc) = benzene-1,3-dicarboxylic acid) have been synthesized under hydrothermal or solvothermal conditions and characterized by IR spectra, elemental analyses, powder X-ray diffraction and single crystal X-ray diffraction. Compounds 1-9 features 1D or 2D lanthanide isophthalate structures bearing large conjugated imidazophenanthroline derivative ligands. The thermal stabilities and luminescence properties of compounds 1-9 were investigated. Based on fluorescence sensing behavior, compounds 4 and 5 display a highly sensitive response toward Fe3+ ion through significant fluorescence quenching. Meanwhile, compound 5 can be used as an indicator to detect acidic and alkali environments. The white light emission was studied by heterogeneous physical mixing components of compounds 1, 4 and 5.