Photoluminescence properties of Gd(III) and Ce(III) lanthanide based metal organic frameworks

Abstract

The Gd(III) and Ce(III) based-MOFs (metal organic frameworks) have been synthesized by hydrothermal method using 1,2,4,5­benzenetetracarboxylate (btec) ligand and characterized by elemental analysis, FT-IR, UV-visible and single-crystal X-ray diffraction. The crystal structure analysis of Gd(III) complex [C 10 H 9 GdO 11 ] ( 1 ) and Ce (III) complex [C 10 H 5 CeO 9 ] ( 2 ) show that the central lanthanide ions are coordinated by nine oxygen atoms in which eight O atoms from btec ligands and one O atom from water molecule for both structures. The nearest non-bonding Gd···Gd distance is 3.928 A while Ce···Ce distance is 4.392 A. Complex 1 and 2 bridged by oxygen atoms of btec ligands are formed in 3D networks via strong hydrogen bonds. Additionally, solid state photoluminescence properties of 1 and 2 at room temperature have been investigated. Under the excitation of UV light, intense cyan-blue emission for complex 1 and blue emission for complex 2 are exhibited in the visible regions.