A new Eu(III)/Tb(III) binuclear coordination compound with crown ethers and bridging 4,4′-dipyridyl

A new Eu(III)/Tb(III) binuclear coordination compound with red and yellow emissions in solution and solid state, respectively, has been prepared. The lanthanide (Ln) ions are coordinated to crown ethers (C) and bridged by a dipyridyl (dipy) ligand. Ln/C and Ln/C/dipy complexes were also synthesized as precursors for the bimetallic compounds. The homo- and heterobimetallic Ln(III) complexes were characterized by elemental analysis as well as infra-red, absorption (UV–visible) and emission spectroscopies. The heterobimetallic complex geometry was predicted using the Sparkle/AM1 model and suggested to a chemical environment of very low symmetry around the lanthanide ions (C1), in agreement with the luminescence spectrum. The Eu(III) and Tb(III) complexes display intense red and green emissions, respectively, in the solid state at room temperature.