Improving the emission quantum yield in dinuclear Eu(III) and Tb(III) complexes with 2-fluorobenzoate

The reaction of Ln(NO3)(2)center dot 6H(2)O salts (Ln = Eu and Tb) with an excess of 2-fluorobenzoic acid (H-2FBz) in an ethanol/water mixture allows the isolation of dinuclear compounds with the formula [Ln(2)(mu(2)-2FBz)(4)(2FBz)(2)(H-2FBz)(2)(H2O)(2)] (Ln = Eu (1) and Tb (2), 2FBz = 2-fluorobenzoate). A solid-state photoLuminescence study of complexes 1 and 2 shows the 4f-4f Lanthanide transitions in the visible range with improved emission quantum yields. 1 and 2 are water soluble and photoLuminescence studies have also been performed in water and D2O solutions, showing that the emission due to the 4f-4f electronic transitions is still present. The magnetic behaviors of 1 and 2 are also reported.