The study of lanthanide complexes has flourished in the last few decades mainly due to their attractive luminescence properties. Numerous ligands have been tailored to improve lanthanide luminescence. We are interested in studying the effect of nitro substitution in different ligand designs on the photophysical and structural characteristics of lanthanide complexes. With this goal we have studied nitro-substituted benzoic acids and their derivatives as ligands. We have now extended the family of nitro-substituted ligands to include the compounds shown in Fig.1. We present their synthesis and photophysical characterization of the Ln(III) complexes.

Fig.1 Nitro-substituted ligands.