Synthesis, characterization and photo-physical properties of Eu(III) complexes and its luminescent thin films

Abstract Luminescent chiral europium(III) complexes EuL R Cl 3 ( 1 ) and EuL S Cl 3 ( 2 ) were synthesised [where L R and L S are schiff-base ligands of 2,9-dialdehyde 1,10-phenanthroline and (R) and (S) isomer of 2-amino-3-phenylpropanol]. These europium complexes depicting intense “red luminescence” upon incorporating them in polyvinyl alcohol (PVA) matrices a series of transparent, flexible thin films were fabricated. These complexes 1 , 2 and the films 1a - 1c , 2a - 2c were investigated for their photophysical properties such as radiative ( A RAD ) and non-radiative ( A NR ) decay rates, lifetimes ( τ obs ), radiative lifetime ( τ RAD ), intrinsic quantum yield ( Φ Ln ), energy transfer efficiencies ( Φ sen ) and total quantum yields ( Φ overall ). This PVA material at higher concentration demonstrates an interesting LRET (Luminescence Resonance Energy Transfer) behaviour. Based on the detailed investigation of the photo-luminescent properties, a plausible mechanism was proposed for energy transfer process.