Enhancing the Circularly Polarized Luminescence of Europium Coordination Polymers by Doping a Chromophore Ligand into Superhelices.

Lanthanide-based molecular materials showing efficient circularly polarized luminescence (CPL) activity with a high quantum yield are attractive due to their potential applications in data storage, optical sensors, and 3D displays. Herein we present an innovative method to achieve enhanced CPL activity and a high quantum yield by doping a chromophore ligand into a coordination polymer superhelix. A series of homochiral europium(III) phosphonates with a helical morphology were prepared with the molecular formula S -, R -[Eu(cyampH) 3-3n (nempH) 3n ]·3H 2 O ( S / R -Eu-n , n = 0-5%). The doping of chromophore ligand S - or R -nempH 2 into superhelices of S / R -Eu-0% not only turned on the CPL activity with the dissymmetry factor | g lum | on the order of 10 -3 but also increased the quantum yield by about 14-fold. This work may shed light on the development of efficient CPL-active lanthanide-based coordination polymers for applications.