Enhanced circularly polarized luminescence dissymmetry of [Ru(bpy) 3 ] 2+ complexes in a 3D chiral framework: a study of transparent thin films.

Circularly polarized luminescence (CPL) plays an important role in the development of advanced optical devices. However, the design of CPL-active materials with a decent dissymmetry factor is still challenging. Here, we report CPL-active transparent thin films made from optically active ruthenium complexes [Ru(bpy) 3 ] 2+ embedded in chiral inorganic frameworks. Due to the unique chiral-in-chiral combination, the obtained [Ru(bpy) 3 ][Zn 2 (C 2 O 4 ) 3 ] displays CPL activity with a dissymmetry factor of 5 × 10 -3 . The CPL measurements show that the luminescence dissymmetry factor can be effectively enhanced by one order of magnitude when an optically active [Ru(bpy) 3 ] 2+ complex is incorporated into a chiral inorganic framework compared to its solution form. This study not only emphasizes the potential of constructing CPL-active thin films with coordination polymers but also points out the importance of introducing extra chiral environment to improve the CPL effect.