Pt⋯Pt interaction triggered tuning of circularly polarized luminescence activity in chiral dinuclear platinum(II) complexes

Circularly polarized luminescence (CPL) activity switched by Pt⋯Pt interaction is disclosed in two couples of dinuclear Pt(II) complex enantiomers. Upon varying the length of the bridging ligand, intramolecular metal–metal interaction manipulation is achieved as evidenced from crystal structures. Complex (−)-1 exhibiting strong Pt⋯Pt interaction displays red phosphorescence with a maximum peak at 638 nm, while complex (−)-2 exhibiting weak Pt⋯Pt interaction displays green phosphorescence with a maximum peak at 530 nm. The observed CPL was opposite in sign for the two complexes. TD-DFT simulations further confirmed the influence of the Pt⋯Pt distance on the difference in the electronic optical activities.