Formation of Planar Chiral Platinum Triangles via Pillar[5]arene for Circularly Polarized Luminescence.

Chiral metal-organic complexes hold great promise as new functional materials that exhibit unique stereochemical and optical properties. Here, we report the formation of optically pure pillar[5]arene-based platinum chiral metallacycles. By coordination with 60° and 90° Pt(II) acceptors, planar chiral platinum triangles were self-assembled efficiently and characterized by multiple spectroscopic techniques. Optical studies indicated that these metallacycles had chiral properties: enantiomers showed a negative Cotton effect, and enantiomers exhibited a positive Cotton effect. In addition, these metallacycles also exhibited circularly polarized luminescence.