Bright Luminescent Platinum(II)‐Biaryl Emitters Synthesized Without Air‐Sensitive Reagents

Transition‐metal complexes bearing biaryl‐2,2′‐diyl ligands tend to show intense luminescence. However, difficulties in synthesis have prevented their further functionalization and practical applications. Herein, a series of platinum(II) complexes bearing biaryl‐2,2′‐diyl ligands, which have never been prepared in air, were synthesized through transmetalation and successive cyclometalation of biarylboronic acids. This approach does not require any air‐ or moisture‐sensitive reagents and features a simple synthesis even in air. The resulting (Et4N)2[Pt(m,n‐F2bph)(CN)2] (m,n‐F2bph=m,n‐difluorobiphenyl‐2,2′‐diyl) complexes exhibit intense green emissions with high quantum efficiencies of up to 0.80 at 298 K. The emission spectral fitting and variable‐temperature emission lifetime measurements indicate that the high quantum efficiency was achieved because of the tight packing structure and strong σ‐donating ability of bph. Pt complexes made easy: Platinum(II) complexes bearing biaryl‐2,2′‐diyl ligands were synthesized without any air‐ or moisture‐sensitive reagents, such as n‐butyllithium. The prepared complexes exhibited intense green emission with high quantum efficiency of up to 0.80, even at 298 K, because of their tightly packed structure and because of the strong σ‐donating ability of the biaryl ligand.