Intense Red‐Blue Luminescence Based on Superfine Control of Metal–Metal Interactions for Self‐Assembled Platinum(II) Complexes
Daisuke Saito, Tomohiro Ogawa, Masaki Yoshida, Junichi Takayama, Satoshi Hiura, Akihiro Murayama, Atsushi Kobayashi, Masako Kato
Abstract
Abstract A series of assembled Pt II complexes comprising N‐heterocyclic carbene and cyanide ligands was constructed using different substituent groups, [Pt(CN) 2 (R‐impy)] (R‐impyH + =1‐alkyl‐3‐(2‐pyridyl)‐1 H ‐imidazolium, R=Me ( Pt‐Me ), Et ( Pt‐Et ), i Pr ( Pt‐ i Pr ), and t Bu ( Pt‐ t Bu )). All the complexes exhibited highly efficient photoluminescence with an emission quantum yield of 0.51–0.81 in the solid state at room temperature, originating from the triplet metal‐metal‐to‐ligand charge transfer ( 3 MMLCT) state. Their emission colors cover the entire visible region from red for Pt‐Me to blue for Pt‐ t Bu . Importantly, Pt‐ t Bu is the first example that exhibits blue 3 MMLCT emission. The 3 MMLCT emission was proved and characterized based on the temperature dependences of the crystal structures and emission properties. The wide‐range color tuning of luminescence using the 3 MMLCT emission presents a new strategy of superfine control of the emission color.