Inorganic excimer. Spectroscopy, photoredox properties and excimeric emission of dicyano(4,4′-di-tert-butyl-2,2′-bipyridine)platinum(II)

Abstract

The complex [Pt(dtbipy)(CN)₂](dtbipy = 4,4′-di-tert-butyl-2,2′-bipyridine) has a long-lived intra-ligand (ππ*)³ excited state in fluid solutions (room-temperature lifetime at infinite dilution 3 µs in 1,2-dichloroethane). Excimer emission (maximum 565 nm) and photoinduced cligomerisation have been found for this platinum complex. The measured rate constant for the process [Pt(dtbipy)(CN)₂]*+[Pt(dtbipy)(CN)₂]→[{Pt(dtbipy)(CN)₂}₂]* is 9.0 × 10⁸ dm³ mol^–1 s^–1 in 1,2-dichloroethane at room temperature. The photophysics and photoredox properties of the excited monomer and dimer are discussed.