An oxygen-sensitive cyclometalated platinum(II) complex with a triphenylamine modified acetylacetone derivative

[Display omitted] A cyclometalated Pt(II) complex [Pt(ppy)(TPA-dpa)] Pt2 with a triphenylamine (TPA) substituted diphenyl-1,3-propanedionate (dpa) as auxiliary ligand was designed and synthesized. The effects of the TPA moiety on the photophysical, electrochemical and oxygen sensing properties of the corresponding Pt(II) complex were systematically investigated compared with non-TPA-modified complexes [Pt(ppy)(dpa)] Pt1 and Pt(ppy)(acac). The maximum emission wavelength of Pt2 exhibits a notable redshift (71 nm) with respect to Pt(ppy)(acac). More importantly, the lifetime (25.52 µs) of Pt2 is significantly prolonged compared with those of Pt1 (0.32 µs) and Pt(ppy)(acac) (2.60 µs). Pt2 is highly sensitive to molecular oxygen when immobilized in an ethyl cellulose film. In addition, the oxygen sensing films have excellent reversibility during the quenching and recovering processes.