How to achieve near unity fluorescence quantum yields on gold(I) benzothiadiazole-based derivatives

The synthesis of three new gold(I) benzothiadiazole derivatives has been carried out by the reaction 4-ethynyl-7-(4-nonylphenyl)benzo[c] [1,2,5]thiadiazole (L) with different gold(I)-PR3 (PR3 = triethylphosphane (2), triphenylphosphane (3) and tri-1-naphthylphosphane (4)) sources their light emitting properties thoroughly investigated. compounds display denoted luminescence fluorescence quantum yields above 80% in all cases except for complex containing bulkiest PNaph3 phosphane. resulting emission is mainly dominated organic 2,1,3-benzothiadiazole moiety (BTD) can be modulated following strategies. On one hand, wavelength these solution ca. 60 nm shifted varying polarity solvents. Interestingly, lifetimes strongly increased changing environment conditions, from water:acetonitrile solutions to dispersion within matrixes. In this way, we have able obtain near unity yields, highest values recorded BTD compounds. effect solvents on changes rationalized help Lippert-Mataga equation multiparametric Kamlet-Taft method analyse excited state polarity.