1354226-42-8Relevant articles and documents
Synthesis, characterization and photophysical properties of PPh 2-C2-(C6H4)n-C 2-PPh2 based bimetallic Au(i) complexes
Koshevoy, Igor O.,Lin, Chia-Li,Hsieh, Cheng-Chih,Karttunen, Antti J.,Haukka, Matti,Pakkanen, Tapani A.,Chou, Pi-Tai
, p. 937 - 945 (2012/03/10)
A family of the diphosphines PPh2C2(C 6H4)nC2PPh2 (n = 0-3), which possess a dialkynyl-arene spacer between the phosphorus atoms, was used for the synthesis of a series of bimetallic gold(i) complexes 1-7. Unlike the corresponding polynuclear Au(i) clusters, which show unique phosphorescence, 1-7 reveal dual emissions consisting of fluorescence and phosphorescence. The results are rationalized, in a semi-quantitative manner, by the trace (1-3) to zero (4-7) contribution of MLCT varying with the number of conjugated phenylene rings. As a result, unlike typical polynuclear Au(i) clusters with 100% triplet state population, the rate constant of the S1→T1 intersystem crossing is drastically reduced to 109 s-1 (4-7)-1010 s-1 (1-3), so that the fluorescence radiative decay rate can compete or even dominates. The drastic O2 quenching of phosphorescence demonstrates the unprotected nature of the emission chromophores in 1-7, as opposed to the well protected, O2 independent phosphorescence in most multimetallic Au(i) clusters.
