Structures and Phosphorescence Properties of Triphosphine-Supported Au₂Ag₂ and Au₈Ag₄ Alkynyl Cluster Complexes

Abstract

The synthesis, structure, and phosphorescence properties of two families of triphosphine-supported Au­(I)–Ag­(I) heteronuclear alkynyl cluster complexes with unprecedented Au₂Ag₂ and Au₈Ag₄ cluster structures are described. The phosphorescence emission over the whole visible light region was systematically tuned through modification of the electronic effects in aromatic acetylide ligands to attain bright phosphorescence with different luminescent colors. Introduction of electron-withdrawing CF₃ to phenylacetylides results in the emission spectral blue-shift, while it shows progressive red-shift upon introducing electron-donating Bu^t, OMe, or NMe₂. As demonstrated from both experimental and theoretical studies, the phosphorescence arises primarily from ³LLCT/³IL and Au₂Ag₂/Au₈Ag₄ cluster-centered ³[d→p] transitions