[{AuTl(C 6 Cl 5 ) 2 (toluene)} 2 (dioxane)]: A striking structure that leads to a blue luminescence

The complex [{AuTl(C6Cl5)2(toluene)}2(dioxane)] displays a structure with the thallium(I) center in an unprecedented trigonal planar environment, showing the shortest Au–Tl interaction ever found, a toluene molecule in a η6-mode and the “disappearance” of the Tl(I) inert pair, usually stereochemically active. These characteristics are responsible for its unusual luminescent behaviour.