Dimethylsulfoxide gold–thallium complexes. Effects of the metal–metal interactions in the luminescence

The heteropolynuclear complexes [AuTl(C6X5)2]n (X = F, Cl) react with dimethylsulfoxide (DMSO) in different molar ratios leading to products of stoichiometry [Tl2{Au(C6F5)2}2{μ-DMSO}3]n (1), and [Tl2{Au(C6Cl5)2}2{μ-DMSO}2]n (2). These complexes have been structurally characterized and can be viewed as extended linear chains built with Tl–Au–Tl units in which the thallium atoms are bridged by the oxygen atoms of DMSO ligands. Additional [Au(C6X5)2]− fragments interact with one or two thallium centres, respectively, giving rise to two different types of metal–metal interactions in each molecule. Both of them show a strong luminescence in solid state and complex 2 also in solution. The thallium–thallium interaction in this complex is considered to be the responsible of its luminescence, which remains in solution.