Heterometallic gold(i)–thallium(i) compounds with crown thioethers

Abstract

The polymeric Au/Tl compounds [{Au(C₆X₅)₂}Tl]_n (X = Cl, F) react with the crown thioethers 1,4,7-trithiacyclononane ([9]aneS₃), 1,5,8,11-tetrathiacyclotetradecane ([14]aneS₄), and 1,4,7,10,13,16,19,22-octathiacyclotetracosane ([24]aneS₈) in an appropriate molar ratio to afford [{Au(C₆X₅)₂}Tl(L)]₂ [L = [9]aneS₃, X = Cl (1), F (4); L = [14]aneS₄, X = Cl (2), F (5)], [{Au(C₆Cl₅)₂}₂Tl₂([24]aneS₈)]_n (3) or [{Au(C₆F₅)₂}₂Tl₂([24]aneS₈)] (6). X-ray diffraction studies of 3, 4 and 6 reveal polymeric (3) or tetranuclear (4, 6) structures formed via Tl–S bonds and Au⋯Tl or Au⋯Tl and Au⋯Au contacts. All the complexes are luminescent in the solid state, but not in solution, where the metal–metal interactions, which are responsible for the luminescence, are no longer present. DFT calculations on representative model systems of complexes 3, 4 and 6 have also been carried out in order to determine the origin of the electronic transitions responsible for their optical properties.