Construction of luminescent gold(I) aryl thiolates via isonitrilegold(I) complexes: Influence of synthetic methodology and the thiolate ligand on structure and properties

Abstract

Gold Thiolate Polymers ([ArSAu]n) were prepared via two synthetic routes - the direct reaction of an aromatic thiolate (ArSH) with HAuCl4, or the reaction of an isonitrilegold(I) chloride complex with a thiolate anion. The former route, which is general to almost all thiols, yields an amorphous and non-luminescent material. The latter route, which is more limited in scope, proceeds via an isonitrilegold(I) thiolate complex and typically yields a crystalline and luminescent material. Addition of electron-donating groups to the thiol aromatic ring leads to more rapid polymer formation and loss of luminescence while addition of electron-withdrawing groups slows or stops polymer formation and leads to a red-shift of the luminescence of the final polymeric materials. Two isonitrilegold(I) thiolate complexes with varying numbers of fluorine substituents on the thiolate aromatic ring were characterized crystallographically - C8H17NCAu(p-FC 6H4S) and C12H25NCAu(2,4-F 2C6H3S). As the fluorination of the aromatic ring increases, no significant changes were observed in the bond lengths of the complexes, however, the intermolecular Au-S distances lengthen while the aurophilic interaction distances decrease. These results suggest clear relationships between the molecular structure and both the supramolecular structure and photophysical properties in these materials. © 2009 Verlag der Zeitschrift für Naturforschung, Tübingen.