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-FC6H4S) and C12H25NCAu(2,4-F2C6H3S). 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