Luminescent Au(I)–Thiolate Complexes through Aggregation-Induced Emission: The Effect of pH during and Post Synthesis

Abstract

Luminescent Au(I)–thiolate complexes (Au(I)–SR) are synthesized at room temperature using glutathione as both a reducing agent and capping ligand. The photoluminescence (PL) intensity and emission wavelength are found to be strongly affected by the pH environment during and post synthesis. Although there is no Au(0) core present in these complexes, Au(I)–SR exhibit PL which can be further enhanced through an aggregation-induced emission mechanism. The structures of these Au(I)–SR at each pH stage are carefully characterized. Using X-ray absorption fine structure, we further establish a relationship between the PL intensity and degree of aurophilic interactions. We find that the luminescence of Au(I)–SR is tunable over a wide pH range with good reversibility.