AuI: an alternative and potentially better precursor than AuIII for the synthesis of Au nanostructures

This article provides an overview of current developments with regard to the use of AuI compounds as precursors in the synthesis of Au nanostructures with controlled shapes or morphologies. We begin with a brief description of the difference between AuI and AuIII compounds, followed by a discussion on how the solubility and stability of a AuI compound can be improved by forming a coordination complex with a ligand (X). We then focus on a range of recent studies that have been directed towards the use of AuI-X complexes as precursors to elemental Au, in an effort to produce Au nanostructures with a variety of shapes, including icosahedral nanoparticles, truncated decahedrons, nanowires or nanorods, branched nanostructures, hybrid nanostructures, nanoboxes, nanocages, and nanoframes. In these syntheses, the AuI-X complexes offer a number of attractive features for generating Au nanostructures as compared to the conventional AuIII compounds, mostly due to their differences in oxidation state and aurophilic effect. The ability to control AuI chemistry therefore provides a great opportunity to systematically investigate the syntheses, physical properties, and applications of Au nanostructures.