Gold(I) alkynyl complexes present a growing research field with respect to their very wide range of applications in different areas such as luminescence, molecular recognition, optical switches, electronics and catalysis. Biological applications are also being developed in the recent years, where these complexes are used as therapeutic agents against different illnesses such as cancer cells or malaria. Related to luminescence, a general overview of the different states responsible for the observed emission is also included in this critical review. In some cases, the assignment is complicated due to the influence of the gold(I) atom and its capability to form metal⋯metal interactions (aurophilicity). Although an extensive discussion has been found in the literature related to the luminescent properties of these complexes, to the best of our knowledge there are not reports covering the span of their very interesting applications. The widespread research fields where this kind of complexes could present a key role is presented in this review (119 references).

Gold(i) complexes are an expanding area of investigation due to the possibility of giving rise to supramolecular aggregates with particular morphologies that can be modulated together with their luminescent properties.

The reaction of the water soluble phosphine 1,3,5-triaza-7-phosphaadamantane (PTA) with [Au(CC–C₅H₄N)]_n yields the highly luminescent water soluble [(PTA)Au(4-pyridylethynyl)] complex. A detailed analysis of the compound shows the formation of gel structure giving rise to very long fibers, being the first example reported with such a simple structure.