Gold monoiodide

Gold monoiodide is the inorganic compound of gold and iodine with the formula AuI. It can be synthesized by dissolving gold powder in an aqueous solution of iodine and potassium iodide. With Lewis bases, AuI reacts to give numerous complexes.

Preparation
Gold monoiodide can be obtained by reacting a tetrachloridoauric acid solution with furthermore potassium iodide. It is also possible to produce it by reacting gold and iodine in a protective atmosphere at around 390 °C.

Properties
Gold monoiodide is a yellow, crystalline powder that gradually decomposes upon contact with water, humidity or light. It has a tetragonal crystal structure with the space group P42/ncm (space group no. 138), a = 4.359 Å, c = 13.711 Å.