NH4AuCl4

Ammonium tetrachloroaurate(III), with the chemical formula NH4AuCl4, is an inorganic compound. It is the ammonium salt of tetrachloroauric acid. This compound typically appears as yellow crystals. It is soluble in water and also in some organic solvents. The compound is an oxidizing agent. NH4AuCl4 can be prepared by reacting gold with aqua regia to form chloroauric acid (HAuCl4), and then reacting this acid with ammonium chloride. Alternatively, it can be synthesized by reacting gold(III) chloride (AuCl3) with ammonium chloride. Ammonium tetrachloroaurate(III) has found applications in the electrodeposition of gold and in chemical synthesis. It is also used as a precursor for the preparation of gold nanoparticles. The compound is considered to be sensitive to light and should be stored accordingly. Decomposition can occur upon heating, releasing volatile products.