Tetramethylammonium auride, , is an ionic compound containing tetramethylammonium as cation and gold in a âÂÂ1 oxidation state as anion. It is an example of a compound containing this rare ionic form of gold, and the first auride paired with a cation that is not a metal atom that has been synthesized.
Tetramethylammonium auride can be made from caesium auride dissolved in liquid ammonia reacting with tetramethylammonium chloride or an ion exchange resin.
Tetramethylammonium auride decomposes over the period of a day at room temperature to form gold. However it is stable at âÂÂ55ðC. Crystals are transparent.
The crystal structure is tetragonal with space group P4/nmm. Unit dell dimensions are a = 7.599, c = 5.433 ÃÂ with volume V = 313.7 ÃÂ <sup>3</sup>, Z = 2 formulas per unit cell.