Caesium auride
Caesium auride is the inorganic compound with the formula CsAu. It is the Cs+ salt of the unusual Au− anion.Preparation and reactions
CsAu is obtained by heating a stoichiometric mixture of caesium and gold. The two metallic-yellow liquids react to give a transparent product. A solution of CsAu in liquid ammonia is brown, and the solid is yellow. The ammonium adduct is dark blue. Despite being a compound of two metals, CsAu lacks metallic properties since it is a salt with localized charges.
The compound hydrolyzed readily, yielding caesium hydroxide, metallic gold, and hydrogen. Solutions in ammonia undergo metathesis with tetramethylammonium loaded ion exchange resin to give tetramethylammonium auride.
