*2.2. Synthesis of nBu4N*·*[Au(etdt)2] (***1***)*

The etdt ligands (139 mg; 0.30 mmol) was hydrolyzed with a 25-wt% MeOH solution of tetramethylammonium hydroxide (Me4N·OH) (440 mg; 1.2 mmol) in dry THF at room temperature. The solution was stirred for 30 min, and a reddish-orange intermediate precipitate was obtained as the reaction proceeded. After cooling to –78 ◦C in a dry ice/MeOH bath, a THF solution of nBu4N·[AuCl4] (92 mg; 0.16 mmol) was added dropwise to the reaction mixture. Then, the reaction mixture was warmed to room temperature overnight. The resulting microcrystals were collected by filtration and crystallized from a THF solution of nBu4N·PF6 at room temperature to afford dark-violet single crystals of **1**.
