Cycloaurated gold(III) complexes with monoanionic thiourea ligands

• Synthesis of range of new gold(III) thiourea complexes by simple methodology.
• ESI MS identifies wide range of other species, demonstrating method generality.
• Two structural determinations reveal effects of bulky cyclohexyl substitution.

Using a simple one-pot procedure, reaction of cycloaurated gold(III) dihalide complexes [LAuCl2] (L = 2-benzylpyridyl, 2-anilinopyridyl) with trisubstituted thioureas PhNHC(S)NR2 (R = Me, Cy) and Me3N in methanol, followed by addition of excess NaBPh4 gave the salts [LAu{SC(=NR2)NPh}]+BPh4- containing N,S-chelated thiourea monoanion ligands. The compounds were obtained in good yields, and were characterised by ESI MS, elemental microanalysis and in two cases by X-ray structure determinations. The series of complexes was extended by additional microscale reactions of LAuCl2 complexes (L = 2-benzylpyridyl, 2-anilinopyridyl, 2-benzoylpyridyl or picolinamide) with a wide range of trisubstituted thioureas, with products identified by ESI MS.

Reaction of cycloaurated gold(III) complexes [LAuCl2] (L = 2-benzylpyridyl, 2-anilinopyridyl) with a range of tri-substituted thioureas PhNHC(S)NR2 and base gives cationic complexes [LAu{SC(=NR2)NPh}]+ containing four-membered Au–S–C–N rings, isolated as their BPh4- salts.Figure optionsDownload as PowerPoint slide