ω-Thioacetylalkylphosphonium salts: Precursors for the preparation of phosphonium-functionalised gold nanoparticles

Two new ω-thioacetylalkylphosphonium salts that function as masked cationic alkanethiolate ligands for the stabilisation of gold nanoparticles have been prepared. Both (3-thioacetylpropyl)triphenylphosphonium bromide and (6-thioacetylhexyl)triphenylphosphonium bromide were shown to form water-soluble gold nanoparticles of ca. 5–10 nm in size that are stable for up to six months. The related (3-thioacetylpropyl)diphenylphosphine oxide was also prepared but did not act as a stabilising ligand in gold nanoparticle formation.