Site-specific doping of silver atoms into a Au ₂₅ nanocluster as directed by ligand binding preferences

For the first time site-specific doping of silver into a spherical Au 25 nanocluster has been achieved in [Au 19 Ag 6 (MeOPhS) 17 (PPh 3 ) 6 ] (BF 4 ) 2 . It is a 6e system showing quite a different absorption spectrum from [Au 25 (SR) 18 ] − .