Insights into the effect of regulation of molecular composition on the properties of (AuAg) 9 clusters.

The precise tuning of cluster composition helps us to understand the relationship between clusters and their properties. In this context, on the basis of [Au 4 Ag 5 (SAdm) 6 (Dppm) 2 ](BPh 4 ) (HSAdm is 1-adamantanethiol, C 10 H 15 SH; Dppm is bis(diphenylphosphino)methane, Ph 2 PCH 2 PPh 2 ), the control of the internal metal, surface thiol, and surface phosphine ligand was accomplished, with the formations of [Au 6.5 Ag 2.5 (SAdm) 6 (Dppm) 2 ](BPh 4 ), [Au 4 Ag 5 (S-c-C 6 H 11 ) 6 (Dppm) 2 ](BPh 4 ) and [Au 4 Ag 5 (SAdm) 6 (VDPP-2H) 2 ](BPh 4 ) (HS-c-C 6 H 11 is cyclohexanethiol; VDPP is 1,1-bis(diphenylphosphino)ethylene, (Ph 2 P) 2 CCH 2 ; and VDPP-2H is 1,1-bis(diphenylphosphine) ethane derived from the reduction of VDPP, (Ph 2 P) 2 CHCH 3 ). The structures of [Au 6.5 Ag 2.5 (SAdm) 6 (Dppm) 2 ](BPh 4 ) and [Au 4 Ag 5 (S-c-C 6 H 11 ) 6 (Dppm) 2 ](BPh 4 ) were determined by single-crystal X-ray crystallography (SC-XRD), while that of [Au 4 Ag 5 (SAdm) 6 (VDPP-2H) 2 ](BPh 4 ) was confirmed via ESI-MS measurements. The control of the metal, thiol and phosphine ligand affects the electronic structure and optical properties of the [Au 4 Ag 5 (SAdm) 6 (Dppm) 2 ](BPh 4 ) cluster. Overall, the nanoclusters [Au 4 Ag 5 (SAdm) 6 (Dppm) 2 ](BPh 4 ), [Au 6.5 Ag 2.5 (SAdm) 6 (Dppm) 2 ](BPh 4 ), [Au 4 Ag 5 (S-c-C 6 H 11 ) 6 (Dppm) 2 ](BPh 4 ) and [Au 4 Ag 5 (SAdm) 6 (VDPP-2H) 2 ](BPh 4 ) provide a chance to explore the effect of regulation of metals and surface ligands on electronic and optical properties.