Exclusive synthesis of Au11(PPh3)8Br3 against the Cl analogue and the electronic interaction between cluster metal core and surface ligands.

To goldly go…: Exclusive Au11(PPh3)8Br3 (see illustration) formation was obtained by a novel two-phase method, although the molar ratio of Br(-)/Cl(-) was 1:4, as identified by ESI-MS. Interestingly, the interaction of Au11 core electrons with the benzene π electrons of the phosphine ligands was revealed by NMR spectroscopy and optical absorption spectroscopic analyses.