Au25 Clusters Containing Unoxidized Tellurolates in the Ligand Shell

We report herein the synthesis and characterization of Au-25 clusters containing tellurolates (TePh) in the ligand shell ([Au-25(TePh)(n)(SC8H17)(18-n)](-); n = 1-18). [Au-25(TePh)(n)(SC8H17)(18-n)](-) clusters were synthesized by reacting [Au-25(SC8H17)(18)](-) with diphenyl ditelluride ((PhTe)(2)) in solution. Characterization of the products by mass spectrometry and X-ray absorption fine structure analysis revealed that the tellurolates in [Au-25(TePh)(n)(SC8H17)(18-n)](-), unlike those in tellurolate-protected gold nanoparticles, were not oxidized. Various experiments on the products and theoretical calculations on related clusters revealed that protection by the tellurolates distorts (expands) the central Au-13 core and decreases the HOMO-LUMO gap of the Au-25 clusters.