Ligation of 2,6-diphenylbenzenethiol (DppSH) onto Au clusters stabilized by poly(N-vinyl-2-pyrrolidone) and subsequent core etching yielded a single cluster Au₂₅(SDpp)₁₁. High-energy X-ray diffraction measurement showed that Au₂₅ constitutes a core in Au₂₅(SDpp)₁₁. We propose a bi-icosahedral Au₂₅ core whose 22 Au surface atoms are capped directly by 11 bulky arenethiolates.