Does core size matter in the kinetics of ligand exchanges of monolayer-protected Au clusters?

The kinetics of exchanges of phenylethanethiolate ligands (PhC2S-) of the monolayer-protected clusters (MPCS) Au(sub 38) (SC2Ph)(sub 24) and Au(sub 140) (SC2 Ph)(sub 53) with p-substituted arylthiols (p-x-PhSH), where X = NO2, Br, CH3, OH3 and OH are compared. The rates of later stages of exchange differ for Au(sub 38) and Au(sub 140) cores.