Water-Soluble Chiral Ag Clusters Protected by Monothiol -Acetyl-()-penicillamine Synthesized in One Pot.

Despite significant advances in atomically precise Au clusters with chirality, Ag clusters with the relevant features are still less explored. In this study, we report successful synthesis of chiral Ag clusters protected by water-soluble in one pot, which is carried out by reducing Ag ions in the presence of -acetyl-()-penicillamine (-NAP) and triphenylphosphine (TPP) at 10 °C, yielding the Ag(-NAP) cluster. The obtained cluster is isolable as a solid-state powder. Optical absorption of Ag(-NAP) is almost identical with that of Ag(-DHLA), where DHLA denotes α-dihydrolipoic acid, and magnetic circular dichroism (MCD) results support the similarity of their electronic structures. The anisotropy factor of Ag(-NAP) is comparable to or larger than that of Ag(-DHLA), suggesting that the surface shell structure of Ag(-NAP) is inherently chiral, as has been observed for Ag(-DHLA). Then the use of enantiopure NAP would preferentially lead to a one-handed atomic arrangement in the clusters.