Self-Regulated Pathway-Dependent Chirality Control of Silver Nanoclusters.

Abstract

Imparting chirality affords additive values, functions and responsiveness in molecular systems including nanoscale materials. Here, we report pathway-dependent chirality control in silver nanoclusters (NCs). The use of enantiomeric ligand, α-dihydrolipoic acid (DHLA), for the synthesis of Ag NCs leads to the preferential formation of one-handed chiral Ag29 (DHLA)12 NCs with intrinsic chirality in the exterior shell composed of a silver-dithiolate framework. Small Lewis base molecules such as pyridine bind to silver atoms in the shell of NC as a guest. The guest binding reverses the relative stability between the right- and left-handed NCs upon a steric interaction with the chiral ligand DHLA in the exterior shell in a kinetic manner, leading to unprecedented chirality inversion in the synthesis of NCs. This mechanism is further extended to the self-regulation or self-replication of chirality through interNC interactions dependent on the concentration in the synthesis of NCs.