Dynamic Origin of Chirality Transfer between Chiral Surface and Achiral Ligand in Au38 Clusters

ACS Nano. 2019 Jun 25;13(6):7127-7134. doi: 10.1021/acsnano.9b02552. Epub 2019 Jun 14.

Abstract

The transfer of chirality between nanomolecules is at the core of several applications in chiral technology such as sensing and catalysis. However, the origin of this phenomenon and how exactly nanoscale objects transfer chirality to molecules in their vicinity remain largely obscure. Here, we show that the transfer of chirality for the intrinsically chiral gold cluster Au38(SR)24 is site dependent; that is, it differs depending on the ligand-binding sites. This is closely related to the dynamic nature of the ligands on the cluster surface. Using a combination of NMR techniques and molecular dynamics simulations, we could assign the four symmetry-unique ligands on the cluster. The study reveals largely different conformational dynamics of the bound ligands, explaining the diverse diastereotopicities observed for the CH2 protons of the ligands. Although chirality is a structural property, our study reveals the importance of dynamics for the transfer of chirality.

Keywords: Au(SR); NMR; TOCSY; chiral nanoclusters; chirality transfer; molecular dynamics simulations; monolayer-protected clusters.

Publication types

  • Research Support, Non-U.S. Gov't