Molecular mimetic self-assembly of noble metal nanoclusters

Abstract

Thiolate-protected noble metal nanoclusters (NM-NCs) are ultrasmall particles with a core size of 2 nm or lower. Particles in this size range exhibit strong quantum confinement effects and molecule-like properties such as strong luminescence and enhanced catalytic activity. In this thesis, we present a systematic approach to the self-assembly of NM-NCs into high hierarchy structures with varied structural orderliness, by leveraging on molecule- (atom- or ion-) like structural features of NM-NCs (e.g., small size and uniformity of structure). Negatively charged NM-NCs were first regarded as supramolecular anions, and bridged by divalent counter cations (e.g., Zn2+) into monodisperse spherical assemblies. Amphiphilic NM-NCs (or supramolecular amphiphiles) were then organized into regularly stacked bilayers at liquid-air interface, resembling the formation of lamellar liquid phase by common amphiphiles. Furthermore, deprotonated NM-NCs, which possessed rigid surface and non-directional bonding habit, were regarded as supramolecular atoms and assembled into f.c.c. octahedral supracrystals (SCs) by depletion forces.