Exploring a new class of nanomaterials: Monolayer-protected cluster molecules

Chapter I is an introduction to monolayer-protected cluster (MPC) research. This chapter evaluates the present state of the rapidly emerging field of monolayer-protected cluster (MPC) molecules in regards to their: (i) synthesis and monolayer functionalization, (ii) core and monolayer structure and composition, and (iii) interesting chemical and physical properties of MPCs.; Chapter II describes the synthesis and preparation of water soluble gold clusters protected by monolayers of tiopronin (tiopronin-MPCs) or coenzyme A (CoA-MPCs). The materials described in this chapter were characterized with high resolution transmission electron microscopy, UV-Vis spectroscopy, thermogravimetric analysis, 1H NMR spectroscopy, transmission FTIR, and acid/base titration.; Chapter III is a study of the dynamics of monolayer-protected cluster synthesis. The evolution of hexanethiolate monolayer-protected Au cluster (MPCs) core sizes in a typical synthesis reaction mixture was monitored at fixed time intervals over the course of 125 hours using transmission electron microscopy (TEM) and differential pulse voltammetry (DPV).; Chapter IV is a study of the dynamics of place-exchange reactions on monolayer-protected cluster molecules. The dynamics and mechanism of this reaction were probed by determining its kinetic order and final equilibrium position relative to incoming and initial protecting thiolate ligands.; Chapter V describes the effect of solvent refractive index and core charge on the surface plasmon absorption of alkanethiolate monolayer-protected gold clusters.; Chapter VI describes the controlled and reversible formation of transiently soluble alkanethiolate- and tiopronin-MPC aggregates using Cu+2-carboxylate chemistry to form cluster-Cu+2-cluster linkages. Experiments exploring the diffusional and capacitive properties of tiopronin-MPCs are additionally reported in this chapter.; Chapter VII details studies in which the steric environment of alkanethiolate ligand shells of monolayer-protected gold cluster molecules was investigated using SN2 reaction chemistry.; Chapter VIII shows that amide and ester coupling reactions of o-functionalized monolayer-protected gold cluster molecules (MPCs) is an exceptionally efficient avenue to a diverse variety of poly-functionalized MPCs starting from a small subset of o-functionalized materials.; Chapter IX describes place-exchange and amide-forming coupling reactions with water-soluble tiopronin-MPCs and subsequent characterization of the reaction products by 1H and 31P NMR, capillary electrophoresis, electrochemistry, and fluorescence spectroscopy.