Analysis and Applications of Electronic Structure in Gold and Silver Nanoclusters

Abstract

Gold and silver nanoclusters are understood as atomically precise particles that consist of a metal core of more than 2 atoms that are usually protected and stabilized by a monolayer of organic molecules; these molecules are called ligands. In this thesis, gold and silver nanoclusters are examined through their electronic structure at the level of density functional theory. New analytical methods are developed and applied by considering the symmetry of the clusters more thoroughly than before. Gold clusters incorporating a new type type of ligand, Nheterocyclic carbenes, are studied with computational methods to explain the experimental findings. The scanning tunnelling microscope image of a large ligandprotected, atomically precise silver cluster is analyzed with the help of density functional theory and a pattern recognition algorithm that has been developed for this study. The results and the new methods both produce a wider understanding of metal nanoclusters and pave the way for research of new types of ligand-protected metal nanoclusters and their applications. Keywords: gold, silver, nanoclusters, symmetry, density functional theory, scanning tunnelling microscopy, N-heterocyclic carbenes