Symmetry and electronic structure of noble-metal nanoparticles and the role of relativity.
Hannu Häkkinen,Michael Moseler,Oleg Kostko,Nina Morgner,Margarita Astruc Hoffmann,Bernd von Issendorff +5 more
TLDR
High resolution UV-photoelectron spectra of cold mass selected Cun, Agn, and Aun- with n=53-58 show that only Cu55- and Ag55- exhibit highly degenerate states, a direct consequence of their icosahedral symmetry, as confirmed by density functional theory calculations.Abstract:
We present high resolution UV-photoelectron spectra of cold mass selected ${\mathrm{C}\mathrm{u}}_{n}^{\ensuremath{-}}$, ${\mathrm{A}\mathrm{g}}_{n}^{\ensuremath{-}}$, and ${\mathrm{A}\mathrm{u}}_{n}^{\ensuremath{-}}$ with $n=53--58$. The observed electron density of states is not the expected simple electron shell structure, but is strongly influenced by electron-lattice interactions. Only ${\mathrm{C}\mathrm{u}}_{55}^{\ensuremath{-}}$ and ${\mathrm{A}\mathrm{g}}_{55}^{\ensuremath{-}}$ exhibit highly degenerate states. This is a direct consequence of their icosahedral symmetry, as is confirmed by density functional theory calculations. Neighboring sizes exhibit perturbed electronic structures, as they are formed by removal or addition of atoms to the icosahedron and therefore have lower symmetries. Gold clusters in the same size range show completely different spectra with almost no degeneracy, which indicates that they have structures of much lower symmetry. This behavior is related to strong relativistic bonding effects in gold, as demonstrated by ab initio calculations for ${\mathrm{A}\mathrm{u}}_{55}^{\ensuremath{-}}$.read more
Citations
More filters
Journal ArticleDOI
Atomically Precise Clusters of Noble Metals: Emerging Link between Atoms and Nanoparticles
TL;DR: Luminescence in the visible region, especially by clusters protected with proteins, with a large Stokes shift, has been used for various sensing applications, down to a few tens of molecules/ions, in air and water.
Journal ArticleDOI
A unified view of ligand-protected gold clusters as superatom complexes
Michael Walter,Jaakko Akola,Olga Lopez-Acevedo,Pablo D. Jadzinsky,Guillermo Calero,Christopher J. Ackerson,Christopher J. Ackerson,Robert L. Whetten,Henrik Grönbeck,Hannu Häkkinen +9 more
TL;DR: A unified view of principles that underlie the stability of particles protected by thiolate or phosphine and halide ligands is provided and is best described by a “noble-gas superatom” analogy.
Journal ArticleDOI
Atomic and electronic structure of gold clusters: understanding flakes, cages and superatoms from simple concepts
TL;DR: This tutorial review attempts to describe the development in understanding the structures of bare and ligand-protected gold clusters over the past decade, based on selected density-functional-theory calculations.
Journal ArticleDOI
Electronic structure methods for studying surface-enhanced Raman scattering.
TL;DR: This critical review highlights recent advances in using electronic structure methods to study surface-enhanced Raman scattering and examples showing how time-dependent density functional theory can be used to gain microscopic insights into the enhancement mechanism.
Journal ArticleDOI
Trends in the structure and bonding of noble metal clusters
TL;DR: In this article, the electronic properties and the geometric structure of noble metal clusters were studied and the trend for the cohesive energy, ionization potentials, electron affinities, and highest accupied and lowest unoccupied molecular orbital gap was analyzed in detail for each noble metal and rationalized in terms of two-and three-dimensional electronic shell models.