A study of charge quantization on ligand-stabilized Au₅₅cluster monolayers

Abstract

View the article online for updates and enhancements. Related contentNegative differential resistance and nonclassical capacitive behaviour in networks of metalclusters H Zhang, D Mautes and U Hartmann -Coulomb staircases and quantum size effects in tunnelling spectroscopy on ligand-stabilized metal clusters

DFT Studies of Solvation Effects on the Nanosize Bare, Thiolated, and Redox Active Ligated Au55 Cluster

“…Both isomers exhibit a hexagonal outer layer shape (Figure ) and a diameter value of 1.15 nm that are agreement with X-ray photoelecton spectroscopy, ,, scanning tunneling microscopy, − transmission electron microscopy, , EXAFS, , ENDOR, and impedance spectroscopic , experimental data. , However, as discussed in section below, only the more stable icosahedral structure that has four types of different gold atoms (shown in Figure in different colors) is in agreement with the results of Mossbauer spectroscopy . The cubahedral geometry contains six types of atoms, characterized by specific partial charges (see Supporting Information and Figure S1).…”

“…Our choice of Au 55 (SCH 3 ) 42 that has not been observed experimentally is motivated by the fact that the thiol layer is densely packed and is a good model of the densely packed short self-assembled monolayer that was used in the CV measurements of the redox properties of the bpy ligand by Willner et al 13 We also report on computations Au 55 (SCH 3 ) 32 , a model for the Au 55 (SC 18 ) 32 cluster experimentally identified 8 where the dilution of the ligand shell leads to the formation of Au-S-Au bridges. The formation of such bridges has been reported at the experimental and computational levels for other cluster sizes, for example, Au 102 (SR) 44 20,21 and Au 25 (SR) 18 -22-24 for which crystallographic data are available, and on the EI-MS resolved Au 38 (RS) 24 [25][26][27][28][29] and Au 144 (RS) 60 . 30,31 On the theoretical side, there is an intense research effort to characterize the properties of gold clusters of various sizes, ligand shells, and charge states using both quantum chemistry and solid-state DFT methods 12,21,23,28,[32][33][34][35][36][37][38][39] (for recent reviews, see refs 29,40, and 41 and references therein).…”

Symmetry-Break-Induced Variation Of Energy-Level Degeneracy Observed On Individual Molecules By Low-Temperature STM

“…However one of the major questions -if these clusters can still be regarded as metallic systems or not -could not be answered clearly. Recent photoelectron spectroscopy results are pointing towards non-metallic particles [7], while STS shows charge-quantization effects and an energy-level splitting of the cluster core states in accordance with the theory for small metallic particles [6,8]. In order to exclude the influence of the ligand molecules on the spectroscopic data, one has to obtain information about the energy states of these molecules.…”

“…The latter clusters have been investigated by a variety of methods, including EXAFS spectroscopy [1], specific heat measurements [2], Mössbauer spectroscopy [3], atomic force microscopy [4], scanning tunneling spectroscopy [5,6] and many others. However one of the major questions -if these clusters can still be regarded as metallic systems or not -could not be answered clearly.…”

Negative differential resistance and nonclassical capacitive behaviour in networks of metal clusters

“…The STM images confirm that layers with a thickness of about one cluster are produced. Clusters deposited on Au(111) surfaces exhibit a flat and locally well ordered arrangement, whereas on HOPG, clusters group together such that one can locally find them also in the second and even third layers [12]. At temperatures below 20 K, the clusters can be imaged with molecular resolution [13].…”