Ligand shells

Figure 4. A single ligand stabilized Ptsog-cluster between STM tip and an Au( 1 11) facet. The junction between the cluster and the substrate is built up by the ligand shell.

Figure 19. Scheme describing the redox switch, which is based on a viologen redox center incorporated within the nanoclusters ligand shell. For simplification the counterelectrode is not shown. (Adapted with permission from Ref [34], 2000, Nature Publishing Group.)... 

Longoni, G. Iapalucci, M. C. Clusters in ligand shells. Low-valent organometallic clusters. In Clusters and Colloids From Theory to Applications Schmid, G., Ed., VCH New York, 1994 p 91. 

Figure 2.8 SANS measurement of ligand shell thickness as a function of C02 composition for differently sized DDT-stabilized silver nanoparticles dispersed in n-hexane-t/14 [40].

An additional and very attractive aspect of molecular qubits is the fact that they are stable in solution, and that the ligand shell can be functionalized with specific chemical groups. In recent years, this has enabled depositing molecular clusters onto different substrates and grafting them to nanostructures or devices, such as carbon nanotube single electron transistors or point contacts [112]. These devices... 

When it comes to metal-rich compounds of the alkaline earth and alkali metals with their pronounced valence electron deficiencies it is no surprise that both principles play a dominant role. In addition, there is no capability for bonding of a ligand shell around the cluster cores. The discrete and condensed clusters of group 1 and 2 metals therefore are bare, a fact which leads to extended inter-cluster bonding and results in electronic delocalization and metallic properties for all known compounds. 

It follows from the above discussion (sections II. 5,6,7), that the thicker the organic ligand shell and the lower the dielectric constant of the... 

The stability of the Au, cluster compound is of course supplied at least in part by the ligand shell, and this complicates a direct comparison of the above theoretical predictions for imaginary bare Au,. But experimentally, the presence of an MES spectrum consisting of a superposition of distinct lines of the natural linewidth for gold from four different structural sites also constitutes proof that gold core of the Au, cluster is, at least on the time scale of the MES measurements (i.e. 0.1 ps < t < 10 ps) [112,113], a solid up to temperatures of at least 30 K. Surface melting on this time scale can also be refuted for Au, for the same reason. The same has also been observed by MES on the water soluble compound Au, [46],... 

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