Gold clusters properties

Valden M, Lai X and Goodman D W 1998 Onset of catalytic activity of gold clusters on titania with the appearance of nonmetallic properties Science 281 1647... 

Attention has been given to the synthesis of bimetallic silver-gold clusters [71] due to their effective catalytic properties, resistance to poisoning, and selectivity [72]. Recently molecular materials with gold and silver nanoclusters and nanowires have been synthesized. These materials are considered to be good candidates for electronic nanodevices and biosensors [73]. 

Bonacic-Koutecky, V., Burda, J., Mitric, R., Ge, M., Zampella, G. and Fantucci, P. (2002) Density functional study of structural and electronic properties of bimetallic silver - gold clusters Comparison with pure gold and silver clusters./oumol of Chemical Physics, 117, 3120-3131. 

Further dramatic changes can happen in chemical reactivities of gold clusters with diameters smaller than 2nm. The contribution of support materials including metal oxides, carbons, and polymers to the genesis of unique catalytic properties may be much greater than in the case of NPs and therefore may provide an expanding new field of research. 

Circular dichroism (CD) is another interesting example of an optical property of the small Au SR clusters. Since the first observation of Schaaff et al. [23,24], several reports have appeared regarding the CD activities of gold clusters protected by chiral thiols such as penicillamine [25] and A-isobutyryl-cysteine [26]. Figure 11 shows the CD spectra of 1-9, which is a good reproduction of the original report by Whetten s group [23,24]. 

Small gold clusters (<100 atoms) have become the subject of interest because of their use as building blocks of nanoscale devices and because of their quantum-size effects and novel properties such as photoluminescence, magnetism, and optical activity [427]. 

S. J. Green, J. J. Stokes, G. D. Wignall, G. L. GUsh, M. D. Porter, N. D. Evans, and R. W. Murray, Alkanethiolate gold cluster molecules with core diameters from 1.5 to 5.2 nm Core and monolayer properties as a function of core size, Langmuir 14,17—30 (1998). 

Electric fleld gradient, 22 214-218 Electroabsorption spectroscopy, 41 279 class II mixed-valence complexes, 41 289, 291, 294-297 [j(jl-pyz)]=+, 41 294, 296 Electrocatalytic reduction, nickel(n) macro-cyclic complexes, 44 119-121 Electrochemical interconversions, heteronuclear gold cluster compounds, 39 338-339 Electrochemical oxidation, of iron triazenide complexes, 30 21 Electrochemical properties fullerene adducts, 44 19-21, 33-34 nickeljll) macrocyclic complexes, 44 112-113... 

We present gold clusters very briefly, because recently there an extensive review [578] on their preparation, properties and applications in various fields was published. 

One area related to gold clusters is the field of nanoparticles and nanoclusters. These materials have actually been known since ancient times when they were used for their esthetic appeal and also for their therapeutic properties in the form of colloidal gold. In recent decades, the field of nanoparticle research has emerged and in-depth research has dealt with the properties and potential applications of these systems. 

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