- Gold cluster
Gold clusters in
cluster chemistry are gold-derived materials that can either be discrete molecules or larger colloidal particles. Both types are describes asnanoparticles , with diameters of less than one micrometer.Discrete gold clusters
Well-defined, molecular clusters are known, invariably containing organic
ligand s on their exteriors. Two examples are [Au6CP(C6H5)3)6] 2+ and [Au9(P(C6H5)3)8] 3+. [Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.]Colloidal clusters
Gold clusters can be obtained in colloid form. Such colloids often occur with a surface coating of
alkanethiol s orprotein s. Such clusters can be used inimmunohistochemical staining [Hainfeld, J. F.; Powell, R. D. "New Frontiers in Gold Labeling" The Journal of Histochemistry & Cytochemistry, 2000 ,Volume 48, pages 471–480, [http://www.histochem.org/archives/new%20frontiers%20gold%20labeling2000.pdf Online Article] ] . Evidence has been presented for the existence of hollow golden cages with the partial formula Aun- with n = 16 to 18. ["Evidence of Hollow Golden Cages" Bulusu, S.; Li, X.; Wang, L.-S.; Zeng, X. C. Proc. Natl. Acad. Sci. USA 2006, [http://dx.doi.org/10.1073/pnas.0600637103 Abstract] ] These cluster compounds with diameter of 5.5angstrom are observed in the gas-phase after they have been generated by laser vaporization and can be observed in the gas phase by photoelectron spectroscopy.gold metal nanoparticles (NPs) are characterized by an intense absorption in the visible region, which enhances the utility of these species for the development of completely optical devices. The wavelength of this
surface plasmon resonance (SPR) band depends on the size and shape of the nanoparticles as well as their interactions with the surrounding medium. The presence of this band enhances the utility of gold nanoparticle as building blocks for devices for data storage, ultrafast switching, and gas sensors.External links
* Carbon fullerenes now have metallic cousins, 'hollow golden cages' [http://www.physorg.com/news66932851.html Article at physorg.com]
References
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