Tuesday, May 16, 2006

Joel: Advan. Mat. Update

Luminescence Spectra and Dynamics of Mn-Doped CdS Core/Shell Nanocrystals.
A. Ishtzumt and Y. Kanemitsu
Advan. Mat. (2006)18, 1083.

The overcoating of CdS:Mn nanocrystals by a thin shell of non-doped CdS or ZnS results in remarkably improved photoluminescence properties. The CdS:Mn/CdS and CdS:Mn/ZnS nanocrystals presented in this work (see figure) show a much more efficient Mn-related photoluminescence than the non-coated nanocrystals. These nanocrystals are expected to find applications in flat-panel displays, high-density optical data storage materials, and fluorescence labels for biological imaging

Growing Metal Nanoparticles by Enzymes
I. Willner, R. Baron, B. Willner.
Advan. Mat. (2006)18, 1109.

Enzymes act as catalysts for the growth of metallic nanoparticles (NPs). The enzymemediated growth of metallic NPs provides a general means to follow biocatalyzed transformations, and to develop optical sensors for different substrates such as glucose, L-DOPA, alcohols, lactate or nerve gas analogs. Enzymes modified with Au NPs act as biocatalysts for the fabrication of metallic nanowires. The dip-pen nanolithography of NP-functionalized enzymes on Si surfaces yields biocatalytic templates that enable the orthogonal evolution of nanowires consisting of different metals.

Andre, Joel
Molecular Materials by Self-Assembly of Porphyrins, Phthalocyanince, and Perylenes
J.A.A.W. Elemans, R. van Hameren, J.M. Nolte, A.E. Rowan.
Advan. Mat. (2006)18, 1251.

Porphyrins, phthalocyanines, and perylenes are compounds with great potential for serving as components of molecular materials that possess unique electronic, magnetic and photophysical properties. In general, a highly specific communication between a large number of these chromophores is required in order to express their function to a maximal level, and for this reason it is of importance to construct arrays in which the molecules are organized in well-defined geometries with respect to their neighbors. This review is an account of some recent efforts to construct highly ordered assemblies of porphyrins, phthalocyanines, and perylenes by means of self-assembly in solution and on surfaces, and by attaching them to polymeric scaffolds.

Rob, Interesting Cu(I) complex...
Highly Luminescent Cu(I) Complexes for Light-Emitting Electrochemical Cells.

N. Armaroli, G. Accorst, M. Holler, O. Moudam, J.F. Nierengarten, Z. Zhou, R.T. Wegh, R. Welter.
Advan. Mat. (2006)18, 1313.

Highly luminescent CuI complexes with one phenanthroline and one (bis[2-(diphenylphosphino)phenyl]ether) ligand show an emission quantum yield of up to 28 % upon deactivation of the metal-to-ligand charge-transfer excited states; their X-ray crystal structure shows a distorted tetrahedral geometry (see figure and inside cover). One of these compounds is used as an active material in a light-emitting electrochemical cell; it exhibits an efficiency similar to that of RuII-type complexes.

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