Cascade clustering

Rational Screening Set Design and Compound Selection Cascaded Clustering. 

Menard, P.R., Lewis, R.A. and Mason, J.S. (1998a). Rational Screening Set Design and Compound Selection Cascaded Clustering. J.Chem.InfComput.ScL, 38, 497-505. 

Menard PR, Lewis RA, Mason JS (1998) Rational screening set design and compound selection cascaded clustering. J Chem Inf Comput Sci 38 497-505 Young SS, Lam RLH, Welch WJ (2002) Initial compound selection for sequential screening. Curr Opin Drug Discov Devel 5 422-427... 

Ar, Cs, Ga or other elements with energies between 0.5 and 10 keV), energy is deposited in the surface region of the sample by a collisional cascade. Some of the energy will return to the surface and stimulate the ejection of atoms, ions and multi-atomic clusters (figure Bl.25.8). In SIMS, secondary ions (positive or negative) are detected directly with a mass spectrometer. 

Precise placement of metal complexing sites within the infrastructure of a cascade molecule is of importance from a variety of perspectives. In the construction of the above noted Micellane family (cf. Sect. 3.1), we reported the construction of dendrimers with four alkyne moieties at sites equidistant from each other in the interior (17, Fig. 8) [60]. These were treated with decaborane (B10H14) to afford 1,2-dicarba-closo-dodecaboranes (o-carboranes) [71]. Rendering boron clusters soluble in water is of interest because of their use in cancer treatment by Boron Neutron Cancer Therapy. First and second generation water-soluble dendrimers containing four and twelve precisely located boron cluster sites, respectively, were synthesized (e.g., 18). These water soluble dendrimers and their precursors were characterized by 13C-, and nB-NMR spectroscopy (Fig. 8). 

Metal-sulfur clusters probably constitute the best known class of clusters due to their considerable importance and common occurrence in the biological world, where they fulfil the role of electron carriers (see Chapter 12). This function is related to their high capacity to undergo a cascade of reversible redox processes. As an illustrative and introductive example, Figure 1 shows the redox ability of [Fe4(/r3-S)40/-C5H5)4].la... 

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