Clusters filled

The concept of dynamic silver clusters capable to transfer between molecules was also pointed out recently by Ras et al. for silver clusters prepared by photoactivation using PM A A as scaffold [20], Every specific initial ratio of silver ions to methacrylate unit, Ag+ MAA, results in distinct spectral bands (Fig. 12a, b). Thus, an initial ratio 0.5 1 gives an absorption band at 503 nm, whereas a ratio 3 1 gives a band at 530 nm. The shuttle effect was proven when for a given silver cluster solution with ratio 3 1 and absorption at 530 nm, a blue shift was achieved by the addition of pure PMAA. For instance if the added amount of polymer decreases the ratio Ag+ MAA from 3 1 to 0.5 1, the new optical band will match exactly with the band corresponding to a solution with initial ratio 0.5 1, that is 503 nm (Fig. 12c). The explanation given for this blue shift was the redistribution of the existent silver clusters in PMAA chains over the newly available PMAA chains, in other words that the clusters shuttle from partly clusters-filled chains to empty ones. 

Fig. 2 (a) Snss cluster filled with four Ba cations in Ba]gNa204Sn3io (b) interstitially metal stabilized M Ei2 capped truncated tetrahedra in BaisNa204Sn3io (E = Sn, M = Na), M°NaioSni2 (E = Sn,... 

Polynuclear clusters fill the gap between mononuclear and extended solid transition metal vibronic systems. The applications of the theory of vibronic interaction allow to describe physical and chemical properties of these systems, sometimes directly linked to their application. The Jahn-Teller distortion found for the rhenium clusters defines the architecture of hybrid inorganic-organic materials and, as a result, their electric and magnetic properties. The application of the vibronic theory to the decatungstate cluster elucidates the details of its reactivity in the photocatalytic reaction. The modern DFT methods give a key to the calculations of key parameters of the vibronic theory. In future, we will assist at the combination of these methods with phenomenological approaches leading to the description of vibronic effects in physical and chemical properties of polynuclear clusters from first principles. 

Skeletal structure of some mixed Au/Ag clusters (filled circle, Au open circle, Ag) (a) [Au13Ag12] in [(Ph3P)ioAui3Agi2Br8]SbF6,... 

Nanocables of BN nanotubes filled with Mo clusters are reported by Golberg el al, a The Mo cluster-filled BN nanotubes are prepared by the treatment of CVD grown CNTs with BjO, CuO and MoO, in a N2 atmosphere. It has been proposed that the filling of CNTs with Mo03 precedes the formation of BN tubes on the CNT template. The filling of MoO, is then further reduced to metallic Mo by the carbon of the CNTs. Continuous filling of Mo could not be obtained by this method. 

Fig. 9 Electron transfer per bond A as a function of the difference SV ad in the Madelung potentials (in Hartree per electron) acting on the Ti and O in neutral stoichiometric clusters (filled circles), in bulk rutile Ti02 (plus), and on the TiO2(110) surface (diamonds) (from Ref. 243).

Three Cs atoms (nearest to the three-fold axis) are attached to four inner triangular faces of two adjacent clusters, filling the valleys on the surface of the chain. 

Figure 8.4. Plots of r(C—H) (a) and r(H---N) (b) versus 1/n for linear and cyclic clusters of HCN and HC3N. Linear clusters filled symbols cyclic clusters open symbols squares (HCN) circles (HC3N) .

FIGURE 1.159 The distribution functions of (a) pore sizes of A-300 and MS calculated using the nitrogen adsorption-desorption isotherms with the SCV/SCR model, and (b) unfrozen water clusters filled voids in hydrated powders and aqueous suspensions of A-300, MS and MIX samples. 

FigHre 2-2. Jellium potential for a spherical Na2o cluster. Filled circles indicate electrons occupying the lowest levels the open c e marks the level where an extra electron should go. 

Zhang AM, Dong JL, Xu QH, Rhee HK, Li XL. Palladium cluster filled in inner of carbon nanotubes and their catalytic properties in liquid phase benzene hydrogenation. Catal Today 2004 93-95 347-52. 

Fig. 3 Projection of the multidimensional descriptor space of a set of compounds usually reveals distinct clustering which reflects chemical similarity. Here, each compound is depicted as circle. According views can be obtained either from principal component analysis or cluster analysis. The centroids of each cluster (filled circles) are representative samples and can be used as test set. The remaining compounds form the training set, because they cover the available descriptor space adequately.

Isolated Pd-atoms in sodalite cages obtained by reducing Pd + ions on SI sites were re-oxidized into Pd + cations located on ST sites merely by heating the zeolite in oxygen above 450 K [21]. In the same way, Pd-clusters filling adjacent supercages were re-oxidized into Pd + cations by calcination in oxygen above 470 K [21]. The mechanism of oxidative redispersion of metal clusters into cations involved the participation of zeolite protons ... 

There are otlier teclmiques for mass separation such as tire quadmpole mass filter and Wien filter. Anotlier mass spectrometry teclmique is based on ion chromatography, which is also capable of measuring tire shapes of clusters [30, 31]. In tills metliod, cluster ions of a given mass are injected into a drift tube witli well-defined entrance and exit slits and filled witli an inert gas. The clusters drift tlirough tills tube under a weak electric potential. Since the... 

Fig. 1. Structure adapted hierarchical description of Coulomb interactions in biological macromolecules. Filled circles (level 0) represent atoms, structural units (li vel 1) are surrounded by a single-line border, and clusters (level 2) are surrounded by a double-line border.

A major potential drawback with cluster analysis and dissimilarity-based methods f selecting diverse compounds is that there is no easy way to quantify how completel one has filled the available chemical space or to identify whether there are any hole This is a key advantage of the partition-based approaches (also known, as cell-bas( methods). A number of axes are defined, each corresponding to a descriptor or son combination of descriptors. Each axis is divided into a number of bins. If there are axes and each is divided into b bins then the number of cells in the multidimension space so created is ... 

In this section, we will investigate the structure of clusters produced when the metal oven is filled with one of the alkaline earth metals Ca, Sr, or Ba. 

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