The strong o donor ability% the e-9' &XI manifests itself in many unusual properties of silicon-containing organic compounds. This review discusses the effect that silicon substituents have on the ground-state properties of organic compounds and on their reactivities, from this viewpoint.

The interaction of 02 with polycrystalline Pd was investigated; above 250 °C a significant amount of oxygen is incorporated into the bulk at pressures far below the dissociation pressure of PdO. The rate of uptake into previously unexposed Pd foil was pressure independent, suggesting (1) that penetration into the bulk occurred from an oxygen-saturated surface and (2) that the rate was limited by the process in which chemisorbed oxygen moved out of the surface layer toward the interior of the Pd. The temperature dependence of the uptake rate in this pressure-independent region was characterized by an Arrhenius A factor of 5.2 X 1020 atoms cm'2 min'1 and an activation energy of 17 kcal mol'1 (71 kJ mol'1). After about 100 monolayers of oxygen were incorporated, the uptake rate began to decline and became unobservable after about 350 monolayers were incorporated. Equilibrium oxygen pressures above such extensively oxygen-treated samples were much lower than the reported dissociation pressures of PdO indicating that the palladium-oxygen system under these conditions should be characterized as a solid solution of oxygen in palladium. The role which this incorporation of oxygen may play in catalytic processes is discussed.

We numerically calculated the full capacitance matrices for both onedimensional (1D) and two-dimensional (2D) quantum-dot arrays. We found it is necessary to use the full capacitance matrix in modeling coupled quantum dot arrays due to weaker screening in these systems in comparison with arrays of normal metal tunnel junctions. The static soliton potential distributions in both 1D and 2D arrays are well approximated by the unscreened (1/r) coulomb potential, instead of the exponential fall-off expected from the often used nearest neighbor approximation. The Coulomb potential approximation also provides a simple expression for the full inverse capacitance matrix of uniform quantum dot arrays. In terms of dynamics, we compare the current-voltage (I-V) characteristics of voltage biased 1D arrays using either the full capacitance matrix or its nearest neighbor approximation. The I-V curves show clear differences and the differences become more pronounced when larger arrays are considered.Typeset using REVT E X 1

A variety of surface-sensitive techniques are used to elucidate the reaction pathways, as well as adsorbate structures, associated with thermal activation of CF3J following adsorption on Ru(001) at 100 K. XPS shows that the C-I bond of CF3I dissociates below 200 K to form CF3(ad) and I(ad); the subsequent reactions of CF2 are best viewed as being regulated by the availability of surface sites. CF3(ad) dissociates to CF2(ad) below 200 K. Further CF3 dissociation, some of which is activated by H(ad), occurs between 200 and 400 K until all available sites are filled. Desorption of the remaining CF3, peaking at 705 K, once again opens surface sites for decomposition. This is followed by recombination of the products to form CF3(g). No evidence for CF(ad) is ever observed. Hydrogen coadsorption studies explain interesting features associated with fluorine evolution. HREELS and ESDIAD results indicate that CF3 adopts a tilted configuration on Ru(001).

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