Partial charge transfer, basis

The physical significance of the above evaluation of as a basis for estimation of ffads.H s the assumption that chemisorption of H involves formation of a quasi-diatomic M—H bond and that the polarity of this bond is characterized by the electronegativity difference, Xm Xh- Directly determined initial heats of adsorption of H, that is, for -> 0, are found (/4) to be related to d> for transition metals, and this effect originates on account of partial charge transfer in H chemisorption determined by the electron affinity of the metal, -O, and characterized inter alia by Xm - Xh-... 

The basis of the model is shown in Figure 32. Each adsorbate is modeled as a dipole characterized by the distance, X, between the positive and negative charge q and by the partial charge-transfer parameter Xj dehned from the equilibrium ... 

Polarization is produced by the slow rate of at least one of the partial processes in the overall electrode process. If this rate-controlling step is a transport process, then concentration polarization is involved if it is the charge transfer reaction, then it is termed charge transfer polarization, etc. Electrode processes are often classified on this basis. 

A Raman study of metal-metal bonding in [Au(/-Bu2Dtc)]2 was reported. The Au—Au bond order was estimated at about one-fourth of its value in Au2. The metal—metal interaction was rationalized on the basis of charge transfer from the R2Dtc ligands to the Au(I) ions and the partial formation of an Au2 bond (243). 

Each element in a binary ionic compound has a full charge because the atom transferred its electron(s), and so the atom s oxidation number equals the ionic charge. But, each element in a covalent compound (or in a polyatomic ion) has a partial charge because the electrons shifted away from one atom and toward the other. For these cases, we determine oxidation number by a set of rules (Table 4.3, next page you ll learn the atomic basis of the rules in Chapters 8 and 9). 

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