Role of electrons

Glapis K P and Hwang G S 1998 Pattern dependent charging and the role of electron tunneling Japan. J. Appl. Phys. 37 2281... 

In a subsequent work [182], it was shown that the photoelectrochemical performance of InSe can be considerably improved by means of selective (photo)electrochemical etching. Interestingly, whereas the cleavage vdW plane showed little improvement, the photocurrent in the face parallel to the c-axis was doubled. Note that, in contrast to InSe crystals cleaved in the plane perpendicular to the c-axis that are almost defect free, the crystals cut in the plane parallel to the c-axis contain a high density of defects on their surface which leads to a high rate of electron-hole recombinations and inferior quantum efficiency. The asymmetry in the role of electrons and holes, as manifested, e.g., in the fact that surface holes carry out the selective corrosion of the semiconductor surface in both cleavage orientations, was discussed. 

Let us now return to MMCT effects in semiconductors. In this class of compounds MMCT may be followed by charge separation, i.e. the excited MMCT state may be stabilized. This is the case if the M species involved act as traps. A beautiful example is the color change of SrTiOj Fe,Mo upon irradiation [111]. In the dark, iron and molybdenum are present as Fe(III) and Mo(VI). The material is eolorless. After irradiation with 400 nm radiation Fe(IV) and Mo(V) are created. These ions have optical absorption in the visible. The Mo(VI) species plays the role of a deep electron trap. The thermal decay time of the color at room temperature is several minutes. Note that the MMCT transition Fe(III) + Mo(VI) -> Fe(IV) -I- Mo(V) belongs to the type which was treated above. In the semiconductor the iron and molybdenum species are far apart and the conduction band takes the role of electron transporter. A similar phenomenon has been reported for ZnS Eu, Cr [112]. There is a photoinduced charge separation Eu(II) -I- Cr(II) -> Eu(III) - - Cr(I) via the conduction band (see Fig. 18). 

Toda T, Igarashi H, Watanabe M. 1998. Role of electronic property of Pt and Pt alloys on electrocatalytic reduction of oxygen. J Electrochem Soc 145 4185-4188. 

In Chapter 1 we consider the physical and diemical basis of the method of semiconductor chemical sensors. The items dealing with mechanisms of interaction of gaseous phase with the surface of solids are considered in substantial detail. We also consider in this part the various forms of adsorption and adsorption kinetics processes as well as adsorption equilibria existing in real gas-semiconductor oxide adsorbent systems. We analyze the role of electron theory of chemisorption on... 

The role of electronic theory of chemisorption in developing ideas on effects of adsorption on electrical and physical properties of semiconductor adsorbents. 

Ohal, A. R. Ohkubo, K. Fukuzumi, S. Lucius, R. Mayr, H. Role of electron-transfer processes in reactions of diarylcarbenium ions and related quinone methides with nucleophiles. J. Am. Chem. Soc. 2003, 125, 10960-10912. 

F Song, A Eastwood, S Gilbody, L Duley. The role of electronic journals in reducing publication bias. Med Inf Internet Med 24 223-229, 1999. 

Taraban, M.B., Leshina, T.V., Anderson, M.A., and Grissom, C.B., Magnetic field dependence of electron transfer and the role of electron spin in heme enzymes horseradish peroxidase, J. Am. Chem. Soc.,... 

Sobolewski AL, Domcke W, Hattig C (2005) Tautomeric selectivity of the excited-state lifetime of guanine/cytosine base pairs The role of electron-driven proton-transfer processes. Proc Natl Acad Sci USA 102 17903-17906... 

Sobolewski AL, Domcke W (2006) Role of electron-driven proton-transfer processes in the excited-state deactivation adenine-thymine base pair. J Phys Chem A 110 9031-9038... 

However, others reached more ambiguous conclusions. Gates et al. developed a 2D model based on coupling NO vibration to surface phonons, but ignoring the possible role of electron-hole pairs, and successfully captured... 

Using this model they have tried to look at important chemical processes at metal surfaces to deduce the role of electronic nonadiabaticity. In particular, they have tried to evaluate the importance of electron-hole-pair excitation in scattering, sticking and surface mobility of CO on a Cu(100) surface.36,37 Those studies indicated that the magnitude of energy transferred by coupling to the electron bath was significantly less than that coupled to phonons. Thus the role of electron-hole-pair excitation in... 

Millefiori, S., and A. Millefiori. 1983. On the Relative Stability of Glycine Conformers. The Role of Electron Correlation. J. Mol. Struct. (Theochem) 91, 391-393. 

We can also examine isomeric pairs of H-bonded complexes in which the roles of electron-pair donor and acceptor are reversed, and the mutual dipole orientations are therefore fundamentally altered. As an example, Fig. 5.4 shows the isomeric pair of complexes between ammonia and hydrogen fluoride,... 

Recently, we analyzed the role of electron repulsion relative to bond breaking and antiaromaticity effects on a quantitative basis using Natural Bond Orbital (NBO) analysis.24 Two other destabilizing factors were considered at the initial stage of the cyclization in addition to four-electron repulsion between the filled in-plane acetylenic re-orbitals - distortion/breaking of the acetylenic bonds as a result of their bending, and the fact that, at a distance of ca. 3 A, the in-plane re-orbitals become parallel and reach a geometry that resembles the antiaromatic TS of the symmetry forbidden [2S + 2S] cycloaddition (vide infra). 

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... 

Kinetics ofelectrodes and the role of electrons in atomic transport... 

ROLE OF ELECTRON POWDER DIFFRACTION IN SOLVING STRUCTURES... 

Role of electron powder diffraction in solving structures... 

The influence of DNA on the photo-electron transfer process between a variety of donor-acceptor couples has been examined during the last ten years. For all the systems studied, the metal complex interacts with the DNA and plays the role of electron acceptor or donor in the hydrophobic DNA microenvironment, whereas the other partner of the process, i.e. the reducing or oxidising agent in the ground state, is localised either on the DNA double helix, or does not interact with the nucleic acid and remains in the aqueous phase. Thus three... 

---