Electron charge-separation

For many years, chemists have been using theory to determine molecular properties. One property of particular interest is the dipole moment. The dipole moment is a measure of the overall electronic charge separation... 

In ion-solid interactions it is convenient to use cgs units rather than SI units in relations involving the charge on the electron. The usefulness of cgs units is clear when considering the Coulomb force between two charged particles with Z, and Zq units of electronic charge separated by a distance r... 

The atomic unit of length is the radius of the first orbit in Bohr s treatment of the hydrogen atom. It also turns out to be the most probable distance of a Is electron from the nucleus in the hydrogen atom. The atomic unit of energy corresponds to the interaction between two electronic charges separated by the Bohr radius. The total energy of the Is electron in the hydrogen atom equals —0.5 Hartree. In atomic uiuts Planck s constant h = 2n and so h = 1. 

Williams R M, Koeberg M, Lawson J M, An Y-Z, Rubin Y, Paddon-Row M N and Verhoeven J W 1996 Photoinduced electron transfer to Cgg across extended 3- and 11 a-bond hydrocarbon bridges creation of a long-lived charge-separated state J. Org. Chem. 61 5055-62... 

Charge separation Bohr electron 1 Bohr electron = 2.541765 Debye... 

The carbonyl group withdraws rr electron density from the double bond and both the carbonyl carbon and the p carbon are positively polarized Their greater degree of charge separation makes the dipole moments of a p unsaturated carbonyl compounds signifi cantly larger than those of comparable aldehydes and ketones... 

An electric dipole consists of two equal and opposite charges separated by a distance. AH molecules contain atoms composed of positively charged nuclei and negatively charged electrons. When a molecule is placed in an electric field between two charged plates, the field attracts the positive nuclei toward the negative plate and the electrons toward the positive plate. This electrical distortion, or polarization of the molecule, creates an electric dipole. When the field is removed, the distortion disappears, and the molecule reverts to its original condition. This electrical distortion of the molecule is caHed induced polarization the dipole formed is an induced dipole. 

Experimental Values of Charge-Generation Efficiencies. In this section the charge-generation efficiencies of many polymeric photoconductors are compared (Table 3). When the experimental data has been fitted to the Onsager model, the initial electron—hole separation distance,... 

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