Electronic transitions oscillator strength

These observations indicate that the photoluminescence is associated mainly with the cw-stilbene part of the silacyclobutene molecule but that the group on the silicon atom affects the characteristics of the electronic transitions (oscillator strengths, non-radiative paths) by modifying the electron density of the o-bonds at the Silicon. 

Another advance permitted by configuration interaction is a precise calculation of other properties such as the magnetic behaviour under weak fields. The Zeeman effect in PrCb is totally reproduced by the configuration interaction parameters (Garcia and Faucher 1989). Unfortunately, the same parameters permit only partial reproduction of the electronic transition oscillator strength (Garcia and Faucher 1992). 

G. Calzaferri and R. Rytz, Electronic transition oscillator strength by the extended Hueckel molecular orbital method, Journal of Physical Chemistry, vol. 99, no. 32, 12141 pages, 1995. 

To compute the intensity of the vibronic transition, S->-N, all we need do is evaluate the vibronic perturbation AVgj, it is assumed that we have experimental or theoretical knowledge of the energies AE j, hv S —> N), and hv TN) and the electronically allowed oscillator strength f TN). [Experimentally, the latter may be obtained by the evaluation of the area under the absorption curve when its ordinate is the extinction coefficient. e v), and its abscissa is the frequency of absorption, r(cm ), according to the formula / = 4.33 Theoretically, it... 

If the absorption is due to an electronic transition then/, , the oscillator strength, is often used to quantify the intensity and is related to the area under the curve by... 

Wong et al. [9] calculated the wavelengths of the lowest-energy electronic transitions of S2, S3, and of the three most stable isomers of S4 from ab initio MO theory as follows (wavelengths in nm oscillator strengths in parentheses) ... 

Figure 12. Electronic spectra and the results of open-shell PPP-like semiempirical calculations for radical ions. The vertical lines represent the allowed transitions, the wavy lines with arrows the forbidden ones. The right side scales denote the calculated spectral intensities, where f stands for the oscillator strength. Top left the absorption curve (146) redrawn to the log e vs. 0 (cm ) form calculations are taken from (59). Top right taken from (11). Bottom left taken from (143). Bottom right taken from (136), the absorption curve redrawn to the log e vs, 0 (cm" ) form.

The electronic adsorption spectra for the complexes [Ir(OH)6]", where n = 0-2, have been resolved and peak maxima locations, molar extinction coefficients, oscillator strengths, and band half-widths calculated.44 Bands have been assigned in the main part to be one-electron MLCT transitions. Spectrophotometrically determined rate constants for the OH reduction of the IrVI and Irv complexes at 25 °C in 3M NaOH are (2.59 0.09) x 10—3 s—1 and (1.53 0.05) x 10 4 s 1 respectively. The activation energy for the reduction, Irv—>IrIV, is nAkcalmoC1. Cyclic voltammetry and potentiostatic coulometry of [Ir(OEI )r,]2 in 3M NaOH on a Pt electrode show that during the electro-oxidation compounds of Irv and IrVI are formed.45... 

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