Electron wavelengths

Most cyanines show prominent, hypsochromic vibrational shoulders at shorter wavelength associated with the long-wavelength electronic transition (Fig. 2). These vibrational shoulders include one or two vibrational quanta (0 — 1 0 — 2 ), in addition to the absorption energy at Intensity... 

Tetracyano ligands have been used to bridge between four Ru(NH3)5 moieties. The complexes [ Ru(NH3)5 4(/i-L)] + (L = tetracyanoethene, tetracyano-p-quinodimethane, 1,2,4,5-tetracyano-benzene, 2,3,5,6-tetracyanopyrazine) exhibit intense, long-wavelength electronic absorptions. Oxidation to [ Ru(NH3)5 4(yU-L)] °" " and reduction to [ Ru(NH3)5 4(//-L)] + and [ Ru(NH3)5 4-(/i-L)] + can readily be achieved. The species are fully delocalized with partially reduced ligands or partially oxidized Ru centers. Treatment of [5,10,15,20-tetrakis(4-cyanophenyl)porphyrinato] cobalt(II) or [5,10,15,20-tetrakis(4-cyano-2,6,-dimethylphenyl)porphyrinato]cobalt(II) with [Ru-(NH3)5(0S02CF3)] introduces cyano-bound pendant Ru (NH3)5 groups to the porphyrinato complexes. ... 

Plasma frequencies and the corresponding wavelengths for a range of free-electron densities are given in Table 9.2 the plasma effects mentioned in this section are noted beside the wavelengths (electron-hole droplets will be discussed in Chapter 12). 

See also de Broglie Wavelength Electron Theory and Quantum Number... 

Comprehensive material concerning the calculation of electronic spectra of pseudoazulenes deals with the question of whether these compounds also possess the interesting absorption properties of the azulenes. The calculations show that all unsubstituted pseudoazulenes should possess a long-wavelength electronic transition between 500 and 700 nra. corresponding to an S0 - S, transition with n,n character. For simple representatives of the [b]-series this long-wavelength transition is bathochromically shifted in the order of oxalenes to azalenes to thialenes. 

According to the Forster cycle, if the longest wavelength electronic transition of the deprotonated form is of lower energy compared to that of the protonated form (red-shifted electronic absorption or emission spectrum of the deprotonated form with reference to the protonated-form spectrum), the molecule has enhanced excited-state acidity (i.e., the pK a of the molecule is lower than pKa). Equation (1) provides a quick and effective method for evaluating a molecule for its ESPT behavior. 

Investigations of the photoinduced electron transfer between fullerenes and porphyrines show that electron transfer occur from the porphyrin to 3C o/3C o-Additionally, due to the absorption of the porphyrines at the excitation wavelength, electron transfer from triplet-excited porphyrine to fullerene may occur. Both pathways lead to the radical ion pair, the ratio depends on the ratio of con-... 

Z-value (or polarity parameter Z) — is an index of the ionizing power of a solvent based on the frequency of the longest wavelength electronic absorption maximum of l-ethyl-4-methoxycarbonylpyridinium iodide in the solvent. The Z-value is defined by Z = 2.859 x 104/A where Z is in kcalmol-1 and A is in nm, respectively. 

Spectral Properties. The spectral properties of PVTMSK have an important bearing on the lithographic utility and behavior of this polymer. The IR and UV spectra of solid films of PVTMSK have already been discussed in some detail in our previous paper (11) thus only the salient points will be presented in this chapter. The most characteristic feature in the UV spectrum of PVTMSK is a long-wavelength electronic transition with a maximum at 365 nm (Figure 4). This n — tt transition (19) provides the basis for the photosensitivity of PVTMSK to mid-UV radiation. 

Table 1 Longest-wavelength electronic absorption maxima in CH2CI2 <1998T13257>...

Moreover, the electron-phonon interactions in nanotubes are expected to be weak, due to the small area of the Fermi surface and the relatively large Fermi-wavelength, electronic back scattering from phonons is reduced compared with normal metals [149]. 

Table 3. Low-wavelength electronic absorption maxima of selected polybenzimidazoles...

Figure 13.14. Schematic of laser light incident on a metal particle whose diameter is much smaller than the laser wavelength. Electrons are polarized by the incident field and oscillate at the laser frequency a is the particle diameter, and r is the distance of the molecule from the particle center.

Dimroth-Reichardt ET parameter A measure of the IONIZING POWER (loosely polarity) of a solvent, based on the maximum wave number of the longest wavelength electronic absorption band of... 

Figure 1.6. Schematic representation of electron promotion processes in ionic crystals. At the shortest wavelengths, electrons are promoted to the conduction band and photoconductivity is observed. Exciton formation occurs on promotion to levels below the conduction band, this energetic combination of electron and positive hole does not conduct electricity but may participate in decomposition processes. Electrons or positive holes may also be generated from impurities.

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