Electronic transitions responsible for

In an early investigation (66T539) the two highest occupied and the two lowest unoccupied orbitals were calculated on the basis of an extended Hiickel theory to determine the electron transition responsible for the long wavelength UV absorption. An Ai- Bi, [Pg.197]

The weak electron transitions responsible for the color of coordination complexes are correlated with the t2g to eg transition of energy A. The origin of the strong transitions responsible for the deep colors of some complexes of metals in high oxidation states, like the permanganate and the chromate ions, has a different explanation not covered here. 

Chromophore — The part (atom or group of atoms) of a molecular entity in which the electronic transition responsible for a given spectral band is approximately localized. The term arose in the dyestuff industry, referring originally to the groupings in the molecule that are responsible for the dye s color. 

The UV-visible spectra of a number of divalent group IV alkyls and amides have been collected (68, 72) however, the electronic transitions responsible for these bands have not yet been assigned. Listed in Table III are some qualitative observations on the color of the divalent alkyls M[CH(SiMe3 )2 k. 

The separation A = e — Et is called the ligand field splitting parameter. As we shall see in Chapter 12, this parameter is related to the energy of the electronic transitions responsible for the colour of many complexes, because the splitting is usually small enough to involve transitions by absorption of visible radiation. 

The type of electronic transitions, responsible for colour in lanthanides ... 

Table 2.2 Electronic Transitions Responsible for the Hydrogen Spectrum ...

These results with the chromophoric substrates raise an interesting issue regarding the nature of the electronic transition responsible for the Tj, as such observations have now been made on several ThDP enzymes. What is the source of the electronic transition responsible for the transient Ti at 475 nm derived from either 3-PKB or PAA and seen on three different ThDP enzymes, and of the 620 nm transient Ti> observed on BFDC derived from NBFA. The author and coworkers have suggested that the broad absorptions correspond to a CT transition between a donor and acceptor. That ThDP can give such CT bands is not unexpected. The... 

KVV refers to the series of electron transitions responsible for the Auger electron. V refers to electrons coming from the valence band of a solid. 

Physical Properties. The inner transition elements, hke the ordinary transition elements, are paramagnetic (some very highly) and form colored ions. However, the absorption spectra of the colored rare earth ions show narrow bands or lines instead of broad bands. Since the electronic transitions responsible for the color of the rare earth ions are deep within the atom, the absorption lines are not broadened by the electric fields of neighboring ions. Further, the stepwise completion of an electronic shell far... 

Figure 2.15 The d-d electronic transition responsible for the violet color of [Ti(H20)6]. ...

Suggest an electronic transition responsible for the emission at 6710 A. In your answer, you need to indude the electronic states involved (each state is defined by its L and S values). Also, you need to specify the electronic configurations from which the states arise. [Hint The Is electrons are not involved.]... 

The most important spectra are those of transition metal ions or complexes of d"(n=l-9) configuration which usually absorb in the visible/u.v. regions of the electromagnetic spectrum (rarely in the near i.r. region). The electronic transitions responsible for the absorption may be classified into ... 

The interpretation of RAS spectra from single-crystal surfaces is not as straightforward as it is for, for example, XPS. This is because the response of the surface depends on the complex dielectric function (a quantity that is difficult to calculate from first principles even for well-characterized materials) for both the bulk of the sample and the surface region. Also, in common with other techniques that are sensitive to surface electronic structure, the existence of intrinsic surface states and surface-modified bulk states compHcates matters. However, absence of a firm theoretical framework for predicting RAS spectra has not necessarily impeded the application of RAS in various fields. An empirical approach, often supported by other techniques that provide information on the electronic transitions responsible for RAS spectral features, can allow surface changes to be studied even without a complete understanding of the RAS spectra. 

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