Spectral transition assignments

For metal ions having d2, d3, d7, and d8 configurations, the ground state is an F state, but there is an excited P state that has the same multiplicity. For d1 and d7 ions in an octahedral field, the spectroscopic states are the same (except for the multiplicity) as they are for d3 and d8 ions in tetrahedral fields. Therefore, the expected spectral transitions will also be the same for the two types of complexes. The three spectral bands are assigned as follows (Tlg(F) means the Tis state arising from the F spectroscopic state) ... 

Both the semiquantitative and quantitative types of calculation yield energy-level schemes from which, in principle, spectral transition energies may be calculated. Comparison of these schemes with observed electronic spectra should enable an assessment of their relative values to be made however, the spectral data on organometallic molecules are very limited and often qualitative. There are few accurate studies involving polarization data and solvent shifts from which the nature of the observed bands can be classified and since, in most cases, the theoretical schemes of bond levels yield an embarrassing number of transitions, this lack of assignment is serious. 

Table 4.22. Optical spectral (one-electron) transition energies ( ) calculated for manganese oxides using the MS-SCF-ATa method, compared with experimentally observed transitions assigned to charge transfer, crystal field, valence band conduction band and crystal field conduction band transitions...

Figure 7. Spectral contributions of transient electronic configurations triggered by the femtosecond UV excitation of aqueous chloride ions. The relative spectral contributions are obtained from the computed analysis of time-resolved UV-IR femtosecond spectroscopic data. A first photophysical channel, including a non-adiabatic transition from a p-like excited hydrated electron state (e hydV to an s-like ground hydrated electron state. B spectral contributions of two well-defined transient fe Cl pairs. The presence of counterions (Na ) influences the dual behavior of these transient electronic configurations. C Direct identification of the spectral band assigned to near-infrared fe Cl pairs, made by using a cooled Optical Multichannel Analyzer (OMA 4) equipped with CCD detectors (1024 X...

PA at l. 48 eV appeal s instantaneously, shows spectral relaxation to the red, and decays on the same timescale of SE, as shown in Figure 8-9. We assign the observed PA to singlet Bu exciton transitions towards higher lying even parity (A ) states. We can speculate on the nature of this state within the proposed model. A possible candidate for the final slate is the inirachain biexciton. However, its energy level is located below the two-exciton stale by an amount equal to the bind-... 

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