Blue-side frequency shift

The HB efficiency depends on v If the func on n( >, ) describing the inhomogeneous broadening has a maximum at cOb = Q the integral in Eq. (65) has a maximum shifted to the blue side regarding Therefore, the ratio in Eq. (65) decreases if the frequency >b moves from the red side to tte blue side of the absorption band. This decreasing takes place at Q/T = const... 

Kasha s tests for identification of n- n and it -> n transitions. Solvent perturbation technique is a useful way to identify transitions as n- n Or it - for complex molecules. While comparing bands of different orbital promotion types in hydioxylic solvents such as water and ethanol with those in hydrocarbon or nonpolar solvents, if the band shifts towards the high frequency or shorter wavelength side (blue-shift) then the transition is probably n -> it. If there is a small red shift, the transition is likely to be 7t -> it. The effect of solvents on the n - re transition in acetone and pyrimidine is shown in the Table 3.3. 

The excited electronic state of the outermost molecular monolayer in anthracene is clearly seen in emission at low temperature. The monolayer next to the surface is blue-shifted by 10 cm-1 and the following one by 2 cm-1. The nature of these blue-shifts is now well understood and is related with the absence of neighbors for molecules located near the surface from the vacuum side. Therefore, for these molecules the gas-condensed matter (G-CM) shift of the electronic transition frequency is smaller than the G-CM shift in the bulk (see Fig. 9.1 we assume that the surface corresponds to the (a, b) plane of the anthracene crystal). For temperatures low compared with the blue-shift, the... 

In Fig. 6a and 6b two different CO - 02 interactions at 90 K on sample E are shown. The admission of O2 at 90 K (solid line) on preadsorbed CO (dotted line) on the sample E (Fig. 6a) produces a very small blue shift of the 2098 cm" band without changes in the intensity, a small erosion of the absorption from the low frequency side, the appearance of a shoulder from the high frequency side, at 2116 cm" (see inset), already assigned to CO coadsorbed... 

Second, apart from the sharp zero-phonon hole in Fig. 10, there is a broad side hole whose maximum is shifted to the blue compared to the laser frequency. The side hole represents molecular and lattice vibrational transitions which are simultaneously bleached with the pure electronic line. From the relative magnitude of the area under the zero-phonon hole and the side hole, we see that the coupling to vibrational transitions is rather strong, as is expected for states with a considerable amount of charge transfer character. 

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