Strickler-Berg relationship

Radiative decay is the inverse of absorption and requires coupling of the two states via either an incident photon, which results in stimulated emission, or the constantly fluctuating radiation field, which results in spontaneous emission. The radiative lifetime is also the inverse of the Einstein A coefficient. This can be calculated from the integrated molar absorption coefficient in the absorption spectrum using the Strickler-Berg relationship [55]. 

Born-Oppenheimer approximation is also valid. Otherwise, the phenomenon of vibronic coupling arises, which gives rise to other approximations (the term vibronic should be reserved to solutions obtained in non-Born-Oppenheimer cases, although is frequently used improperly). From the calculation of transition dipole moments, radiative lifetimes can also be obtained, both in fluorescence and phosphorescence by using the Einstein coefficients (A21) and the Strickler-Berg relationships (Strickler and Berg 1962) ... 

The majority of OPVs shows strong fluorescence. Figure 11.5 depicts the fluorescence quantum yields of 2a-i in CH2C12- The average fluorescence lifetime To of such OPVs decreases with increasing n from 1-2 ns to about 0.5 ns [74]. According to the Strickler-Berg relationship, an enhancement of the radiative decay... 

X 10 s compared with 2.2 x lO s" and 2.8 x 10 s . Application of the disputed refractive index, n, correction further increases the divergence between these data while the theoretical value for kp (2.5 x 10 s ) derived using the Strickler-Berg equation, neglecting n is in close agreement with the gas phase data. The phase effect may be the result of uncertainties in measurement of various parameters, or, more probably interactions in the condensed phase which are not explained by the n relationship. Reported data on CgDg are less extensive than for... 

The Strickler-Berg Equation and Other Relationships Between Absorption and... 233... 

S. J. Strickler and R. A. Berg, Relationship between absorption intensity and fluorescence lifetime of... 

In Strickler and Berg theory, it is assiuned that fluorescence occurs from the original excited state without taking into account possible solvent reorientation and subsequent formation of a new lower energy excited state. Hence, the relationships between absorption and emission spectra may be more complicated than simply following Strickler and Berg theory, and ti may differ from These results indicate the importance of considering the effect of medium on fluorescence properties for these compounds. 

Strickler, S. J., Berg, R. A., Relationship between Absorption Intensity and Fluorescence Lifetime of Molecules, J. Chem. Phys. 1962, 37, 814 822. 

As we noted in Sect. 5.1, the Einstein relationship between absorption and fluorescence (Eq. 5.12) assumes that absorption and emission occur at a single frequency, which is not the case for molecules in solution. However, the overall rate of fluorescence by a molecule with broad absorption and emission bands can be related to the integrated absorption strength by expressions that were developed by Lewis and Kasha [18], Forster [19], Strickler and Berg [20], Birks and Dyson [16] and Ross [21]. 

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