Parallel photoreactions

All these reactions do not proceed stoichiometrically. However, all of them are uniform, that means the partial steps linearly depend on each other. 

The relationship eq. (2.12) cannot be used under these conditions. Each of both the partial steps of the photochemical reactions require their own quantum yield. 

Example 3.16 Parallel photoreaction via the singlet state The reactions steps and the reaction scheme are given by  

Taking into account the linear dependencies of photophysical processes, the overall mechanism can be represented by the gross reactions 

The isomerisation to B and C via the triplet state leads to similar consequences  

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In this type of reaction a single reactant which is excited by absorption of light is able to start more than one gross reaction. The requirement is that the Bodenstein hypothesis can be applied to all intermediates. Whereas in the previous section in the case of the treated parallel photoreactions the gross... 

In the following examples parallel photoreactions starting from the same initial product but including different reactants are treated. 

Example 3-17 One of the parallel photoreactions includes a photoaddition The photoreaction... 

The parallel photoreaction according to the details given in Table 3.5... 

Example 3-22 Parallel photoreaction starting at different components... 

In the case of a parallel photoreaction, in which the two steps are independent of each other... 

Based on Example 3.22 for a parallel photoreaction starting at different components with two linear independent steps... 

In this case all the s linear independent degrees of advancement have to be summed up. The relationship between the different values of can be calculated for simple photoreactions under these conditions. A typical example is a parallel photoreaction as demonstrated in Section 3.1.2. 

In Fig. 5.56 the even more complex photoreaction of diphenyloctatetraene is discussed [187,188]. The reaction chromatogram allows the elucidation of the mechanism with respect to consecutive and parallel photoreactions, which is interesting in comparison with other diphenyl substituted alkene chains. 

Details for simple non-uniform photoreactions 6.6.2.1 Physically sensitised parallel photoreaction... 

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