Acenaphthylene concentration effect

Table 10.3. Solvent and Concentration Effects on the Photodimerization of Acenaphthylene<41)...

The ratio of cis (27) to trans (26) dimers produced in this reaction has been found to be solvent and concentration dependent, as can be seen in Table 10.3. The data in Table 10.3 show that the cis dimer predominates in all three solvents. It is also seen that as the acenaphthylene concentration is increased, proportionally more cis dimer is formed. This effect is slightly more pronounced in cyclohexane than in benzene (see Figure 10.2) Increases in the yield of dimer with increasing concentration would of course be expected... 

The useful ability of micelles to produce high local concentrations of bound organic reactants at low bulk concentrations has been used in photodimerization reactions see references [712, 713] for reviews. The increase in reactant concentration per unit volume of the micelle promotes the probability of encounters between two molecules resulting in up to 1000-fold rate enhancements. The photodimerization of acenaphthylene illustrates this effect nicely cf. Eq. (5-161) [720, 721],... 

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