Pair-wise dimers

The problem of correctly filling the capsules with only productive partners has been addressed by cylindrical capsules, such as (36)2 [49] or (37)2 [50], which can simultaneously hold one large and one small guest, but not two large (not enough room) or two small (too much void space left) ones. For instance, (36)2 accommodates pair-wise carboxylic acid dimers (Figure 3.19) [49]. 

The cross-photodimerization reaction represents a great challenge because it requires D to selectively recognize two different olefins in a pair-wise fashion prior to irradiation, whereas the cross-coupling reaction under standard conditions shows no preference over the homo-coupling. The cross-photodimerization of acenaphthylene with substituted naphthoquinones within D resulted in exclusive formation of the cross syn-dimer only... 

D Evelyn et al. [45] modeled desorption experiments by assuming that the desorption rate was proportional to the density of doubly occupied dimers, taken from the lattice gas model. For large values of E f, most H is paired on doubly occupied sites and desorption is close to first order. As E pair approaches zero, the predicted kinetics become second order. D Evelyn et al. [45] reanalyzed the isothermal measurements of Wise et al. using this model and determined slightly different Arrhenius parameters than obtained from a strictly first-order analysis (E = 54.9 kcal/mol, prefactor = 5.6 X 10 s" ). 

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