Two-Monomer Dynamic Libraries

As an example of the application of Eq. [28], consider the family of cyclic tetramers (t = 4) depicted in Fig. 8. The family consists of six rings, each identified by an index ij where i = 4 and j runs from 1 to 6. The values of pij and tij for each ring are also reported in Fig. 8. 

application of Eq. [28] to the family of cyclic tetramers gives  

It must be remarked that when the extent of reaction in the linear fraction, X, tends to 1, the concentration of each ring Cy tends to the product of its EM value, EM,j, times the corresponding we ht thus, for example [C41] tends to EM41. 

When the cyclic dimers reach their plateau value (x 1), the total monomer (meta + para) concentration is well above the critical concentration. Under this condition, p andp , coincide with the initial mole fractions of the two monomers (equal to 0.5), because the distribution of monomeric units within the linear fraction is always purely statistical, and when the total monomer concentration is well above the CC, the statistical linear fraction overwhelms the nonstatistical contribution of the cyclic fraction. Since the EM values of 12 and 14 (EM21 = 13.4 mM and EM23 = 0.30 mM) were known from previous one-monomer DL experiments (see Section 4.1.3), we can expect that the plateau values for the concentrations of homodimers 12 and 14 are J4 of their EM values, that is, 3.35 mM and 0.075 mM, respectively. The plateau value for concentration of homodimer 12 in the two-monomer system was indeed found to be 3.2 mM which is very close to the estimated value, whereas that of the homodimer 14 was too low to be detected, again in accordance with the estimated low value. Saturation value for the equilibrium concentration of heterodimer 13 was 11.4 mM which corresponds to EM22 = 11.4/0.5 = 22.8 mM. It should be stressed 

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