Dibenzoyl derivative analyses

A variety of procedures were utilized to analyze this reaction mixture and to characterize a,10-diaminopolystyrene. Thin layer chromatographic analysis using toluene as eluent exhibited three spots with Rf values of 0.85, 0.09, and 0.05 which corresponded to polystyrene, poly(styryl)amine and a,w-diaminopolystyrene (see Figure 1). Pure samples of each of these products were obtained by silica gel column Chromatography of the crude reaction mixture initially using toluene as eluent [for polystyrene and poly(styryl)amine] followed by a methanol/toluene mixture (5/100 v/v) for the diamine. Size-exclusion chromatography could not be used to characterize the diamine since no peak was observed for this material, apparently because of the complication of physical adsorption to the column packing material. Therefore, the dibenzoyl derivative (eq. 5) was prepared and used for most of the analytical characterizations. 

Dibenzoyl peroxide and derivs 5 D1186—Dl 188 dibenzoyl peroxide analysis 5 Dl 187 (dibenzoylperoxy)-cyclohexane see Bis (benzoylperoxy)-cyclohexane 2 B135 di-(benzoylperoxy)-dicyclohexylperoxide see Bis (benzoylperoxy)-dicyclohexyl-peroxide 2 B135... 

Because the accuracy of the data for three of the diacyl peroxides is in question, we will attempt to derive enthalpies of formation for them from the reverse of equations 15 and 16. The enthalpy of reaction 15 for dibenzoyl peroxide, using enthalpy of formation values of unquestioned accurac)f, is —400.8 kJmor. This is the same as the ca —398 kJmol for the hquid non-aromatic diacyl peroxides discussed above. Using the solid phase enthalpy of reaction for dibenzoyl peroxide and the appropriate carboxylic acid enthalpies of formation, the calculated enthalpies of formation of bis(o-toluyl) peroxide and bis(p-toluyl) peroxide are —432.2 and —457.6 kJ moU, respectively. From the foregoing analysis, it would seem that the measured enthalpy of formation is accurate for the bis(p-toluyl) peroxide but is not for its isomer. The analysis for dicinnamoyl peroxide is complicated by there being two enthalpies of formation for frawi-cinnamic acid that differ by ca 12 kJmoU. One is from our archival source (—336.9 12 kJmoU ) and the other is a newer measurement (—325.3 kJmol ). The calculated enthalpies of formation of dicinnamoyl peroxide are thus —273.0 and —249.8 kJmoU. Both of these results are ca 80-100 kJmol less negative than the reported enthalpy of formation. 

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