Multidipole interaction in reactions of oxygen with esters of polyhydric alcohols

Abstract

1. Chain propagation in the oxidation of esters proceeds via a reaction of the RH + O2→ R. + HO2. type. The rate constant for initiation of the chains at 423 K is (3.4 ± 0.4)·10−6 liter/mole·sec for CR4, (5.2 ± 0.4)·10−7 liter/mole·sec for C2H5CR3, (2.2 ± 0.7)·10−10 liter/ mole·sec for (CH3)2CR2 (R=CH2OCOCH2CH3), and (9.4 ± 1.0)·10−7 liter/mole·sec for C(CH2-OCOCH3)4. A multidipole-interaction effect is manifested in this reaction. The greater the number of ester groups in the molecule, the more readily each of them reacts with O2. 2. In pentaerythritol tetrapropionate O2 reacts at the α-C-H bond of the acid residue with k=3.1·10−7 liter/mole·sec and at the α-C-H bond of the alcohol residue with k=1.2 × 10−7 liter/mole·sec (423 K).