Dimethylcarbonyl oxide, ethylene epoxidation

Dimethyl-2-butene, primary ozonide, 720 Dimethylcarbonyl oxide, ethylene epoxidation,... 

FIGURE 17. Transition structures for the epoxidation of ethylene by carbonyl oxide [A(E- -ZPVE) = 10.2 kcalmoU ] and dimethylcarbonyl oxide [A(E-I-ZPVE) = 10.3 kcalmol" ] optimized at the B3LYP/6-311- -G(d,p) level of theory. Bond lengths given in brackets are at the MP2/6-31G(d) level, and the corresponding barriers are 14.8 and 12.9 kcalmoU ... 

Ethylene epoxidation with unsubstituted carbonyl oxide is ca 5 kcalmol" more exothermic than with dimethylcarbonyl oxide, yielding an even earlier transition state. 

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