Abstract: The insertion reactions between CX₂(X=H, F, Cl) and C—H bonds of ethyl methyl ether have been studied at MP2/6 31G(d) level by using ab initio calculation. The potential barriers for three different C—H bonds(namely α'-C—H bonds in methyl group, α-C—H bonds and β-C—H bonds in ethyl group) are 123.8, 32.5, 157.3 kJ/mol(X=Cl) and 254 3, 130 0, 304 2 kJ/mol(X=F) respectively. No potential barrier is present in the insertion reaction between methylene and C—H bonds adjacent to the oxygen atom and the potential barrier for the insertion between methylene and β-C—H bond in ethyl group is 3.4 kJ/mol. C—H bonds of α-C in ethyl group of ethyl methyl ether are the most favourable to CX₂ insertion, C—H bonds in methyl group come next and β-C—H bongs in ethyl group are the most unfavourable.

Key words: Ethyl methyl ether, Carbenes, Insertion reaction, Ab initio