Dehydrobromination: Transition State

Four bonds are changed simultaneously in the transition state structure of the methoxy-catalyzed bimolecular HBr elimination from bromoethane. The C-Br and C-H bonds are breaking and the C=C double bond is forming. In addition, a new O-H bond is formed upon proton tranfer to the base.


Figure. The MP2(full)/6-31+G* optimized structure of the transition state structure for the methoxy-catalyzed bimolecular HBr elimination from bromoethane.