抄録
The equilibrium structures and fragmentations of the protonated butane, aminopropanol, formates, and acetates are studied by semi-empirical MINDO/3 MO method. The results obtained were discussed in relation with the role of the proton. Comparison in the energy barriers leads the following conclusions. 1) The H2 elimination easily occurs in the protonated hydrocarbons, while as for the protonated aminopropanol, H2O loss is favorable. 2) The fragmentations do not always occur from the most stable molecular protonated ion. 3) The olefin elimination from the protonated esters favors the stepwise process via intermediate ion A (HCOOH…H+…CH2=CHR) more than any other processes via ring transition states, resulting in good accord with the observed ratios of the hydrogen migrations in protonated propyl ester.
