Chemistry of Positive Ions. I. General Theory Particularly for the Radiation Induced Cross Linkage of Polymers and Polymerization of Saturated Hydrocarbons

Abstract

The chemical properties of positive ions are considered to be analogous to those of the corresponding neutral atom or molecule. However, the charge strengthens bonds and provides the long‐ranged attractive polarization force which causes the reaction cross sections to be very large. For organic ions dehydrogenation to form carbonium ions occurs frequently, so in addition to the parent ion radical with its great reactivity as a type of super fluorine atom, the carbonium ions with their extremely acidic (electrophilic) properties cause a wholly different set of reactions. These are analogous to those of carbene and may lead to the radiation‐induced polymerization of saturated aliphatic hydrocarbons. Both ion radicals and carbonium ions can play important roles in the radiation induced cross linkage of polyethylene and other polymers. It is predicted that the effect of phase will be very important in radiation chemistry, because the cage effect of the surrounding close‐packed molecules in the liquid and solid phase, as contrasted with the gas phase, will cause the fragmentation of the parent ions which is so marked in the gas phase to be reversed to a considerable extent and promote the formation of large molecules, particularly polymers.