ON THE RELEASE OF TRANSLATIONAL ENERGY WHEN STABLE INTERMEDIATE ION-NEUTRAL COMPLEXES DISSOCIATE

The loss of alkane molecules from metastable aliphatic alcohol and eth er radical cations in the gas phase can be used to probe the propertie s of intermediate weakly bonded ion-neutral complexes. Very little tra nslational energy is released when the final products form a stable co mplex prior to dissociation, whereas the energy released can directly reflect the heat of reaction when dissociation takes place subsequent to an exothermic intra-complex reaction. The heats of formation of the intermediate oxonium ions and the product radical cations of enols an d enol ethers were determined using the composite G2(MP2) and CBS-Q hi gh-level ab initio methods. (C) 1997 Elsevier Science B.V.