METASTABLE DECAY OF PROPANE (CH3CD2CH3)-CLUSER AND ARGON PROPANE-CLUSTER IONS INDUCED BY ISOMERIZATION OF A PROPYL ION CORE AND FRAGMENTATION PATTERNS OF PROPANE IONS IN THE CLUSTER ENVIRONMENT/

Metastable decay processes occurring in neat propane and argon/propane cluster ions with a propyl ion core have been further investigated us ing partially deuterated propane, CH3CD2CH3. It is concluded that the previously described metastable decay channel leading to the evaporati on of up to four monomers is induced by isomerization of the corner-pr otonated cyclopropane ion to the 2-propyl cation via a transient 1-pro pyl ion. A considerable decrease of the relative abundance of fragment ions upon electron impact ionization is observed when going from the monomer propane to the cluster environment (C3H8 or Ar). This suppress ion of the unimolecular decay of the clustered propane ions may be rat ionalized by energy transfer from the ion to the surrounding cluster e nvironment and by cage recombination processes of the dissociating fra gments.