Some recent aspects of unimolecular gas phase ion chemistry

Unimolecular reactions in the gas phase have been known for nearly a century. Unimolecular ionic reactions form the basis for mass spectrometry. This review article covers three major aspects: (1) Activation of unimolecular reactions by ambient blackbody radiation and the resultant work on biomolecules. (2) The definition of activated complex parameters through RRKM calculations on ab initio potential energy surfaces. (3) Competing decay mechanisms of large hot carbon cluster ions—radiative decay and thermionic emission.