Thermochemical ladders: Scaling the ramparts of gaseous ion energetics

The use of multiple overlapping gaseous ion-molecule equilibrium measuremen ts to construct thermochemical ladders is reviewed. The types of relative t hermochemical data, which may be obtained, are summarized and the types of measurements required to convert the relative equilibrium affinity scales t o absolute thermochemical quantities are discussed. The important thermoche mical scales produced include proton affinities, gas phase acidities, ioniz ation energies, electron affinities, carbocation stabilities, hydrogen bond energies, Lewis acidities, and metal cation affinities. (C) 2000 Elsevier Science B.V.