3 METHODS TO MEASURE RH BOND-ENERGIES

We present a critical review of three different experimental methods u sed to measure bond energies: radical kinetics, gas-phase acidity cycl es, and photoionization mass spectrometry. These experimental techniqu es are currently in use to measure the bond energies of a large number of molecules. We discuss the basic premises of each of these experime nts and explicitly try to point out the strengths and weaknesses of ea ch method. We directly compare each of these procedures using a set of about 30 important molecules. These three different techniques have o nly a few disagreements among them, the case of ethylene being the mos t serious. For the overwhelming number of studies, all measurements le ad to bond energies within each other's error bars. We include tables of ionization potentials, electron affinities, and heats of formation for about 40 important organic and inorganic radicals. We also list bo nd energies for the parent molecules at 0 and 298 K.