ELECTRON-AFFINITIES OF NAPHTHALENE, ANTHRACENE AND SUBSTITUTED NAPHTHALENES AND ANTHRACENES

The determination of electron transfer equilibria A- + B = A + B- in the gas phase, with a pulsed-electron high-pressure mass spectrometer, leads to DELTAG1-degrees, DELTAH-1-degrees, and DELTAS1-degrees values. These can be converted into the free energy, enthalpy and entropy changes, DELTAG(a)-degrees-(B), DELTAH(a)-degrees-(B) and DELTAS(a)-degrees-(B), for the reaction e + B = B-, since the corresponding values for the reference compounds A are known. Results were obtained for 18 substituted naphthalenes, anthracene and substituted anthracenes. The results are compared with some theoretical predictions and the corresponding reduction potentials in solution. Rate constants for 13 exoergic electron-transfer reactions were also measured. These were found to be close to the ADO collision rates.