We have measured the gas-phase electron affinities of indenyl and fluorenyl radicals to be 42.7 +/- 0.3 and 43.1 +/- 0.3 kcal/mol, respectively, by electron photodetachment spectroscopy, using an ion cyclotron resonance spectrometer to generate, trap, and detect ions. From the electron affinities and literature values for the gas-phase acidities, we derive the bond dissociation energies : indene, 81.1 +/- 2.4 kcal/mol and fluorene, 81.3 +/- 2.4 kcal/mol. We describe a general approach for comparing gas and solution-phase ionic properties.