This work examined the dissociation reactions and energetics of deprotonated nitrophenols. All species were generated using an atmospheric pressure chemical ionization source and were studied using tandem mass spectrometry. Collision induced dissociation studies revealed three common fragments: C6H4O center dot-, NO2-, and C6H4O2 center dot-. Energy dependent collision induced dissociation showed the formation of C6H4O center dot- by the loss of NO center dot is the lowest energy pathway for each isomer. The C-N dissociation energy to yield NO2- is large, and is due to the stability of the nitrophenoxide anion. (C) 2014 Elsevier B.V. All rights reserved.