Abstract
Structure and unimolecular reactivity of protonated para-aminophenol generated by the electrospray ionization were studied by means of mass spectrometry, IRMPD spectroscopy and DFT calculation. It is revealed that protonation of para-aminophenol takes place at the nitrogen atom.
Under the conditions of the IRMPD experiment, thermodynamically favored elimination of the water molecule is observed, whereas under the CID experiment kinetically favored elimination of ammonia prevails. The IRMPD spectrum as well as all fragmentation pathways are rationalized based on DFT calculations.