Related Experiment Video
Updated: Apr 15, 2026

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Proton transfer and isotope-induced reaction in aniline cluster ions
Jozef Lengyel1, Viktoriya Poterya, Michal Fárník
1J. Heyrovský Institute of Physical Chemistry v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 18223, Prague, Czech Republic; Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, 16628, Prague, Czech Republic.
Abstract:
The proton transfer (PT) and other intraclusters reactions occurring after electron ionization of aniline clusters (PhNH2)N are investigated by the time-of-flight mass spectrometry. The mass spectra are recorded for different expansion conditions leading to the generation of different cluster sizes. Several fragment ions are shown to originate from intracluster reactions, namely, [Ph](+), [PhNH3](+) and [Ph-N-Ph](+). Reaction schemes are proposed for these ions starting with the PT process. The mass region beyond the monomer mass is dominated by cluster ions (PhNH2)n(+) accompanied by satellites with ±H and +2H. In experiments with deuterated species, new fragment ions are identified. The aniline isotopomer d5-PhNH2 yields the fragment ions (PhNH2)n⋅(N-Ph-NH2)(+). Analogical series is observed in experiments with d7-PhND2, and additional fragments occur corresponding to (PhND2)n⋅(D2N-ND-Ph-ND-ND2)(+) ions. The possible reaction pathways to these ions and the unusual isotope effects are discussed.
Related Concept Videos
Mass Spectrometry of Amines
NMR Spectroscopy Of Amines
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
Diazonium Group Substitution: –OH and –H
Mass Spectrometry: Amine Fragmentation
In amines, the number of nitrogen atoms affects the mass of the molecular ion, which is described by the nitrogen rule of mass spectrometry. This rule states that a compound containing...
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...

