The site of Cr+ attachment to gas-phase aniline from infrared spectroscopy
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Updated: Jul 23, 2026

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores
Published on: August 19, 2013
Jos Oomens1, David T Moore, Gert Von Helden
1FOM Institute for Plasma Physics "Rijnhuizen", Postbus 1207, 3430 BE Nieuwegein, The Netherlands.
Abstract:
Infrared spectroscopy of gas-phase Cr+ complexes of aniline was studied using the FELIX free electron laser interfaced to a Fourier transform ion cyclotron resonance spectrometer. For both the monomer complex Cr+(aniline) and the dimer complex Cr+(aniline)2 the spectra showed features indicating binding of the metal ion to the aromatic pi cloud, as opposed to the nitrogen atom. Agreement with DFT-calculated infrared absorption spectra for the ring-bound complexes was good using the MPW1PW91 functional, but the B3LYP functional predicted the wrong binding site. The spectroscopic results resolve the ambiguity in computational prediction of the preferred binding site and support the use of the MPW1PW91 functional for these systems.
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