Related Experiment Video
Updated: May 22, 2026

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
IR and IR + UV spectroscopy of isolated [Al-AcPheOMe]n+ cluster cations (n = 1, 3)
P M Bialach1, T C Martin, M Gerhards
1TU Kaiserslautern, Fachbereich Chemie & Research Center Optimas, Erwin-Schroedinger-Strasse 52, D-67663 Kaiserslautern, Germany.
Abstract:
Singly and triply charged cationic clusters of aluminium and the protected amino acid AcPheOMe are investigated in a supersonic beam by using a combination of a thermic and a laser ablation ion source. For the singly charged species UV- and IR photodissociation spectroscopy is applied. In the case of the triply charged clusters a variant of combined IR + UV spectroscopy is used to obtain information in the NH-stretching region. By comparison with DFT calculations structural assignments are suggested and it turns out that both clusters prefer a helical arrangement with aluminium being aggregated to both carbonyl groups. For the triply charged cluster a globular structure is formed in which aluminium is captured both by the carbonyl groups and the phenyl ring.
More Related Videos
Related Concept Videos
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
IR and UV–Vis Spectroscopy of Carboxylic Acids
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency, 1710 cm−1. The C=O bond of the...
IR Absorption Frequency: Hybridization
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
IR Frequency Region: Alkyne and Nitrile Stretching
Comparing the stretching vibrational frequency of C≡C triple bonds with that of double and single bonds, it is evident that C≡C triple bonds exhibit a higher stretching frequency than C=C double and C–C single bonds. Similarly, the C≡N triple bond exhibits higher stretching absorption than the C=N...
UV–Vis Spectroscopy: Molecular Electronic Transitions
NMR Spectroscopy and Mass Spectrometry of Aldehydes and Ketones

