Related Experiment Video
Updated: May 12, 2026

Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyl(tropone)iron
Published on: August 12, 2019
1,3-Diketone fluids and their complexes with iron
Michael Walter1, Tobias Amann, Ke Li
1FMF, Freiburg Materials Research Center, University of Freiburg, Stefan-Meier-Straße 21, 79104 Freiburg, Germany. Michael.Walter@fmf.uni-freiburg.de
Abstract:
Tribological experiments with 1,3-diketone fluids in contact with iron surfaces show ultralow friction, which was suggested to be connected to the formation of iron complexes. In order to support this assumption, we calculate infrared and optical spectra of various substituted 1,3-diketones and their iron complexes using gradient-corrected density functional theory (DFT). The description of the complexes requires the application of the DFT+U scheme for a correct prediction of the high spin state on the central iron atom. With this approach, we obtain excellent agreement between experiment and simulation in infrared and optical spectra, allowing for the determination of 1,3-diketone tautomeric forms. The match in the spectra of the complex strongly supports the assumption of iron complex formation by these lubricants.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Formation of Complex Ions
Complexation Equilibria: Factors Influencing Stability of Complexes
Complexometric Titration: Ligands
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Complexation Equilibria: The Chelate Effect

