30 May 2017

Magneto-structural correlations in a transition metal complex

Representative high-field EPR data and structural details of the (PPh4)2[Co(SPh)4] molecule. Representative high-field EPR data and structural details of the (PPh4)2[Co(SPh)4] molecule.

In the field of inorganic chemistry, magneto-structural correlations have been used to rationally design molecules with desirable properties, and to relate these properties to the electronic and geometric structures. In turn, such studies provide powerful tools for understanding important catalytic processes, as well as elucidating the structures of active sites in metalloproteins. This study reveals an unusually strong sensitivity of the magnetic properties of a CoS4 molecule to minute changes in its structure.

What did scientists discover?

Studies of two related cobalt-II complexes reveal a surprisingly strong dependence of the axial anisotropy, 2D, on geometric angles in the cluster, specifically the S−Co−S angle, θ, and the C−S−Co−S torsion angle, ψ, around the CoS4 core. Indeed, not only does the magnitude of the zero-field-splitting parameter, 2D, change significantly, its sign changes as well, i.e., the anisotropy switches from easy-axis to easy-plane.

Why is this important?

Understanding magneto-structural correlations (the relationship between molecular structure and magnetic properties) is a critical step toward the rational design of molecules with desirable magnetic properties. In turn, such studies can provide powerful tools for understanding important catalytic processes, as well as elucidating the structures of active sites in metallo-proteins.

Who did the research?

E. A. Suturina1,2, J. Nehrkorn3, J. M. Zadrozny4,5, J. Liu5,6, M. Atanasov1,6, T. Weyhermüller1, D. Maganas1, S. Hill5, A. Schnegg3, E. Bill1, J. R. Long4, F. Neese1

1Max Planck Institute for Chemical Energy Conversion; 2Novosibirsk State University; 3Helmholtz-Zentrum Berlin; 4UC Berkeley; 5Northwestern; 5National MagLab; 6University of Oxford; 6Bulgarian Academy of Sciences

Why did they need the MagLab?

THE TOOLS THEY USED

This research was conducted in the 35 Tesla, 32 mm Bore Magnet in the DC Field Facility.

Electron Paramagnetic Resonance (EPR) provides a direct measure of magnetic anisotropy and is, therefore, the method of choice to verify theoretical predictions. However, giant anisotropies require very high frequencies and/or giant magnetic fields. For this reason, the EPR measurements had to be performed at the MagLab.

Details for scientists

Funding

This research was funded by the following grants: G.S. Boebinger (NSF DMR-1157490); J.R. Long (NSF CHE-1464841); E.A. Suturina (Russian Science Foundation); A. Schnegg (DFG)


For more information, contact Stephen Hill.

Details

  • Research Area: Biochemistry, Chemistry, Magnetism and Magnetic Materials
  • Research Initiatives: Energy, Life,Materials
  • Facility / Program: EMR
  • Year: 2017
Last modified on 2 June 2017