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Rational Design of a Confacial Pentaoctahedron: Anisotropic Exchange in a Linear Zn II Fe III Fe III Fe III Zn II Complex
Author(s) -
Walleck Stephan,
Atanasov Mihail,
Schnack Jürgen,
Bill Eckhard,
Stammler Anja,
Bögge Hartmut,
Glaser Thorsten
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202102572
Subject(s) - crystallography , zeeman effect , chemistry , ferromagnetism , ab initio , metal , ab initio quantum chemistry methods , spectral line , analytical chemistry (journal) , atomic physics , physics , magnetic field , condensed matter physics , molecule , quantum mechanics , organic chemistry , chromatography
The first confacial pentaoctahedron comprised of transition metal ions namely Zn II Fe III A Fe III B Fe III A Zn II has been synthesized by using a dinucleating nonadentate ligand. The face‐sharing bridging mode enforces short Zn II ⋅⋅⋅Fe III A and Fe III A ⋅⋅⋅Fe III B distances of 2.83 and 2.72 Å, respectively. Ab‐initio CASSCF/NEVPT2 calculations provide significant negative zero‐field splittings for Fe III A and Fe III B with | D A |>| D B | with the main component along the C 3 axis. Hence, a spin‐Hamiltonian comprised of anisotropic exchange, zero‐field, and Zeeman term was employed. This allowed by following the boundary conditions from the theoretical results the simulation in a theory‐guided parameter determination with J xy =+0.37, J z =−0.32, D A =−1.21, E A =−0.24, D B =−0.35, and E B =−0.01 cm −1 supported by simulations of high‐field magnetic Mössbauer spectra recorded at 2 K. The weak but ferromagnetic Fe III A Fe III B interaction arises from the small bridging angle of 84.8° being at the switch from anti‐ to ferromagnetic for the face‐sharing bridging mode.