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Intramolecular Antiferromagnetism in μ‐Oxo‐bis[(5,15‐dimethyl‐2,3,7,8,12,13,17,18‐octaethylporphyrinato)iron(III)]
Author(s) -
Lueken Heiko,
Handrick Klaus,
Schilder Helmut,
Buchler Johann W.,
Lay KiongLam
Publication year - 1996
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.19966220114
Subject(s) - antiferromagnetism , intramolecular force , chemistry , magnetism , hamiltonian (control theory) , isotropy , exchange interaction , heisenberg model , spin (aerodynamics) , crystallography , ferromagnetism , condensed matter physics , computational chemistry , stereochemistry , physics , thermodynamics , quantum mechanics , mathematical optimization , mathematics
The magnetism of μ‐oxo‐bis[(5,15‐dimethyl‐2,3,7,8,12,13,17,18‐octaethylporphyrinato)iron(III)] with bridge geometry d(FeO) = 1.752 Å and ∢(FeOFe) = 178.6° can be explained in terms of antiferromagnetically exchange coupled iron(III)‐3d 5 pairs. The magnetochemical analysis in the temperature range 6K–295K on the basis of the isotropic Heisenberg model (spin Hamiltonian: Ĥ = −2 J Ŝ 1 · Ŝ 2 S 1 = S 2 = 5/2) leads to the exchange parameter J = −125 cm −1 . With regard to the FeO bond length the J value corresponds to the series of data observed for other μ‐oxodiiron‐porphyrins and ‐porphycenes. Compared to the spin‐spin coupling in [Fe 2 Cl 6 O] 2− , | J | is enhanced by ≈ 10%.