Electronic Structure and Magnetic Anisotropy of an Unsaturated Cyclopentadienyl Iron(I) Complex with 15 Valence Electrons

Uttam Chakraborty; Serhiy Demeshko; Franc Meyer; Christophe Rebreyend; Bas de Bruin; Mihail Atanasov; Frank Neese; Bernd Mühldorf; Robert Wolf

doi:10.1002/anie.201702454

Electronic Structure and Magnetic Anisotropy of an Unsaturated Cyclopentadienyl Iron(I) Complex with 15 Valence Electrons

Angew Chem Int Ed Engl. 2017 Jun 26;56(27):7995-7999. doi: 10.1002/anie.201702454. Epub 2017 May 30.

Authors

Uttam Chakraborty¹, Serhiy Demeshko², Franc Meyer², Christophe Rebreyend³, Bas de Bruin³, Mihail Atanasov⁴, Frank Neese⁴, Bernd Mühldorf¹, Robert Wolf¹

Affiliations

¹ Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany.
² Institute of Inorganic Chemistry, University of Goettingen, 37077, Göttingen, Germany.
³ Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
⁴ Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.

PMID: 28557184
DOI: 10.1002/anie.201702454

Abstract

The 15 valence-electron iron(I) complex [Cp^Ar Fe(IiPr₂ Me₂ )] (1, Cp^Ar =C₅ (C₆ H₄ -4-Et)₅ ; IiPr₂ Me₂ =1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene) was synthesized in high yield from the Fe^II precursor [Cp^Ar Fe(μ-Br)]₂ . ⁵⁷ Fe Mössbauer and EPR spectroscopic data, magnetic measurements, and ab initio ligand-field calculations indicate an S= 3/2 ground state with a large negative zero-field splitting. As a consequence, 1 features magnetic anisotropy with an effective spin-reversal barrier of U_eff =64 cm^-1 . Moreover, 1 catalyzes the dehydrogenation of N,N-dimethylamine-borane, affording tetramethyl-1,3-diaza-2,4-diboretane under mild conditions.

Keywords: carbene ligands; cyclopentadienyl ligands; homogeneous catalysis; iron; magnetic properties.

Publication types

Research Support, Non-U.S. Gov't