Description:
AbstractThe 15 valence‐electron iron(I) complex [CpArFe(IiPr2Me2)] (1, CpAr=C5(C6H4‐4‐Et)5; IiPr2Me2=1,3‐diisopropyl‐4,5‐dimethylimidazolin‐2‐ylidene) was synthesized in high yield from the FeII precursor [CpArFe(μ‐Br)]2. 57Fe 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 Ueff=64 cm−1. Moreover, 1 catalyzes the dehydrogenation of N,N‐dimethylamine–borane, affording tetramethyl‐1,3‐diaza‐2,4‐diboretane under mild conditions.