title: Iron(II), Cobalt(II), Nickel(II), and Zinc(II) Silylene Complexes: Reaction of the Silylene [iPrNC(NiPr2)NiPr]2Si with FeBr2, CoBr2, NiBr2⋅MeOCH2CH2OMe, ZnCl2, and ZnBr2.
abstract: Reaction of the donor-stabilized silylene [iPrNC(NiPr2)NiPr]2Si (1) with FeBr2, CoBr2, NiBr2⋅MeOCH2CH2OMe, ZnCl2, and ZnBr2afforded the respective transition-metal silylene complexes 4-8, the formation of which can be described in terms of a Lewis acid/base reaction (4, 5, 7, 8) or a nucleophilic substitution reaction (6). However, the reactivity profile of silylene 1 is not only based on its strong Lewis base character; the different coordination modes of the two guanidinato ligands (4-6 vs. 7 and 8) add an additional reactivity facet. The paramagnetic compounds 4 and 5 and the diamagnetic compounds 6⋅THF, 7, and 8⋅0.5 Et2O were structurally characterized by single-crystal X-ray diffraction. In addition, compound 6⋅THF was studied by15N and29Si solid-state NMR spectroscopy, and 7 and 8 were characterized by NMR spectroscopic studies in the solid state (15N,29Si) and in solution (1H,13C,29Si). Compounds 4-8 represent very rare examples of FeII, CoII, NiII, and ZnIIsilylene complexes. Four-coordinate silicon(II) compounds with an SiN3M skeleton (M=Fe, Co, Ni) and M in the formal oxidation state +2 (4-6) have not yet been reported, and five-coordinate silicon(II) compounds with an SiN4Zn skeleton (7, 8) are also unprecedented.
authors.affiliation: Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Baus
authors.affiliation: Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Felix M
authors.initials: FM
authors.lastname: Mück
authors.affiliation: Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Heidi
authors.initials: H
authors.lastname: Schneider
authors.affiliation: Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074, Würzburg, Germany.
authors.forename: Reinhold
authors.identifier: 0000-0003-4532-2647
authors.initials: R
authors.lastname: Tacke
keywords: Lewis acid/base reactions; guanidinato ligands; silicon; silylenes; transition-metal complexes