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

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• 作者：Johannes A. Baus ; Dr. Felix M. M&uuml ; ck ; Heidi Schneider and Prof. Dr. Reinhold Tacke
• 刊名：Chemistry - A European Journal
• 出版年：2017
• 出版时间：January 5, 2017
• 年：2017
• 卷：23
• 期：2
• 页码：296-303
• 全文大小：1923K
• ISSN：1521-3765

文摘

Reaction of the donor-stabilized silylene [iPrNC(NiPr₂)NiPr]₂Si (1) with FeBr₂, CoBr₂, NiBr₂⋅MeOCH₂CH₂OMe, ZnCl₂, and ZnBr₂ afforded 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 by ¹⁵N and ²⁹Si 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 Fe^II, Co^II, Ni^II, and Zn^II silylene 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.