Iron(II), Cobalt(II), Nickel(II), and Zinc(II) Silylene Complexes: Reaction of the Silylene [iPrNC(NiPrb>2b>)NiPr]b>2b>Si with FeBrb>2b>, CoBrb>2b>, NiBrb>2b>⋅MeOCHb>2b>CHb>2b>OMe, ZnClb>2b>, and ZnBrb>2b>

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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(NiPrb>2b>)NiPr]b>2b>Si (<b>1b>) with FeBrb>2b>, CoBrb>2b>, NiBrb>2b>&sdot;MeOCHb>2b>CHb>2b>OMe, ZnClb>2b>, and ZnBrb>2b> afforded the respective transition-metal silylene complexes <b>4b>–<b>8b>, the formation of which can be described in terms of a Lewis acid/base reaction (<b>4b>, <b>5b>, <b>7b>, <b>8b>) or a nucleophilic substitution reaction (<b>6b>). However, the reactivity profile of silylene <b>1b> is not only based on its strong Lewis base character; the different coordination modes of the two guanidinato ligands (<b>4b>–<b>6b> vs. <b>7b> and <b>8b>) add an additional reactivity facet. The paramagnetic compounds <b>4b> and <b>5b> and the diamagnetic compounds <b>6b>&sdot;THF, <b>7b>, and <b>8b>&sdot;0.5 Etb>2b>O were structurally characterized by single-crystal X-ray diffraction. In addition, compound <b>6b>&sdot;THF was studied by ¹⁵N and ²⁹Si solid-state NMR spectroscopy, and <b>7b> and <b>8b> were characterized by NMR spectroscopic studies in the solid state (¹⁵N, ²⁹Si) and in solution (¹H, ¹³C, ²⁹Si). Compounds <b>4b>–<b>8b> represent very rare examples of Fe^II, Co^II, Ni^II, and Zn^II silylene complexes. Four-coordinate silicon(II) compounds with an SiNb>3b>M skeleton (M=Fe, Co, Ni) and M in the formal oxidation state +2 (<b>4b>–<b>6b>) have not yet been reported, and five-coordinate silicon(II) compounds with an SiNb>4b>Zn skeleton (<b>7b>, <b>8b>) are also unprecedented.