Facile Access to Mono- and Dinuclear Heteroleptic N-Heterocyclic Silylene Copper Complexes

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• 作者：Gengwen Tan ; Burgert Blom ; Daniel Gallego ; Matthias Driess
• 刊名：Organometallics
• 出版年：2014
• 出版时间：January 13, 2014
• 年：2014
• 卷：33
• 期：1
• 页码：363-369
• 全文大小：344K
• ISSN：1520-6041

文摘

Reaction of the heteroleptic N-heterocyclic chlorosilylene L(Cl)Si: (1; L = PhC(NtBu)₂) with [Cu(tmeda)(CH₃CN)][OTf] (2; tmeda = N,N,N鈥?N鈥?tetramethylethylenediamine, OTf = OSO₂CF₃ (triflate)) affords the Cu(I) complex [L(Cl)Si:鈫扖u(tmeda)][OTf] (3) in high yield as the first example of a heteroleptic N-heterocyclic silylene copper complex. Similarly, the reaction of L(OtBu)Si: (4; L = PhC(NtBu)₂) with 2 affords [L(OtBu)Si: 鈫?Cu(tmeda)][OTf] (5) and that of L(NMe₂)Si: (6) with 2 leads to [L(NMe₂)Si:鈫扖u(tmeda)][OTf] (7). Complex 3 shows a rather strong interaction in the solid state between the O atom of the triflate anion and the three-coordinate Cu(I) center with a Cu路路路O distance of 2.312 脜. In contrast, complex 7 features only a weak interaction (ca. 3.28 脜), while in complex 5 the cation and anion are fully separated. Strikingly, the reaction of the chelating oxo-bridged silylene :Si(L)(渭₂-O)(L)Si: (8) with the copper source [Cu(CH₃CN)₄][OTf] (9) affords the dinuclear complex salt [Cu₂{畏¹:畏¹-LSi(渭₂-O)SiL}₂][OTf]₂ (10), featuring a novel metallacyclooctane dication, selectively in a good yield. Complex 10 also exhibits a very strong interaction between the copper centers in the dication and the oxygen atoms of triflate anions in the solid state, evidenced by a Cu路路路O separation of only 2.141 脜. All complexes were fully characterized.