N−H and N=C Bond Formation via Germanium(III) Diradicaloid Intermediates and C−S Bond Cleavage in Reactions of the Digermyne Ar′GeGeAr′ (Ar′ = C6H3-

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• 作者：Xinping Wang ; Chengbao Ni ; Zhongliang Zhu ; James C. Fettinger ; Philip P. Power*
• 刊名：Inorganic Chemistry
• 出版年：2009
• 出版时间：March 16, 2009
• 年：2009
• 卷：48
• 期：6
• 页码：2464-2470
• 全文大小：265K
• 年卷期：v.48,no.6(March 16, 2009)
• ISSN：1520-510X

文摘

Reactions of the digermyne Ar′GeGeAr′ (Ar′ = C₆H₃-2,6(C₆H₃-2,6-Prⁱ₂)₂) (1) with four different azides R′N₃ (R = Me₃Sn, ⁿBu₃Sn, PhSCH₂, or 1-adamantanyl) are described. Treatment of 1 with Me₃SnN₃ or ⁿBu₃SnN₃ afforded the low-valent germanium (II) parent amido derivative, Ar′Ge(μ₂-NH₂)₂GeAr′ (3) or the high-valent germanium (IV) parent imido derivative, Ar′(ⁿBu₃Sn)Ge(μ₂-NH)₂Ge(SnⁿBu₃)Ar′ (4), respectively. Addition of AdN₃ (Ad =1-admantanyl) yielded a monoimide bridged species Ar′Ge(μ₂-NAd)GeAr′ (5). The structure of 5 differs from that of the diradicaloid Ar′Ge(μ₂-NSiMe₃)₂GeAr′ (2), which was previously obtained from the analogous reaction of 1 with Me₃SiN₃. The reaction of 1 with PhSCH₂N₃ afforded the germanium ketimide Ar′Ge(SPh)₂(N=CH₂) (6) containing the imino −N=CH₂ functional group. These reactions demonstrate a remarkable product dependence on the azide substituent. All compounds were spectroscopically and structurally characterized. Both 3 and 4 feature a four-membered Ge₂N₂ core. The structure of 5 is stabilized by CH-π interactions while 6 features a rare example of a π-π interaction between an aromatic ring and a non-aromatic double bond (N=C). The mechanism of formation of 3−6 are discussed. It is proposed that 3 and 4 are obtained via diradical imido intermediates followed by H-abstraction from solvents, whereas 6 was formed by the activation of azide group in concert with C−S bond cleavage.