Synthetic, Structural, and Physical Investigations of the Large Linear and Branched Oligogermanes Ph3GeGePh2GePh2GePh2H, Ge5Ph12, and

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• 作者：Christian R. Samanamu ; Monika L. Amadoruge ; Aaron C. Schrick ; Chao Chen ; James A. Golen ; Arnold L. Rheingold ; Nicholas F. Materer ; Charles S. Weinert
• 刊名：Organometallics
• 出版年：2012
• 出版时间：June 11, 2012
• 年：2012
• 卷：31
• 期：11
• 页码：4374-4385
• 全文大小：552K
• 年卷期：v.31,no.11(June 11, 2012)
• ISSN：1520-6041

文摘

The syntheses of two linear oligogermanes, Ph₃GeGePh₂GePh₂GePh₂H and Ge₅Ph₁₂, were achieved using a hydrogermolysis reaction starting with HPh₂GeGePh₂GePh₂H. The preparation of the hydride-terminated tetragermane indicates that selectivity is possible using the hydrogermolysis reaction, which had not been observed previously. The structures of both of these compounds were determined, and they were also characterized by UV/visible spectroscopy and electrochemical methods (CV and DPV). The pentagermane Ge₅Ph₁₂ exhibits four irreversible oxidation waves in both its CV and DPV, as was observed for other aryl-substituted oligogermanes. The successful synthesis of the neopentane analogue (Ph₃Ge)₄Ge was also achieved by starting from GeH₄ and Ph₃GeCH₂CN. This material was structurally characterized; the structure of (Ph₃Ge)₄Ge is highly sterically congested and contains long Ge鈥揋e single-bond distances that average 2.497(6) 脜 and exhibits an nearly idealized tetrahedral geometry at the central germanium atom with an average Ge鈥揋e鈥揋e bond angle of 109.49(2)掳. The UV/visible spectrum of (Ph₃Ge)₄Ge exhibits a broad absorbance maximum centered at 250 nm, and DFT calculations indicate that this compound has a stabilized HOMO at 鈭?.223 eV and a large HOMO鈥揕UMO gap relative to those in other branched oligogermanes.