Unexpected Disproportionation of Tetramethylethylenediamine-Supported Perchlorodisilane Cl3SiSiCl3

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• 作者：Jan Tillmann ; Frank Meyer-Wegner ; Andor Nadj ; Johanna Becker-Baldus ; Tanja Sinke ; Michael Bolte ; Max C. Holthausen ; Matthias Wagner ; Hans-Wolfram Lerner
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：August 6, 2012
• 年：2012
• 卷：51
• 期：15
• 页码：8599-8606
• 全文大小：471K
• 年卷期：v.51,no.15(August 6, 2012)
• ISSN：1520-510X

文摘

The addition compound Cl₃SiSiCl₃路TMEDA was formed quantitatively by treatment of Cl₃SiSiCl₃ with tetramethylethylenediamine (TMEDA) in pentane at room temperature. The crystal structure of Cl₃SiSiCl₃路TMEDA displays one tetrahedrally and one octahedrally bonded Si atom (monoclinic, P2₁/n). ²⁹Si CP/MAS NMR spectroscopy confirms this structure. Density functional theory (DFT) calculations have shown that the structure of the meridional isomer of Cl₃SiSiCl₃路TMEDA is 6.3 kcal lower in energy than that of facial coordinate species. Dissolving of Cl₃SiSiCl₃路TMEDA in CH₂Cl₂ resulted in an immediate reaction by which oligochlorosilanes Si_nCl_2n (n = 4, 6, 8, 10; precipitate) and the Cl^{鈥?/sup>-complexed dianions [Si_nCl_2n+2]2鈥?/sup> (n = 6, 8, 10, 12; CH₂Cl₂ extract) were formed. The constitutions of these compounds were confirmed by MALDI mass spectrometry. Additionally, single crystals of [Me₃NCH₂CH₂NMe₂]₂[Si₆Cl₁₄] and [Me₃NCH₂CH₂NMe₂]₂[Si₈Cl₁₈] were obtained from the CH₂Cl₂ extract. We found that Cl₃SiSiCl₃路TMEDA reacts with MeCl, forming MeSiCl₃ and the products that had been formed in the reaction of Cl₃SiSiCl₃路TMEDA with CH₂Cl₂. X-ray structure analysis indicates that the structures of [Me₃NCH₂CH₂NMe₂]₂[Si₆Cl₁₄] (monoclinic, P2₁/n) and [Me₃NCH₂CH₂NMe₂]₂[Si₈Cl₁₈] (monoclinic, P2₁/n) contain dianions adopting an 鈥渋nverse sandwich鈥?structure with inverse polarity and [Me₃NCH₂CH₂NMe₂]+ as countercations. Single crystals of SiCl₄路TMEDA (monoclinic, Cc) could be isolated by thermolysis reaction of Cl₃SiSiCl₃路TMEDA (50 掳C) in tetrahydrofuran (THF).}