Department of Nanopolymer Material Engineering, Pai Chai University, 155-40 Baejae-ro-Doma-Dong, Seo-Gu, Daejon 302-735, Korea.
Molecules. 2013 Aug 30;18(9):10568-79. doi: 10.3390/molecules180910568.
1-Trimethylsilyl, 1-R (R = Me, Et, i-Bu)-2,3,4,5-tetraphenyl-1-silacyclopentadiene [[Ph₄C₄Si(SiMe₃)]R] are synthesized from the reaction of 1-trimethylsilyl,1-lithio-2,3,4,5-tetraphenyl-1-silacyclopentadienide anion [[Ph₄C₄Si(SiMe₃]⁻•[Li]⁺ (3) with methyl iodide, ethyl iodide, and i-butyl bromide. The versatile intermediate 3 is prepared by hemisilylation of the silole dianion [Ph₄C₄Si]⁻²•2[Li]⁺ (2) with trimethylsilyl chloride and characterized by ¹H-, ¹³C-, and ²⁹Si-NMR spectroscopy. 1,1-bis(R)-2,3,4,5-tetraphenyl-1-silacyclopentadiene [Ph₄C₄SiR₂] {R = n-Bu (7); t-Bu (8)} are synthesized from the reaction of 2 with n-butyl bromide and t-butyl bromide. Reduction of 7 and 8 with lithium under sonication gives the respective 3-silolenide 2,5-carbodianions {[Ph₄C₄Si(n-Bu)₂]⁻²•2[Li]⁺ (10) and {[Ph₄C₄Si(t-Bu)₂]⁻²•2[Li]⁺ (11)}, which are characterized by ¹H-, ¹³C-, and ²⁹Si-NMR spectroscopy. Polarization of phenyl groups in 3 is compared with those of silole anion/dianion, germole anion/dianion, and 3-silolenide 2,5-carbodianions 10 and 11.
1-三甲基甲硅烷基,1-R(R = Me,Et,i-Bu)-2,3,4,5-四苯基-1-硅杂环戊二烯 [[Ph₄C₄Si(SiMe₃)]R] 是通过 1-三甲基甲硅烷基,1-锂-2,3,4,5-四苯基-1-硅杂环戊二烯阴离子 [[Ph₄C₄Si(SiMe₃]⁻•[Li]⁺(3)与甲基碘,乙基碘和碘代叔丁烷的反应合成的。多功能中间体 3 是通过硅杂环戊二烯二阴离子[Ph₄C₄Si]⁻²•2[Li]⁺(2)与三甲基甲硅烷基氯的半硅化反应制备的,并通过¹H-,¹³C-和²⁹Si-NMR 光谱进行了表征。1,1-双(R)-2,3,4,5-四苯基-1-硅杂环戊二烯[Ph₄C₄SiR₂] {R = n-Bu(7); t-Bu(8)} 是通过 2 与正丁基溴和叔丁基溴的反应合成的。超声处理下用锂还原 7 和 8 得到相应的 3-硅杂环戊二烯-2,5-二碳二阴离子{[Ph₄C₄Si(n-Bu)₂]⁻²•2[Li]⁺(10)和{[Ph₄C₄Si(t-Bu)₂]⁻²•2[Li]⁺(11)},通过¹H-,¹³C-和²⁹Si-NMR 光谱对其进行了表征。比较了 3 中苯基的极化与硅杂环戊二烯阴离子/二阴离子、锗杂环戊二烯阴离子/二阴离子以及 3-硅杂环戊二烯-2,5-二碳二阴离子 10 和 11 的极化。