title: Synthesis and NMR-study of 1-trimethylsilyl substituted silole anion [Ph₄C₄Si(SiMe₃)]⁻•[Li]⁺ and 3-silolenide 2,5-carbodianions {[Ph₄C₄Si(n-Bu)₂]⁻²•2[Li]⁺, [Ph₄C₄Si(t-Bu)₂]⁻²•2[Li]⁺} via silole dianion [Ph₄C₄Si]⁻²•2[Li]⁺.
abstract: 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.
authors.affiliation: Department of Nanopolymer Material Engineering, Pai Chai University, 155-40 Baejae-ro-Doma-Dong, Seo-Gu, Daejon 302-735, Korea. jhong@pcu.ac.kr
authors.forename: Jang-Hwan
authors.initials: JH
authors.lastname: Hong
mesh_terms: D000838:Anions / Q000138:chemical synthesis; D018360:Crystallography, X-Ray; D006842:Hydrocarbons, Brominated / Q000737:chemistry; D006847:Hydrocarbons, Iodinated / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D012821:Silanes / Q000138:chemical synthesis*; D013010:Sonication
chemical_list: D000838:Anions; D006842:Hydrocarbons, Brominated; D006847:Hydrocarbons, Iodinated; D012821:Silanes; D008094:Lithium; C014055:methyl iodide; C047757:butyl bromide