English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Supersilylsilanes R*SiX 3  (R* = supersilyl = SitBu 3 ; X = H, Me, tBu, Ph, SiMe 3 , F, Cl, Br, I, OMe, OSO 2 CF 3 ) are prepared (i) by reactions of supersilylhalosilanes with supersilyl sodium NaR* (Hal/R* exchange), (ii) by reactions of supersilylhalosilanes with hydride H -  (Hal/H exchange), (iii) by reactions of supersilylsilanes with halogens Hal 2  (H/Hal exchange, R*/Hal exchange), (iv) by reactions of supersilylhalosilanes with nucleophiles like F -  , MeO -  (Hal/F or Hal/OMe exchange) and (v) by reactions of supersilylsilanes with strong acids (H/OSO 2 CF 3  exchange). NMR chemical shifts δ ( 29 Si) of the SiX 3  groups of R*SiX 3  strongly depends on the nature of X. The supersilylsilanes R*SiX 3  are in part moisture sensitive (especially compounds with SiX 3 ≡SiHHal 2  and SiH 2 Hal), in part sensitive against oxygen (compounds with SiX≡SiBr or SiI), and some of them react with supersilyl sodium by supersilanidation (for example R*SiF 3 , R*SiH 2 Cl, R*SiMeHCl) or by reduction (for example R*SiCl 3 , R*SiMeBr 2 , R*SiPhBrCl). X-ray structure analyses of disilanes tBu 3 Si-SiX 3  with SiX 3 ≡SitBu 3 , SiPh 3 , Sil 3 , SiPhCl 2  show a staggered conformation. Due to steric repulsion of the tBu 3 Si and SiX 3  groups as well as van-der-Waals attraction of the substituents tBu and X in tBu 3 Si-SiX 3  the SiSi bonds are longer than 2.34 Å (the normal SiSi single bond length) and the torsion angles are smaller/larger than 60° (the ideal staggered conformation). From the extent of SiSi bond elongation and CSiSiX angle compression it is concluded that the bulkiness of X increases in direction Cl &lt; I &lt; Ph &lt; SiMe 3  &lt; CMe 3  (tBu 3 Si-SitBu 3  has to date the longest SiSi bond of all disilanes) and the van-der-Waals forces between tBu/X increase in direction tBu/I &lt; tBu/tBu &lt; tBu/Ph.

zeitschrift für naturforschung b

Supersilylsilane R*SiX 3 : Darstellung, Charakterisierung und Strukturen; sterische und van-der-Waals Effekte der Substituenten X [1] / Supersilylsilanes R*SiX 3 : Syntheses, Characterization and Structures; Steric and van-der-Waals Effects of Substituents X [1]