Oligosilanylsilatranes
نویسندگان
چکیده
Oligosilanes with attached silatranyl units were obtained by reactions of potassium oligosilanides with a silatranyl triflate. Interaction between Si and N atoms was observed in the 29Si NMR spectra (upfield-shifted SiO3 resonances) and in the solid-state structures (Si-N distances between 2.29 and 2.16 Å). The Si-N interaction can be "switched off" either by protonation of the nitrogen lone pair or by potassium silanide formation caused by trimethylsilyl group cleavage in the presence of potassium tert-butoxide.
منابع مشابه
Electron Transfer and Modification of Oligosilanylsilatranes and Related Derivatives
Several silatranyl -substituted oligosilanes were prepared starting from bis(trimethylsilyl)silatranylsilanide. Electrochemical and theoretical investigations of some oligosilanes revealed that electrooxidation occurs by formation of a short-lived cation radical. This species undergoes structural relaxation to form a pair of conformers, with endo and exo relationships with respect to the Si-N i...
متن کاملTuning the Si–N Interaction in Metalated Oligosilanylsilatranes
Most known silatrane chemistry is concerned with examples where the attached silatrane substituent atom is that of an element more electronegative than silicon. The current study features silylated silatranes with a range of electropositive elements attached to the silyl group. The resulting compounds show different degrees of electron density on the silatrane-substituted silicon atom. This dir...
متن کاملGains from diversification on convex combinations: A majorization and stochastic dominance approach
By incorporating both majorization theory and stochastic dominance theory, this paper presents a general theory and a unifying framework for determining the diversification preferences of risk-averse investors and conditions under which they would unanimously judge a particular asset to be superior. In particular, we develop a theory for comparing the preferences of different convex combination...
متن کاملImproved immunogenicity of tetanus toxoid by Brucella abortus S19 LPS adjuvant.
BACKGROUND Adjuvants are used to increase the immunogenicity of new generation vaccines, especially those based on recombinant proteins. Despite immunostimulatory properties, the use of bacterial lipopolysaccharide (LPS) as an adjuvant has been hampered due to its toxicity and pyrogenicity. Brucella abortus LPS is less toxic and has no pyrogenic properties compared to LPS from other gram negati...
متن کاملSteady electrodiffusion in hydrogel-colloid composites: macroscale properties from microscale electrokinetics.
A rigorous microscale electrokinetic model for hydrogel-colloid composites is adopted to compute macroscale profiles of electrolyte concentration, electrostatic potential, and hydrostatic pressure across membranes that separate electrolytes with different concentrations. The membranes are uncharged polymeric hydrogels in which charged spherical colloidal particles are immobilized and randomly d...
متن کامل