Notizen: Silylierung mit Hexamethyldisilazan

Ismail, Roshdy M.

doi:10.1515/znb-1963-0717

Cited by 10 publications

(3 citation statements)

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“…4,4′-Bis(trimethylsiloxy)biphenyl 1 was synthesized according to a previously reported protocol [ 65 ]; the silylated product was additionally purified by crystallization from n -hexane. 2,6-Bis(trimethylsiloxy)naphthalene 2 was prepared analogously by silylation of the diol with hexamethyldisilazane (HMDS) using KOtBu as a catalyst.…”

Section: Resultsmentioning

confidence: 99%

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A Non-Hydrolytic Sol–Gel Route to Organic-Inorganic Hybrid Polymers: Linearly Expanded Silica and Silsesquioxanes

Krupinski

Wagler

Brendler

et al. 2023

Gels

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Condensation reactions of chlorosilanes (SiCl4 and CH3SiCl3) and bis(trimethylsilyl)ethers of rigid, quasi-linear diols (CH3)3SiO–AR–OSi(CH3)3 (AR = 4,4′-biphenylene (1) and 2,6-naphthylene (2)), with release of (CH3)3SiCl as a volatile byproduct, afforded novel hybrid materials that feature Si–O–C bridges. The precursors 1 and 2 were characterized using FTIR and multinuclear (1H, 13C, 29Si) NMR spectroscopy as well as single-crystal X-ray diffraction analysis in case of 2. Pyridine-catalyzed and non-catalyzed transformations were performed in THF at room temperature and at 60 °C. In most cases, soluble oligomers were obtained. The progress of these transsilylations was monitored in solution with 29Si NMR spectroscopy. Pyridine-catalyzed reactions with CH3SiCl3 proceeded until complete substitution of all chlorine atoms; however, no gelation or precipitation was found. In case of pyridine-catalyzed reactions of 1 and 2 with SiCl4, a Sol–Gel transition was observed. Ageing and syneresis yielded xerogels 1A and 2A, which exhibited large linear shrinkage of 57–59% and consequently low BET surface area of 10 m2⋅g−1. The xerogels were analyzed using powder-XRD, solid state 29Si NMR and FTIR spectroscopy, SEM/EDX, elemental analysis, and thermal gravimetric analysis. The SiCl4-derived amorphous xerogels consist of hydrolytically sensitive three-dimensional networks of SiO4-units linked by the arylene groups. The non-hydrolytic approach to hybrid materials may be applied to other silylated precursors, if the reactivity of the corresponding chlorine compound is sufficient.

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Section: Resultsmentioning

confidence: 99%

“…Synthesis of the starting materials. 4,4′-Bis(trimethylsiloxy)biphenyl ( 1 ): The compound was synthesized according to a procedure reported in the literature [ 65 ]. However, the brownish product was impure and had to be purified.…”

Section: Methodsmentioning

confidence: 99%

A Non-Hydrolytic Sol–Gel Route to Organic-Inorganic Hybrid Polymers: Linearly Expanded Silica and Silsesquioxanes

Krupinski

Wagler

Brendler

et al. 2023

Gels

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“…Phenols (Ismail, 1963;Langer et al, 1958) were the first compounds to be separated by gas chromatography as their silyl derivatives. Silyl ester derivatives have been used for identification of the anomers of pentoses and hexoses by gas chromatography (Bentley et al, 1963;Sweeley et al, 1963; Martin and Eib, 1968).…”

Section: Minedmentioning

confidence: 99%

Determination of fixed acids in commercial wines by gas-liquid chromatography

Martin¹,

Sullo²,

Schoeneman³

1971

J. Agric. Food Chem.

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Silicium enthaltende hitzebeständige Öle auf Fettsäure‐Basis

Ismail

1964

Fette, Seifen, Anstrichm.

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Aus Fettsaurederivaten und funktionellen Silanen wurden neuartige Organoorganoxysilane in guten Ausbeuten hergestellt. Die erhaltenen Ole vereinigen in sich die Eigenschaften herkommlicher Ole mit thermischer Bestandigkeit. Derartige Verbindungen lassen sich in vielen Bereichen der Technik als Hilfsmittel einsetzen. Silicium Containing Heat Resistant Oils on Fatty Acid BasisNew types of organoorganoxy silanes have been prepared in good yield from fatty acid derivatives and functional silanes. The oils obtained show properties of conventional oils with thermal stability. These types of compounds can be applied as auxiliary agent in various fields of technology.

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Notizen: Silylierung mit Hexamethyldisilazan

Cited by 10 publications

References 0 publications

A Non-Hydrolytic Sol–Gel Route to Organic-Inorganic Hybrid Polymers: Linearly Expanded Silica and Silsesquioxanes

A Non-Hydrolytic Sol–Gel Route to Organic-Inorganic Hybrid Polymers: Linearly Expanded Silica and Silsesquioxanes

Determination of fixed acids in commercial wines by gas-liquid chromatography

Silicium enthaltende hitzebeständige Öle auf Fettsäure‐Basis

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