نتایج جستجو برای: Hexamethyldisilazane (HMDS)
تعداد نتایج: 497 فیلتر نتایج به سال:
In a new type of reactivity for sodium TMP-zincate [(TMEDA)NaZn((t)Bu)(2)(TMP)] (1), transamination reactions with the amines diisopropylamine, DA(H), hexamethyldisilazane, HMDS(H) and chiral (R)-N-benzyl-alpha-methylbenzylamine have produced new sodium amido-di-tert-butyl zincates (all structurally characterised) with concomitant loss of TMP(H).
Trimethylsilylation of a variety of alcohols and phenols, in the presence of silica chloride, using hexamethyldisilazane (HMDS) in solution and under solvent-free conditions is reported. Trimethylsilyl ethers were formed in excellent yields both for aliphatic alcohols and phenols without having an electron-withdrawing group. In addition, SiO2-Cl can be recovered and reused after drying.
trimethylsilylation of a variety of alcohols and phenols, in the presence of silica chloride, using hexamethyldisilazane (hmds) in solution and under solvent-free conditions is reported. trimethylsilyl ethers were formed in excellent yields both for aliphatic alcohols and phenols without having an electron-withdrawing group. in addition, sio2-cl can be recovered and reused after drying.
OBJECTIVES The objectives of this study were to assess demineralized dentin porosity and quantify the different porous features distribution within the material using mercury intrusion porosimetry (MIP) technique. We compared hexamethyldisilazane (HMDS) drying and lyophilization (LYO) (freeze-drying) in sample preparation. METHODS Fifty-six dentin discs were assigned into three groups. The co...
Abstract The analysis of composition low-pressure (~0.1-1 mTorr) hollow cathode arc plasma in Ar+N2 gas mixture with Ti+hexamethyldisilazane vapors was carried out by optical emission spectroscopy. influence HMDS flow rate (1-10 g/h), discharge current (10-50 A) and Ti-vapors on hexamethyldisilazane decomposition degree investigated. proposed activation method provides both an intense a high me...
A simple and rapid reversed-phase high-performance liquid-chromatographic method for the separation and determination of process-related impurities of celecoxib (CXB) in bulk drugs and pharmaceuticals was developed. The separation of impurities viz., 4-methylacetophenone (I), 1-(4-methylphenyl)-4,4,4-trifluorobutane-1,3-dione (II), 4-hydrazinobenzene sulfonamide (III) and a regio-specific isome...
Trimethylsilylation of alcohols and phenols were carried out under solvent-free conditions with hexamethyldisilazane (HMDS) using LaCoO3 perovskite. LaCoO3 as an efficient catalyst accelerated this reaction under milder condition. The advantages of this method are evident regarding, easy separation, low cost and low catalyst loading, lack of pollution, easy work-up, and selective protection of ...
Superhydrophobic nanoporous anodic aluminum oxide (alumina) surfaces were prepared using treatment with vapor-phase hexamethyldisilazane (HMDS). Nanoporous alumina substrates were first made using a two-step anodization process. Subsequently, a repeated modification procedure was employed for efficient incorporation of the terminal methyl groups of HMDS to the alumina surface. Morphology of the...
This paper investigated the effects of critical-point drying (CPD) and hexamethyldisilazane (HMDS) sample preparation techniques for cervical cells on field emission scanning electron microscopy and energy dispersive X-ray (FE-SEM/EDX). We investigated the visualization of cervical cell image and elemental distribution on the cervical cell for two techniques of sample preparation. Using FE-SEM/...
in this research, different alcohols and phenols are subjected to the reaction with hmds in the presence of ionic liquid and silica-supported catalysts. silylation was accomplished under mild reaction conditions at room temperature in short reaction times and good to excellent yields.
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