نتایج جستجو برای: silylation

تعداد نتایج: 439  

Journal: :Journal of chromatography. A 1999
J L Little

Trimethylsilyl derivatives are routinely employed in gas chromatography to increase the volatility and stability of organic compounds containing active hydrogens. Normally only the desired derivative is formed when organic compounds are derivatized with common silylation reagents. However, some compounds form additional unexpected derivatives or by-products (artifacts). Artifact formation leads...

2004
K. I. Arshak D. McDonagh A. Arshak B. P. Mathur

This paper describes the modelling and simulation of two resolution enhancement techniques in lithography ; 1) phase shift mask (PSM) technology and 2) top surface imaging (TSI) with silylation and dry development. The effect of the duty ratio on the image contrast is computed. Simulated one and two dimensional rim shifters and attenuated PSMs are presented. The effect of the aerial image on th...

Journal: :Dalton transactions 2015
Bogdan Marciniec Sylwia Kostera Bożena Wyrzykiewicz Piotr Pawluć

The ruthenium hydride complex-catalyzed N-silylation of primary and secondary amines with substituted vinylsilanes, with the general formula R(1)CH=CHSiR (where R(1) = H, Ph, n-Bu, Si(OEt)3), leading to the formation of a Si-N bond with the evolution of olefin is described. Vinylsilane acts as a silylative reagent and hydrogen acceptor. Under optimum conditions, the reaction offers an attractiv...

Journal: :Journal of chromatography. A 2007
Chih-Hung Wu Mei-Han Huang Sheng-Meng Wang Ching-Chiang Lin Ray H Liu

Method of chemical derivatization is the main difference among the GC-MS based methodologies reported for the analysis of ketamine and its major metabolites (norketamine and dehydronorketamine). These approaches included acylation and silylation resulting in the formation of acetyl, trifluoroacetyl, heptafluorobutyryl, and pentafluorobenzoyl (for acylation); and possibly trimethylsilyl and t-bu...

Journal: :Physical review letters 2008
Kiseok Chang Savas Berber David Tománek

We use ab initio density functional calculations to study the chemical functionalization of single-wall carbon nanotubes and graphene monolayers by silyl (SiH(3)) radicals and hydrogen. We find that silyl radicals form strong covalent bonds with graphene and nanotube walls, causing local structural relaxations that enhance the s p(3) character of these graphitic nanostructures. Silylation trans...

1,1’-(Ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) was used as a chemoselective and effective organocatalyst for the silylation of hydroxyl groups as well as desilylation of trimethylsilyl ethers under mild conditions at room temperature with good to excellent yields.

2001
Gary A. Molander

Metallocene complexes of the Group 3 metals and lanthanides have been utilized for cyclization/silylation reactions of polyunsaturated organic substrates. Acyclic dienes, trienes, enynes, and dienynes can be selectively cyclized to provide fiveand six-membered rings in high yields.

Journal: :Journal of Photopolymer Science and Technology 1998

2013
H. Aritani K. Kuramochi

A Mo-modified H-MFI zeolite (Mo/H-MFI) catalyst is one of a typical catalyst for direct GTL (Gas to liquid), because it shows high activity for dehydroaromatization of methane in absence of oxygen. In this reaction, reduction of Mo species is brought about in contact with methane in initial step, and reduced Mo ions react methane to form carbide and/or oxycarbide species in next step. It has be...

Journal: :Analytical chemistry 2004
Sunia A Trauger Eden P Go Zhouxin Shen Junefredo V Apon Bruce J Compton Edouard S P Bouvier M G Finn Gary Siuzdak

Silylation chemistry on porous silicon provides for ultrahigh sensitivity and analyte specificity with desorption/ionization on silicon mass spectrometry (DIOS-MS) analysis. Here, we report that the silylation of oxidized porous silicon offers a DIOS platform that is resistant to air oxidation and acid/base hydrolysis. Furthermore, surface modification with appropriate hydrophobic silanes allow...

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