Gold Mining by Alkanethiol Radicals: Vacancies and Pits in ...

Gold Mining by Alkanethiol Radicals: Vacancies and Pits in the Self-Assembled Monolayers of 1-Propanethiol and 1-Butanethiol on Au(111) Yun Wang † ∥, Qijin Chi ‡, Noel S. Hush † §, Jeffrey R. Reimers * †, Jingdong Zhang ‡, and ; Jens Ulstrup * ‡ View Author Information † School of Chemistry, The University of Sydney, Sydney 2006, Australia ‡ Department of Chemistry ...

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Nucleophilic character of alkyl radicals—IX : The benzyl ...

01.01.1973  Alkyi radicals have a clear-cut nucleophilic character, which increases from methyl to primary, secondary and tertiary alkyi radicals,2 revealed in macroscopic form only by suitable models in which the transition state is characterized by an adequate contribution of polar forms. Interaction of a nucleo- philic radical with a substrate. A, can be described either as R AR+A-, or (if A is positively

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III. Determining Radical Philicity - Chemistry LibreTexts

16.03.2021  Such an assessment allows alkyl radicals and car­bon-cen­tered radicals bearing electron-donating groups (e.g., CH 2 OH) to be identified as nuc­leo­philic. In a similar fashion, radicals such as RO, RCO 2 , R 2 N, Cl, F, and RS, which form anions by accepting electrons more easily than cations by electron loss, are designated as electro­philic.

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Alkoxyl-radical-mediated synthesis of functionalized allyl ...

03.05.2021  In conclusion, we found that the introduction of a silyl group to the α-position of alcohols can effectively inhibit β-carbon elimination of the corresponding (hetero)cyclobutoxyl radicals. The carbon radicals derived from 1,2-SiT were applied in the radical substitution reactions of functionalized allylic sulfones. The reaction showed broad substrate scope and could tolerate many base-sensitive

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Radical Biocatalysis: Using Non-Natural Single Electron ...

ductively cleave C–Br bonds to afford alkyl radicals that readily abstract a hydrogen atom from BNAH to afford the reduced product (Scheme 1). We recognized that if NADH displayed a similar reactivity profile, it would be possible to render radical dehalogenations asymmetric using nicotin-Figure 1 Strategies for revealing non-natural enzyme functions

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Kinetically guided radical-based synthesis of C(sp3)−C(sp3 ...

10.07.2018  The combined kinetic data under DEL-like conditions and literature precedence (for alkyl radical generated from N-hydroxyphthalimide esters via single electron-transfer, see, for example, refs, 56 and 57) allow the proposal of the productive reaction mechanism (Fig. 2F). The RAE is reduced via electron transfer from Zn, resulting in the formation of a radical anion that fragments into a carbon ...

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Kinetically guided radical-based synthesis of C(sp3) C(sp3 ...

Kinetically guided radical-based synthesis of C(sp3)−C(sp3) ... using genotoxic alkyl halide reagents as coupling partners (43 –46). Recentstudies havedemonstrated that the same disconnectioncan be accomplished through a tactically different one-electron strat-egy using ubiquitouscarboxylicacids(47–49) as latent nucleophiles with Michael acceptors (50–52). This potentially powerful ...

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ReaxFF molecular dynamics simulations of non-catalytic ...

The resulting alkyl and C 3 H 5 ˙ radicals further undergo recombination and decomposition to yield mainly alkanes and alkenes, with the actual product distribution being dependent on reaction temperature. β-Scission plays an important role in alkyl chain decomposition with a concomitant release of C 2 H 4. Compared to 1500 K, this reaction is accelerated at 2000 K. In addition, the formation of

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Autoxidation - an overview ScienceDirect Topics

The termination reactions involving combination of alkyl, alkoxyl, or peroxyl radical intermediates produce dimers with carbon– carbon, carbon ether, or peroxy links. The carbon–carbon and carbon–oxygen linked dimers are favored at elevated temperatures and the peroxy-linked dimers at ambient temperatures. The peroxy-linked dimers may also decompose to the ether-linked and carbon–carbon linked dimers via the corresponding alkyl and alkoxyl radical

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Ni/Co-Catalyzed Homo-Coupling of Alkyl Tosylates

A direct reductive homo-coupling of alkyl tosylates has been developed by employing a combination of nickel and nucleophilic cobalt catalysts. A single-electron-transfer-type oxidative addition is a pivotal process in the well-established nickel-catalyzed coupling of alkyl halides. However, the method cannot be applied to the homo-coupling of ubiquitous alkyl tosylates due to the high-lying σ*(C–O) orbital of

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Comparison of alkyl xanthates degradation in aqueous ...

01.10.2015  Hydroxyl radicals promote mineralization of xanthates by photolysis of O 3. Abstract. The removal of four alkyl xanthates (ethyl, isopropyl, n-butyl and n-amyl) by the O 3 and UV/O 3 processes was investigated in a semi-batch, bubble column reactor. Each alkyl xanthate was almost completely decomposed within 10 min by both the O 3 and UV/O 3 processes, confirmed by UV–vis

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The tert-butylchloride—lithium naphthalene radical anion ...

30.05.1997  Radical attack on naphthalene, Scheme 4 There is no doubt that, in the reaction between a radical anion with an alkyl halide, alkyl radicals are formed by an electron transfer step from the radical anion to the alkyl halide. In order then to understand the elementary steps of the reaction, we must bear in mind that the aromatic hydrocarbon which is derived from the radical anion after electron ...

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COMMUNICATION - Chemistry Europe

should produce an alkyl radical that could later couple. However, one good indicator of radical mechanisms is that all substituents are expected to provide stabilization and therefore should accelerate the reaction (i.e., most s values are positive). In this case, however, we can exclude radical involvement in the coupling step, since we ...

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Initiators for cationic polymerization - Minnesota Mining ...

03.09.1991  Minnesota Mining and Manufacturing Company (Saint Paul, MN) ... Preferably, each R will individually represent a perfluorinated alkyl radical or a perfluorinated aryl radical and most preferably, a C 1-C 10 perfluorinated alkyl radical. M is an element chosen from Groups 3-15, inclusive, of the Periodic Table as depicted in Chemical and Engineering News 1985, 63, 26. Preferably M is an

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Isse, Abdirisak A., Lin, Ching Yeh, Coote, Michelle L ...

Lin, Ching Yeh, Coote, Michelle L., Gennaro, Armando, Matyjaszewski, Krzysztof (2008) Ab Initio Evaluation of the Thermodynamic and Electrochemical Properties of Alkyl Halides and Radicals and Their Mechanistic Implications for Atom Transfer Radical Polymerization. Journal Of The American Chemical Society, 130 (38). 12762-12774 doi:10.1021 ...

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Ni-Catalyzed Reductive Carbonylation of Alkyl Halides to ...

The average mining thickness of the #3-5 coal seam in the Datong mining area is 15 m; therefore, the working face is easily connected with the above abandoned gob, where CO gas is accumulated by ...

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Micropatterning of Alkyl- and Fluoroalkylsilane Self ...

06.01.2000  Micropatterning of organosilane self-assembled monolayers (SAMs) was demonstrated on the basis of photolithography using an excimer lamp radiating vacuum ultraviolet light of 172 nm. This lithography is generally applicable to micropatterning of organic thin films including alkyl and fluoroalkyl SAMs, since its patterning mechanism involves cleavage of C−C bonds in organic molecules and ...

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(PDF) The polymerisation kinetics of lower dialkyl ...

Burnett et al.19) found from models that the alkyl group The constants of chain transfer to monomer, CM, in the screens the double bond in methacrylate molecules only polymerisation of dialkyl itaconates at 60 8C, given in very slightly, whereas with the corresponding radical in Tab. 3 and 4, are almost two orders of magnitude higher the propagating polymer there is considerable obstruc- than ...

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People The Buchwald Research Group

RD Manager, Pine, Oilfield and Mining Chemicals Georgia-Pacific Chemicals LLC, Decatur, Georgia ... Thesis: Copper(I)-Catalyzed Direct Borylation of Alkyl Halides. JSPS Postdoctral Fellowship for Research Abroad . Masami Kuriyama: Associate Professor Nagasaki University, Nagasaki, Japan 2005 : Kuriyama : Postdoctoral Researcher: Shin-itsu Kuwabe: Group head, Group 3 (Process Engineering)

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武汉大学药学院

Dissection of the neocarazostatin A C4 alkyl side chain biosynthesis by in vitro reconstitution. Organic Biomolecular Chemistry, 2017, 15(18): 3843-3848. 9.Ding W, Li Y, Zhao J, Ji X, Mo T, Qianzhu H, Tu T, Deng Z, Yu Y, Chen F, Zhang Q*. The Catalytic Mechanism of the Class C Radical S-Adenosylmethionine Methyltransferase NosN. Angew Chem ...

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halides - Yield of alkyl chloride in the Hunsdiecker ...

02.05.2021  Apparently the yield of alkyl chlorides is low as compared to that of alkyl bromides when preparing alkyl halides using the Hunsdiecker reaction. Why does this occur? The only factor I can see is the lower stability of the free radical of chlorine as compared to that of bromine, as the reaction proceeds by the free-radical mechanism.

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Angewandte Chemie: Early View - Wiley Online Library

A nickel-catalysed radical relay strategy combines radical rearrangement ... An efficient and fast photocatalytic procedure that enables the acylation/arylation of unfunctionalized alkyl derivatives in flow has been realized by combining decatungstate photocatalysis and nickel catalysis. The methodology shows great functional group tolerance and high regioselectivity, and can be used for the ...

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Thermophilic archaea activate butane via alkyl-coenzyme M ...

17.10.2016  In anaerobic bacteria, the radical-catalysed addition of alkanes to fumarate, yielding substituted succinates, is regarded as common 40,41, even

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Density Functional Theory Investigation of Possible ...

21.12.2016  We have performed a theoretical study, using density functional theory at the B3LYP/6-311G(d, p) level, of the possible radical types and their structures in coal and their stabilities once they come into contact with atmospheric O2 at ambient temperature. Eight possible radical types were proposed and explored through fully optimized electronic structure calculations.

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Brief Profile - ECHA

D-Glucopyranose, oligomeric, C10-16 (even... - Brief Profile - ECHA. Brief Profile. The Brief Profile summarizes the non-confidential data on substances as it is held in the databases of the European Chemicals Agency (ECHA), including data provided by third parties. The Brief Profile is automatically generated; note that it does not currently ...

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III. Organosilanes - Chemistry LibreTexts

16.03.2021  1. An Inefficient Hydrogen-atom transfer. Radical reactions with triethyl­si­lane (10) as the hydrogen-atom transfer are similar to those in which phenyl-substituted silanes fill this role in that repeated addition of substantial amounts initiator is neces­sary.The low reactivity of 10 as a hydrogen-atom transfer for carbon-centered radicals can be partially compensated for by using ...

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Aldol reaction - Wikipedia

A typical modern aldol addition reaction, shown above, might involve the nucleophilic addition of a ketone enolate to an aldehyde.Once formed, the aldol product can sometimes lose a molecule of water to form an α,β-unsaturated carbonyl compound.This is called aldol condensation.A variety of nucleophiles may be employed in the aldol reaction, including the enols, enolates, and enol ethers of ...

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Alkanes: Definition, Properties, Formula Examples ...

An alkyl group is a group of carbon and hydrogen atoms attached to an alkane molecule. Let's take a look at some examples of branched alkanes so we can picture them more clearly.

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Browse the Most-Read Articles of July 2021 - ACS Axial

24.08.2021  Reductive Radical Conjugate Addition of Alkyl Electrophiles Catalyzed by a Cobalt/Iridium Photoredox System DOI: 10.1021/acs.orglett.1c02114. Generation of Functionalized Alkyl Radicals via the Direct Photoexcitation of 2,2′-(Pyridine-2,6-diyl)diphenol-Based Borates DOI: 10.1021/acs.orglett.1c01996

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武汉大学药学院

Dissection of the neocarazostatin A C4 alkyl side chain biosynthesis by in vitro reconstitution. Organic Biomolecular Chemistry, 2017, 15(18): 3843-3848. 9.Ding W, Li Y, Zhao J, Ji X, Mo T, Qianzhu H, Tu T, Deng Z, Yu Y, Chen F, Zhang Q*. The Catalytic Mechanism of the Class C Radical S-Adenosylmethionine Methyltransferase NosN. Angew Chem ...

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