Electrochemistry of metals and semiconductors in fluoride media

Monofluoro dimethyl glutarate has been successfully synthesized for the first time by electrochemical fluorination. It is done in an undivided polypropylene cell with platinum electrodes. Initially at three different current densities, dimethyl glutarate is subjected to electrofluorination. Maximum yield of monofluoro product is obtained at 15 mA cm −2 . Selecting this current density, electrosynthesis is done at three different charges. Maximum yield of 71.5% of the monofluoro product is obtained with a conversion efficiency of 95.2% when the charge of 6 F/mol is passed. The synthesized product is characterized using Fourier transform infrared (FTIR), gas chromatography/mass spectrometry (GC/MS), and nuclear magnetic resonance (NMR). The product purity and composition are ascertained using GC/MS. The attachment of fluorine to methylene group is indicated using FTIR data. From NMR studies, the environment of fluorine in the neighborhood of carbon and hydrogen has been established. Results are discussed in the paper.

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“…These studies indicate high selectivity toward fluorination of active methylene group attached to sulfur atom [5][6][7][8].…”

Section: Introductionmentioning

confidence: 78%

“…Partial fluorination of aromatic compounds by electrochemical method in fluoride containing solvent-free electrolyte systems has been extensively studied and reviewed [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Electrochemical fluorination of dimethyl glutarate and its characterization

Ilayaraja

Radhakrishnan

Renganathan

2009

Ionics

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“…Usually, Mo, W, Mo 2 C, and W 2 C coatings are deposited onto non-oriented metal substrates by electrolysis of Na 2 WO 4 -based oxide melts [1][2][3][4]. However, in many instances it is necessary to obtain continuous cathode deposits with preset properties (structure, orientation, and crystallite size).…”

Section: Introductionmentioning

confidence: 99%

Initial stages of nucleation of molybdenum and tungsten carbide phases in tungstate–molybdate–carbonate melts

2007

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The electrochemical nucleation of Mo 2 C and W 2 C crystals for tungstate-molybdate-carbonate melts of specific compositions on Ag, Au, Cu, Pt, and Ni substrates was studied by the electrodeposition method. The influence of electrocrystallization conditions (temperature, deposition time, initial current pulse, and current density) was investigated. Experimental measurements indicate that crystallization overvoltage is associated with threedimensional nucleation. Carbide deposition onto the substrates prepared from the same solid materials was not associated with crystallization overvoltage. The maximum value of the initial overvoltage, g max , which includes crystallization and electrolysis overvoltages, is proportional to the electrode surface area. Under these conditions, surface diffusion limits the electrode process rate. An increase in carbide deposition rate leads to an increase in the number of crystallization centers. This reduces the duration of surface diffusion. A rise in the melt temperature complicates the crystallization process by alloy-formation phenomena. Overvoltage maximum height for metals, which do not form alloys, is proportional to the reciprocal of their formation time. Melt temperature increase promotes interdiffusion of refractory metal, carbon, and substrate, and also intensifies their chemical interaction. Structural mismatch is observed during molybdenum and tungsten carbide electrodeposition onto different singlecrystal substrates.

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“…lower temperatures with less degradation of feed and/or product; fewer processing steps (for example, electrochemical synthesis and product separation may be combined in one reactor); precise control of oxidation or reduction level by control of electrode potential; discovery of unique processing routes to establish or re-establish control of the market position. [6][7][8][9][10][11][12][13][14][15][16] In any worthwhile comparison of the advantages of chemical vs. electrochemical alternatives, it is obvious that the relative economics, the market, product selectivity and other factors must be considered. Certainly, electrochemical routes are not always economically feasible, especially when the competitor is a catalytic chemical route based upon O 2 or H 2 .…”

Section: Introductionmentioning

confidence: 99%

Electrochemical routes for industrial synthesis

Sequeira¹,

Santos²

2009

J. Braz. Chem. Soc.

119

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Esta revisão examina as razões que justificam um interesse crescente da indústria química pelos processos eletrolíticos. Reveem-se as indústrias químicas, nas quais compostos orgânicos e inorgânicos são processados e descrevem-se os avanços tecnológicos mais relevantes. Inicialmente, abordam-se processos bem estabelecidos, como as indústrias cloroalcalinas de produção de alumínio, p-aminofenol, adiponitrila, etileno glicol, antraquinona, produtos perfluorados, ácido glioxílico e L-cisteína. Face à grande quantidade de informação disponível, o assunto é tratado com base científica, mas de modo bastante simplificado. Posteriormente, descrevem-se processos orgânicos e inorgânicos emergentes, nomeadamente processos eletroquímicos mediados e síntese em líquidos iónicos. Estabelecem-se paralelos entre síntese química e síntese eletroquímica. Estimula-se o interesse nos processos de eletrossíntese, particularmente em líquidos iónicos, não desmerecendo a importância das vias puramente químicas de síntese orgânica e inorgânica.This review examines the reasons for increasing interest towards electrolyses by the chemical industry, reviews the electrochemical industries as most of them now exist, and provides a status report on the key technological advances which are occurring to meet present and future needs. Classical industries like those of chloroalkali, aluminium, p-aminophenol, adiponitrile, ethylene glycol, anthraquinone, perfluorinated products, glyoxylic acid and L-cysteine are initially covered. Considering the large amount of available publications in these topics of electrochemical engineering, the covered relevant information is treated at a scientific level, although in a simplified way. Then the paper deals with emerging inorganic and organic processes, e.g. electrosynthesis in ionic liquids and mediated electrochemical processes, and finishes by assessing what the future development trend might be given the electrochemical and non electrochemical competing influences. With this approach it is hoped to stimulate the interest of chemical engineers and scientists non-specialised in electrochemical routes, and to review some cutting edge research, particularly as far as electrosynthesis in ionic liquids is concerned.

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Electrochemistry of metals and semiconductors in fluoride media

Cited by 15 publications

References 182 publications

Electrochemical fluorination of dimethyl glutarate and its characterization

Electrochemical fluorination of dimethyl glutarate and its characterization

Initial stages of nucleation of molybdenum and tungsten carbide phases in tungstate–molybdate–carbonate melts

Electrochemical routes for industrial synthesis

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