Halogenation anodic

Cyanides. Salts of the complex ion, [Au(CN)2] , can be formed directiy from gold, ie, gold dissolves ia dilute solutions of potassium cyanide ia the presence of air. Additionally, a gold anode dissolves ia a solution of potassium cyanide. The potassium salt can be isolated by evaporation of the solution and purified by recrystallization from water (177). Boiling of the complex cyanide ia hydrochloric acid results ia formation of AuCN [506-65-01]. Halogens add oxidatively to [Au(CN)2] to yield salts of [Au(CN)2X2] which are converted to the tetracyanoaurates usiag excess cyanide (178). These last can also be prepared directiy from the tetrahaloaurates. 

Electrolysis, Ni(II), Mg anode. DMF, it 77-99% yield. This method is not compatible with halogenated phenols, because of competing halogen cleavage. ... 

In the case of electrochemical reactions the partial anodic reaction results in the formation of a solvated metal cation, a charged or uncharged metal complex MX or a solid compound MX, where AT is a halogen ion, organic acid aninn, etc. 

The physicochemical properties of carbon are highly dependent on its surface structure and chemical composition [66—68], The type and content of surface species, particle shape and size, pore-size distribution, BET surface area and pore-opening are of critical importance in the use of carbons as anode material. These properties have a major influence on (9IR, reversible capacity <2R, and the rate capability and safety of the battery. The surface chemical composition depends on the raw materials (carbon precursors), the production process, and the history of the carbon. Surface groups containing H, O, S, N, P, halogens, and other elements have been identified on carbon blacks [66, 67]. There is also ash on the surface of carbon and this typically contains Ca, Si, Fe, Al, and V. Ash and acidic oxides enhance the adsorption of the more polar compounds and electrolytes [66]. 

N 24.12% brick red solid mp, decomps when heated over 300°. Insol in w and the usual organic solvents as well as weak acids and alkalies. Comm prepn (Ref 3) is from thiocyanic acid and/or thiocyanates either by anodic oxidation or by interaction with hydrogen peroxide or halogens. The yield is impure because it contains both H and O. The S content varies between 45 and 55%. Lab prepn of the pure polymer is by reacting the Na salt of 5-chlor-3-mercapto 1,2,4-thiodiazols with either acet, ethanol or w (Refs 1 2)... 

Oxidation of thiophene with Fenton-like reagents produces 2-hydroxythiophene of which the 2(570 One isomer is the most stable (Eq. 1) <96JCR(S)242>. In contrast, methyltrioxorhenium (Vn) catalyzed hydrogen peroxide oxidation of thiophene and its derivatives forms first the sulfoxide and ultimately the sulfone derivatives <96107211>. Anodic oxidation of aminated dibenzothiophene produces stable radical cation salts <96BSF597>. Reduction of dihalothiophene at carbon cathodes produces the first example of an electrochemical halogen dance reaction (Eq. 2) <96JOC8074>. 

Anodic oxidation of halogenated tyrosines was studied in connection with some sponge metabolites (cavemicolin model compounds). The methyl exter of 3,5-dibromotyrosine afforded four different products in a 41 10 26 23 ratio with 23% overall yield as a result of equilibration. (Scheme 44) [93JCS(P2)3117], A related compound was obtained as a mixture of stereoisomers 56 from a Diels-Alder reaction between N-acetyldehydroalanine methyl ester and l-methoxy-l,3-cyclohexadiene (87TL2371). 

In these reactions (Scheme 3.1), the first electron addition is to the alkene giving a radical-anion. This interacts with the alkyl halide to transfer an electron, in a process driven by simultaneous cleavage of the carbon-halogen bond. The alkyl radical formed in this manner adds an alkene radical-anion [25]. Aluminium ions generated at the anode are essential to the overall process. They coordinate with the intermediate carbanion, which then interacts with the second halogen substituent in an Sn2 process to form the carbocycle. 

Carbon-Halogen Bond Reactions Catalysed by the Anode Material... 

Formation of carboxylic acids by reduction in dimethylformamide of the carbon-halogen bond in die presence of carbon dioxide and using sacrificial anodes. 

Moissan reasoned that if he were trying to liberate chlorine he would not choose a stable solid like sodium chloride, but a volatile compound like hydrochloric acid or phosphorus pentachloride. His preliminary experiments with silicon fluoride convinced him that this was a very stable compound, and that, if he should ever succeed in isolating fluorine, it would unite with silicon with incandescence, and that therefore he might use silicon in testing for the new halogen. After many unsuccessful attempts to electrolyze phosphorus trifluoride and arsenic trifluoride, and after four interruptions caused by serious poisoning, he finally obtained powdered arsenic at the cathode and some gas bubbles at the anode. However, before these fluorine bubbles could reach the surface, they were absorbed by the arsenic trifluoride to form pentafluoride (18, 23). 

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