Cyanogen halide

The coordination chemistry of hydrogen cyanide, cyanogen and cyanogen halides. B. Corain, Coord. Chem. Rev., 1982, 47,165-200 (111). 

Axen, R., Porath, J., and Ernback, S. (1967) Chemical coupling of peptides and proteins to polysaccharides by means of cyanogen halides. Nature (London) 214, 1302-1304. 

It can also be prepared from carbon and nitrogen by electric discharge between carbon electrodes in a nitrogen atmosphere. Numerous derivatives of cyanogens are known, including cyanogen halides, XCN. These compounds form trimers known as the cyanuric halides, which have the cyclic structure... 

The ring nitrogens react with electrophiles to afford either 1,3,4-thiadiazolium salts or l,3,4-thiadiazol-2(37/)-ones depending on the tautomerisability of the substituents at the C-2 or C-5 positions. While N-alkylation is the most common electrophilic reaction of 1,3,4-thiadiazoles, reactions with acyl and cyanogen halides as well as Mannich salts have also been reported. 

Effects from vapor exposure begin to appear 1-2 minutes after exposure. Pulmonary edema, caused by inhalation of cyanogen halides, does not occur until after a substantial latency period. 

High concentrations of cyanides and cyanogen halides can rapidly degrade elements of some air purification filters. Care should be taken whenever using APRs in the presence of these agents. 

Exposure to solid or liquid cyanogen halides can cause skin and eye irritation. Otherwise, casualties exposed to cyanides experience few effects at sublethal doses. Percutaneous absorption of a lethal dose may produce temporary rapid and deep breathing followed by convulsions and unconsciousness. Under these circumstances, the casualty will stop breathing within 2-4 minutes after exposure. Death will occur 4-8 minutes later. 

If cyanogen halides are suspected, asymptomatic individuals should be monitored for possible complications caused by pulmonary edema. 

IV,C. Bond energies of cyanogen halides have been calculated (8). 

The series of monomers NCO—CH2(CF2) CH2—OCN ( = 3, 4, 6, 8, 10) can be synthesized by the original method of Grigart and Piitter, in which a stoichiometric quantity of triethylamine is added to a cold solution of the alcohol and cyanogen halide (Reaction 1). 

D-Triazoles have been isolated from the reaction of several activated nitriles, such as cyanogen, cyanogen halides, methyl cyanoformate, and cyanic acid esters, with diazoalkanes. The reaction can formally be regarded as a 1,3-dipolar cycloaddition. The v-triazoles may be... 

Aryl cyanates585 can be prepared by reaction of phenols with cyanogen halides in the presence of a base ArO + C1CN — ArOCN + Cl. 586 This reaction has also been applied to certain alkyl cyanates.587... 

Mono- and di-thiocyanato-1,2,4-thiadiazoles, obtained by the stepwise action of cyanogen bromide on barium 3,5-dimercapto-l,2,4-thiadiazole, and on 5-chloro- and 5-hydroxy-3-mercapto-1,2,4-thiadiazole, are somewhat labile. The structures of certain of their transformation products (e.g. mono- and di-sulfides), which may have one of several isomeric forms, are not fully elucidated. The reactivity of their cyano group, resembling that in cyanogen halides, is noteworthy it is easily removed by the action of alkalis, the parent thiol being regenerated.202... 

Cyanuric halides are readily synthesized from the cyanogen halides. Cyanuric fluoride is formed at room temperature, whilst cyanuric chloride and cyanuric bromide are prepared... 

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