Chlorine cyanide, reaction

A jug containing calcium hypochlorite (probably as moist solid) was used as a disposal receptacle for cyanide wastes from student preparations of benzoin. When a little acetic acid residue was inadvertently added, an explosion occurred, attributed to a cyanide-chlorine redox reaction. 

This test is performed to determine the amount of cyanide in the sample that would react with chlorine. Not all cyanides in a sample are amenable to chlorination. While HCN, alkali metal cyanides, and CN- of some complex cyanides react with chlorine, cyanide in certain complexes that are tightly bound to the metal ions are not decomposed by chlorine. Calcium hypochlorite, sodium hypochlorite, and chloramine are some of the common chlorinating agents that may be used as a source of chlorine. The chlorination reaction is performed at a pH between 11 and 12. Under such an alkaline condition, cyanide reacts with chlorine to form cyanogen chloride, a gas at room temperature, which escapes out. Cyanide amenable to chlorination is therefore calculated as the total cyanide content initially in the sample minus the total cyanide left in the sample after chlorine treatment. 

Pentamethinestreptocymine Dyes are formed by reaction of bromine cyanide, chlorine cyanide, or 2,4-dinitrochlorobenzene with pyridine and cleavage of the resultant compounds with primary or secondary amines. The tetraacetal of gluta-conaldehyde is also used to form the methine chain [2], The dyes can be used to dye paper. 

A typical reaction condition for the alkaline chlorination of 1 kg (2.2 lb) of cyanide to cyanate requires 6 kg (13.2 lb) each of sodium hydroxide and chlorine. The reaction is carried out at pH 10, and at least 15 min contact time is required to drive the reaction to completion. If metal cyanide complexes are present, extended chlorination for longer periods may be necessary. Complete destruction of cyanate requires a second oxidation stage with approx 45 min retention at a pH below 8.5. The theoretical reagent requirement for this second stage is 4.1 kg (9.0 lb) of chlorine and 1.1 kg (2.4 lb) of caustic per kg (2.2 lb) of cyanide. 

CHLORINE CYANIDE (506-77-4) Violent polymerization can be caused by chlorine or moisture. Violent reaction with alcohols, acids, acid salts, amines, strong alkalis, olefins, strong oxidizers. In crude form, this chemical trimerizes violently if catalyzed by traces of hydrogen chloride or ammonium chloride. Prolonged storage may cause the formation of polymers. Alkaline conditions will convert this chemical to cyanide. Corrodes brass, copper, bronze. 

Donors of appropriate redox potential to react with holes at the anatase surface include organic acids, carbohydrates, fats, CN, and halides 2 ). (The cyanide reaction has been studied for its utility in treatment of the waste streams from Hold mininK operations in the Canadian Northwest Territories.) More immediately releyant to natural water is the observation that an anatase slurry could effect the decoloration of a chlorinated bleach plant effluent. A sample of amber colour, pH = 1.8, and low residual chlorine was irradiated in the presence of 0.5% (wt) anatase with li((ht of 350 nm for periods up to 18 hr. The optical absorbance decreased by half in 1080 min. Small amounts of chloride and formaldehyde were detected ( ). This reaction may provide a precedent for observation of a relation between photobleachinK of humics in water and metal ions. If so, we are brouj ht to the question of the reactivity of colloidal iron oxides. 

Chlorine cyanide, CICN, and excess nitrogen trifluoride at 450 to 500X yield (FCN)3, F3CN=NCF3, F3CNXF2, and CI2. Above 520X, the reaction occurs vigorously [7]. 

Alkyltrimethylsilylcarbodiimides [382] are the product of the reaction of alkyl-aminotriorganosilanes with chlorine cyanide in diethyl ether (Eq. 3.194) ... 

The reactions of the halogenated chain-fluorinated diazines with C-nucleophiles are less studied in comparison with N, S, 0- derivatives. The most actively used transformation is chlorine-cyanide exchange in a case of 4-chloro substituted pyrimidines (Table 49). In a case of nucleophilic catalysis by DMAP or DABCO the yields are in region 50-93 %. Withont nucleophilic catalysis the yields of the cyana-tion decreased extremely (Table 49, Entry 11). 

Dichloroacetic acid is produced in the laboratory by the reaction of chloral hydrate [302-17-0] with sodium cyanide (31). It has been manufactured by the chlorination of acetic and chloroacetic acids (32), reduction of trichloroacetic acid (33), hydrolysis of pentachloroethane [76-01-7] (34), and hydrolysis of dichloroacetyl chloride. Due to similar boiling points, the separation of dichloroacetic acid from chloroacetic acid is not practical by conventional distillation. However, this separation has been accompHshed by the addition of a eotropeforming hydrocarbons such as bromoben2ene (35) or by distillation of the methyl or ethyl ester. 

The cleavage products of several sulfonates are utilized on an industrial scale (Fig. 3). The fusion of aromatic sulfonates with sodium hydroxide [1310-73-2J and other caustic alkalies produces phenohc salts (see Alkylphenols Phenol). Chlorinated aromatics are produced by treatment of an aromatic sulfonate with hydrochloric acid and sodium chlorate [7775-09-9J. Nitriles (qv) (see Supplement) can be produced by reaction of a sulfonate with a cyanide salt. Arenesulfonates can be converted to amines with the use of ammonia. This transformation is also rather facile using mono- and dialkylamines. 

Nucleophilic Substitution. The kinetics of the bimolecular nucleophilic substitution of the chlorine atoms in 1,2-dichloroethane with NaOH, NaOCgH, (CH2)3N, pyridine, and CH COONa in aqueous solutions at 100—120°C has been studied (24). The reaction of sodium cyanide with... 

Molten sodium cyanide reacts with strong oxidizing agents such as nitrates and chlorates with explosive violence. In aqueous solution, sodium cyanide is oxidized to sodium cyanate [917-61 -3] by oxidizing agents such as potassium permanganate or hypochlorous acid. The reaction with chlorine in alkaline solution is the basis for the treatment of industrial cyanide waste Hquors (45) ... 

Nucleophilic substitution of the chlorine atom in 2-chloropyrazine and 2-chloroquinoxa-lines has been effected with a variety of nucleophiles, including ammonia and amines, oxygen nucleophiles such as alkoxides, sodium azide, hydrazine, sulfur containing nucleophiles, cyanide, etc., and reactions of this type are typical of the group (see Chapter 2.02). 

Corrective Action Application At a hazardous waste treatment storage and disposal facility in Washington State, a cyanide-bearing waste required treatment. The influent waste stream contained 15 percent cyanide. Electrolytic oxidation was used to reduce the cyanide concentration to less than 5 percent. Alkaline chlorination was used to further reduce the cyanide concentration to 50 mg/1 (the cleanup objective). The electrolytic process was used as a first stage treatment because the heat of reaction, using alkaline chlorination to treat the concentrated cyanide waste, would be so great that it would melt the reactor tank. 

The solid disulfide reacts explosively with chlorine or bromine. At low temperatures in certain non-aqueous solvents, e.g. chloroform, CISCSN3 and BrSCSN3 are probably formed, but the extreme instability of these compounds has precluded their exact analysis and description. However, the reaction between cyanogen bromide and the potassium salt of the thiol yields the well-defined cyanide NCSCSN3,... 

The vapor-phase chlorination reaction occurs at approximately 200-300°C. The dichlorobutene mixture is then treated with NaCN or HCN in presence of copper cyanide. The product 1,4-dicyano-2-butene is obtained in high yield because allylic rearrangement to the more thermodynamically stable isomer occurs during the cyanation reaction ... 

In its reactions SsO shows properties typical for both sulfur homocycles and sulfoxides. With elemental chlorine SOCI2 and S2CI2 are formed, with bromine SOBr2 and S2Br2 are obtained. Water decomposes SsO to H2S and SO2 besides elemental sulfur while cyanide ions expectedly produce thiocyanate. The reaction with iodide in the presence of formic acid is used for the iodometric determination of the oxygen content [70] ... 

Although active safety is provided by the control systems mentioned above, passive safety is an additional important feature of a distributed plant. Due to the low inventory, even a total release of the reaction volume or an explosion would create no significant impact on the environment [139]. To prevent such scenarios, a total containment of the plant is envisaged it needs to be sealed for life . Hydrogen cyanide synthesis and chlorine point-of-sale manufacture are two examples for safety-sensitive distributed syntheses. 

Schrader prepared the ester (38) in 60% yield by reaction of sodium p-nitrophenate with diethyl chlorophosphate, using xylene as solvent for the reaction. He made it, but in lower yields, from p-nitrophenol and diethyl chlorophosphate, using, respectively, pyridine and sodium cyanide as acceptors for hydrogen chloride. Schrader also prepared it in 96% yield by nitrating diethyl phenyl phosphate at 0° C. or below. Under the conditions he used, Schrader claims that the nitro group is directed to the para position. No yield is given for the diethyl phenyl phosphate, which he presumably made from sodium phenate and diethyl chlorophosphate. Diethyl chlorophosphate may be prepared in high yield (30) from diethyl phosphite and chlorine. 

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