Nitrogen cyanogen

Carbon will react readily with sulfur at red heat to form carbon disulphide, CS2, but it does not react directly with nitrogen. Cyanogen, (CN)2, must be prepared by heating covalent metal cyanides such as CuCN. Carbon will also react directly with many metals at elevated temperatures to give CARBIDES. Carbides can also be ob-... 

A solution of 0.40 mol of ethyllithium in about 350 ml of diethyl ether (see Chapter II, Exp. 1) was transferred into the flask, which previously had been filled with nitrogen. The solution was cooled to -50°C and a cold solution (-30°C) of 0.43 mol of propyne in 50 ml of dry diethyl ether was added at a rate such that the temperature could be kept below -20°C. A solution of 0.45 mol of cyanogen chloride in 100 ml of diethyl ether, cooled at about 0°C, was then added in... 

Cyanide destmction by alkaline chlorination is a widely used process. With alkaline chlorination, cyanide is first converted to cyanate with hypochlorite [7681-52-9] at a pH greater than 10. A high pH is required to prevent the formation of cyanogen chloride [506-77-4] which is toxic and may evolve in gaseous form at a lower pH. With additional hypochlorite, cyanate is then oxidized to bicarbonate, nitrogen gas, and chloride. The pH for this second stage is 7—9.5 (6). 

The pH value is usually maintained above 9 to avoid formation of nitrogen trichloride. At lower pH values, aqueous solutions react with chlorine to form cyanogen chloride (52). 

Azoles can form stable compounds in which metallic and metalloid atoms are linked to nitrogen. For example, pyrazoles and imidazoles Af-substituted by B, Si, P and Hg groups are made in this way. Imidazoles with a free NH group can be Af-trimethylsilylated and Af-cyanated (with cyanogen bromide). Imidazoles of low basicity can be Af-nitrated. 

A solution of 5 g (14 mmoles) of 5a-cholest-2-ene in 100 ml ethyl acetate and 8 ml of 2.8 M (22 mmoles) cyanogen azide (CAUTION See Chapter 15 and ref. 139b) in ethyl acetate is heated at 50-53° for 24 hr, during which time about 22 mmoles of nitrogen is evolved. Solvent is removed by evaporation and the residue is applied in benzene to a column of 160 g of neutral alumina (activity grade III). Elution with petroleum ether-benzene (1 1) gives 1.6 g of... 

The reaction of cyanogen azide with enamines of cyclic ketones to yield a cyanoamidine with one less member in the carbocyclic ring represents a potentially valuable method of ring contraction under mild conditions (199a). The reaction probably proceeds first by 1,3 cycloaddition of the azide to the enamine followed by rearrangement and elimination of a molecule of nitrogen. 

It is usual to protect carbon from oxidation at high temperature by the use of alternative gas atmospheres — these are generally hydrogen, nitrogen, argon or helium. The first two will react at temperatures above 1700°C to form methane and cyanogen, respectively. 

Cyanogen gas, CjN has been found in foe gases of outer space. It can react with fluorine to form carbon tetrafluoride and nitrogen trifluoride. 

In the blast furnace, the reaction of the nitrogen in the blast with coke leads to the formation of poisonous chemicals such as hydrogen cyanide and cyanogens, and each cubic meter of the blast furnace gas contains from 200 to 2000 mg of these compounds. The blast furnace gas is scrubbed with water in the dust collection system the cyanide compounds dissolve in the water, which is then discharged after the compounds have been destroyed. Another poisonous emission in blast furnace operations is hydrogen sulfide. The sulfur present in the coke is converted into calcium sulfide in the slag, the water-quenching of... 

The most common compound of carbon and nitrogen is cyanogen, (CN)2. The cyanide ion, CN , is a pseudohalide ion, which means that it resembles a halide ion because it forms an insoluble silver compound and it can be oxidized to the X2 species. Cyanogen was first obtained by Gay-Lussac in 1815 by heating heavy-metal cyanides. 

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. 

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