Cyanogen
- Cyan
- Cyanogen
- Oxalsäuredinitril
- Oxalyldinitril
- Cyanogen
A colorless, pungent bitter almond-like smell gas
Gaseous
0.95 g · cm -3 (liquid, -21 ° C) 2.38 g · l-1 (gas, 0 ° C, 1013 mbar),
-27.83 ° C
-21.15 ° C
0.49 MPa (20 ° C)
- 45 g/100 ml ( 20 ° C)
- Soluble in ethanol and diethyl ether
Risk
5 ml · m- 3, 11 mg · m-3
350 ppm · 60 min -1 ( LC50, rat, inh. )
306.7 kJ / mol
Template: Infobox chemical / molecular formula search available
Cyanogen is a poisonous, gaseous chemical compound. It consists of two connected by a single bond cyanide groups. Briefly, they will be referred to as cyan or cyan.
History and habitat
Cyanogen was probably by Carl Wilhelm Scheele first synthesized in 1782, when he examined cyanide. Definitely, it was synthesized in 1802, as cyanogen chloride was prepared. Even before the generally recognized as such "first" synthesis of organic substances (urea, Friedrich Wöhler, 1828) F. Wöhler, the synthesis of oxalic acid by hydrolysis of cyanogen (1824 ).
Cyanogen was detected in 1910 in the tail of the then recurring Halley 's Comet.
Production and representation
In the laboratory, cyanogen is represented by heating mercury (II ) cyanide or silver cyanide, the complex salts Dicyanidoargentat (I ), K [Ag (CN ) 2] and Tetracyanidomercurat (II ) K2 [ Hg ( CN) 4 ] behave in the same direction.
And copper (II) salts can be used as the oxidant. Cyanide salts in the presence of cyanogen and these are oxidized to reduce the copper to Tetracyanocuprat (I).
Gold (III ) salts in water also react as a strong oxidizing agent against cyanides to form Kaliumdicyanidoaurat (I).
Cyanogen is formed in all electrolyses of cyanides or Cyanidokomplexen by anodic oxidation at pH 4-6 of inert platinum electrodes, the mechanism is similar to the Kolbe electrolysis.
Technically, it is obtained by the oxidation of hydrocyanic acid in which chlorine is used usually in an activated silica catalyst or nitrogen dioxide to copper salts. Cyanogen is formed from nitrogen and ethylene under the action of electric discharges.
Properties
Cyanogen is a linear molecule having a bond length of 116.3 pm (C- N) and 139.3 pm (C -C). The C -C bond is the strongest yet certain C- C single bond with a dissociation energy of 603 ( 21) kJ / mol.
Cyanogen is a colorless and poisonous, pungent - sweet- smelling gas with a boiling point of -21 ° C. It burns with a very hot (4800 K in pure oxygen ), red -violet flame. Cyanogen is chemically similar to a halogen and is therefore called a pseudo-halogen.
It dissolves slightly in water and it slowly disproportionates to hydrogen cyanide and cyanic acid in alkaline solution to form alkali metal salts thereof.
Cyanogen already polymerized at the sunlight or when heated to a firm, brown-black paracyanogen.
Cyanogen is easily flammable mixtures with air. The explosion range is between 3.9 vol - % (84 g/m3) as the lower explosive limit ( LEL) and 36.6 vol - % ( 790 g/m3 ) and upper explosive limit (UEL ).