Synthesis of copper(I) cyanide (cuprous cyanide)

Preparation of copper(I) cyanide

Preparation of copper(I) cyanide (cuprous cyanide) by reducing copper sulfate with potassium cyanide and sodium bisulfite

Copper(I) cyanide is prepared by dissolving 500 grams of copper sulfate pentahydrate in 1600 ml at 40-50° C and placing in a 3-litre beaker. A solution of sodium bisulfite is prepared by dissolving 140 grams of sodium bisulfite in 400 ml of water and a solution potassium cyanide is prepared by dissolving 140 grams of commercial potassium cyanide in 400 ml of water. Both solutions are filtered, if necessary, from small amounts of insoluble residue. Sodium bisulfite and potassium cyanide solutions are separately warmed to 60° C. The copper sulfate solution should be acidified faintly to Congo red. The solution of sodium bisulfite is then added with mechanical stirring during 1-2 minutes, followed immediately by the solution of potassium cyanide. There is a slight frothing, a little sulfur dioxide is evolved. After about 10 minutes, the hot solution is filtered, the crude copper(I) cyanide is washed thoroughly with boiling water, and finally with ethanol. Copper(I) cyanide is dried at 100-110° C to a fine soft powder. The yield of copper(I) cyanide is 167 grams.

In order to prepare a copper(I) cyanide solution of known and definite concentration, a weighed amount of the dry copper(I) cyanide is dissolved in the necessary quantity (about 2 mols) of a solution of an alkali cyanide forming an almost colorless solution.

A text book of practical organic chemistry, by A. I. Vogel, 192, 1974

Preparation copper(I) cyanide from copper sulfate and potassium cyanide

50 g crystalline copper sulfate are dissolved in 300 ml hot water, and to this hot solution from a dropping funnel, a solution of 26 g potassium cyanide dissolved in 50 ml water is dropwise added. The reaction proceeds by evolving poisonous cyanogen gas and separation of white cheesy sediment of copper(I) cyanide. Copper(I) cyanide is separated by decanting from the faintly bluish-colored solution, washed with water and dried in a desiccator.

Laboratory manual of inorganic preparations, by H. T. Vulte, 74-75, 1895

Preparation of copper(I) cyanide solution

Copper(I) cyanide solution is prepared by dissolving 1 mole of copper(I) cyanide in a solution of technical sodium cyanide (2.5-2.6 mols of sodium cyanide in 600 ml of water).

In situ copper(I) cyanide solution is prepared from copper(I) chloride. 125 grams of copper sulfate pentahydrate and 32.5 grams of sodium chloride are dissolved in 400 ml of water (boiling may be necessary). An alkaline solution of sodium sulfite prepared from 26.5 grams of sodium bisulfite and 17.5 grams of sodium hydroxide in 200 ml of water or the solution of the sodium bisulfite alone is added to the resulting hot solution of copper dichloride during about 5 minutes with constant shaking. The copper(I) chloride solution will be decolorized or nearly so. The obtained solution is then cooled in an ice bath, and the supernatant liquid is decanted from the colorless copper(I) chloride. The precipitate of copper(I) chloride is washed twice by decantation with water containing a little dissolved sulfurous acid, in order to prevent oxidation. The obtained copper(I) chloride is suspended in 200 ml of water contained in a 1-litre round-bottomed flask, which is fitted with a mechanical stirrer. A solution of 65 g of technical sodium cyanide in 100 ml. of water is added and the mixture is stirred during the addition. The copper(I) chloride passes into solution with considerable evolution of heat forming the solution of copper(I) cyanide.

A text book of practical organic chemistry, by A. I. Vogel, 192, 1974





InChI Key


Canonical SMILES


Depositor-Supplied Synonyms

Copper(I) cyanide, 544-92-3, Copper(+1) cyanide, Cupricin, Copper cyanide (Cu(CN)), RCRA waste no. P029, RCRA waste number P029, HSDB 1438, EINECS 208-883-6, UN1587, AI3-28745, cyanocopper, copper(I)cyanide, copper(1)cyanide, copper (I)cyanide, copper(I)-cyanide, CuCN, Copper(1) cyanide, copper-(I) cyanide, copper-(I)-cyanide, copper (1) cyanide, KSC270A9F, 216305_ALDRICH, 61176_FLUKA, CTK1H0092, DULSAGLWMRMKCQ-UHFFFAOYSA-N, MolPort-001-756-359, 61176_SIAL, 216305_SIAL, ANW-32097, Copper cyanide [UN1587] [Poison], AKOS009031203, Copper cyanide [UN1587] [Poison], RTR-019271, BP-21032, LS-54872, TR-019271, C1952, I14-19137

Removed Synonyms

Cuprous cyanide, COPPER CYANIDE, Copper (I) cyanide, CID11009, IN1547, 13092-67-6

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