Dicyandiamide

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Structural formula
Structure of dicyanamide
General
Surname Dicyandiamide
other names
  • Cyanoguanidine
  • DCD
  • DICY
  • 1-cyanoguanidine
  • 2-cyanoguanidine
Molecular formula C 2 H 4 N 4
Brief description

white, odorless solid

External identifiers / databases
CAS number 461-58-5
EC number 207-312-8
ECHA InfoCard 100.006.649
PubChem 10005
Wikidata Q905401
properties
Molar mass 84.08 g · mol -1
Physical state

firmly

density

1.4 g cm −3

Melting point

208-210 ° C

boiling point

252 ° C (decomposition)

solubility
safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dicyandiamide ( DCD for short ) is a chemical compound from the group of cyanamides that is used in many ways as an intermediate .

Extraction and presentation

Dicyandiamide is formed when calcium cyanamide is broken down in the soil. It is produced industrially from cyanamide , technically from calcium cyanamide (calcium cyanamide) by reaction with carbon dioxide in an aqueous medium in the presence of alkalis .

One of the world's most important producers outside of China is AlzChem AG with an annual production volume of 20,000 tons of dicyandiamide at its Schalchen location .

In the laboratory, it is represented by dimerizing a warm cyanamide solution using a concentrated ammonia solution:

properties

Dicyandiamide is a flammable white odorless solid that is soluble in water (4.3% at 25 ° C). Chemically it belongs to the cyanamide and guanidine derivatives .

The compound occurs in two tautomeric forms. Some sources state that it is only in the dicyandiamide form according to the spectrum in the solid state.

Dicyandiamide tautomerism.png

use

Dicyandiamide is used as a synthetic building block for the production of plastics , fertilizers , pharmaceuticals and technical chemicals. It also serves as a hardener for hot-curing epoxy resin adhesives . It is also a raw material for forward-integrated intermediate products for the production of various guanidine salts , guanamines and polycondensation products for use in the areas of water treatment, textiles and leather, flame retardants and paper.

Dicyandiamide was previously used as an explosive in conjunction with strong oxidizing agents .

Biological importance

Dicyandiamide delays the nitrification of ammonium compounds to nitrate by Nitrosomonas and Nitrobacter and is therefore used as a nitrification inhibitor in agriculture. Ultimately, cyanguanidine is also broken down in the soil to form urea , but it can get into milk and milk products beforehand via grazing cattle.

Individual evidence

  1. ↑ a b c d Entry on dicyandiamide in the GESTIS substance database of the IFA , accessed on November 27, 2019(JavaScript required) .
  2. ↑ a b OECD : Screening Information Dataset (SIDS) Initial Assessment Report (SIAR) for guanidines, cyano- , accessed on November 4, 2014.
  3. ↑ a b c Claudia Synowietz (Ed.): Pocket book for chemists and physicists . founded by Jean d'Ans, Ellen Lax. 4th edition. Volume II: Organic Compounds . Springer, Berlin 1983, ISBN 3-540-12263-X .
  4. ↑ a b c Entry on cyanguanidine. In: Römpp Online . Georg Thieme Verlag, accessed on October 12, 2016.
  5. ↑ innsalzach24.de: Anniversary for a proven product: 1,000,000 tons of dicyandiamide , accessed on September 16, 2016.
  6. ↑ LA Pinck: Dicyanodiamide (cyanoguanidines) . In: Ludwig F. Audrieth (Ed.): Inorganic Syntheses . tape 3 . McGraw-Hill, Inc., 1950, pp. 43-45 (English).
  7. ↑ W. Jeremy Jones, WJ Orville-Thomas: The infra-red spectrum and structure of dicyandiamide. In: Transactions of the Faraday Society. 55, 1959, p. 193, doi: 10.1039 / TF9595500193 .
  8. ^ Dicyandiamide. In: alzchem.com. Retrieved June 29, 2017 .
  9. ↑ data sheet dicyandiamide (PDF; 127 kB) at gischem.de.
  10. ↑ effect. In: alzchem.com. Retrieved June 29, 2017 .