Isocyanate group

The isocyanate group , and NCO group consisting of a nitrogen - atom having a free valence which a double bond to a carbon bonded atom, which in turn via a further double bond to an oxygen binds atom. This group is part of the isocyanates .

synthesis

For the synthesis of organic isocyanates R-N = C = O (R = organyl radical), primary amines R-NH ₂ with phosgene COCl ₂ implemented. Analogously, α, ω- diisocyanates can be prepared from primary α, ω-diamines and phosgene.

Reactivity

Organic isocyanates react with primary amines (R – NH ₂ ) in an addition reaction to form ureas . The reaction of isocyanates with alcohols (R – OH) produces urethanes .

Economical meaning

The polyaddition of α, ω- diisocyanates with diols and / or triols yields polyurethanes that are used in many ways as construction foam , in automobile construction (shock absorbers, dashboard lining) and as shoe soles.

Individual evidence

↑ Joachim Buddrus, Bernd Schmidt: Basics of Organic Chemistry , 5th edition, de Gruyter Verlag, Berlin, 2015, pp. 682–683, ISBN 978-3-11-030559-3 .
^ Siegfried Hauptmann : Organic Chemistry , 2nd revised edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 738, ISBN 3-342-00280-8 .
^ MD Lechner, K. Gehrke and EH Nordmeier: Makromolekulare Chemie , 4th edition, Birkhäuser Verlag, 2010, pp. 136-138, ISBN 978-3-7643-8890-4 .

[Buddrus-1] Joachim Buddrus, Bernd Schmidt: Basics of Organic Chemistry , 5th edition, de Gruyter Verlag, Berlin, 2015, pp. 682–683, ISBN 978-3-11-030559-3 .

[Hauptmann-2] Siegfried Hauptmann : Organic Chemistry , 2nd revised edition, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig, 1985, p. 738, ISBN 3-342-00280-8 .

[Lechner-3] MD Lechner, K. Gehrke and EH Nordmeier: Makromolekulare Chemie , 4th edition, Birkhäuser Verlag, 2010, pp. 136-138, ISBN 978-3-7643-8890-4 .