Diamine


General structure of (primary) diamines. The primary amino groups (NH2) are marked blue,
R is a divalent organic radical (e.g. a para-phenylene group).

A diamine is an amine with exactly two amino groups. Diamines are used as monomers to prepare polyamides, polyimides, and polyureas. The term diamine refers mostly to primary diamines, as those are the most reactive.[1]

In terms of quantities produced, 1,6-diaminohexane (a precursor to Nylon 6-6) is most important, followed by ethylenediamine.[2] Vicinal diamines (1,2-diamines) are a structural motif in many biological compounds and are used as ligands in coordination chemistry.[3]

Geminal diamines (1,1-diamines) are usually reactive intermediates in transimination reactions and the reduction of amidines, in aqueous conditions they preferentially eliminate the less basic amine to leave an iminium ion.[4] Some stable geminal diamines have been isolated.[5]

  1. ^ "Nucleophilicity Trends of Amines". Master Organic Chemistry. 2018-05-07. Retrieved 2019-08-18.
  2. ^ Karsten Eller; Erhard Henkes; Roland Rossbacher; Hartmut Höke (2005). "Amines, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_001. ISBN 3-527-30673-0.
  3. ^ Lucet, D., Le Gall, T. and Mioskowski, C. (1998), The Chemistry of Vicinal Diamines. Angew. Chem. Int. Ed., 37: 2580–2627. doi:10.1002/(SICI)1521-3773(19981016)37:19<2580::AID-ANIE2580>3.0.CO;2-L
  4. ^ Moad, Graeme; Benkovic, S. J. (1 August 1978). "On the mechanism of decomposition of geminal diamines". Journal of the American Chemical Society. 100 (17): 5495–5499. doi:10.1021/ja00485a038. ISSN 0002-7863.
  5. ^ Aydın, Fatma; Arslan, N Burcu (5 September 2021). "Synthesis, spectral properties, crystal structure and theoretical calculations of a new geminal diamine: 2,2,2-Trichloro-N,N׳-bis(2-nitrophenyl)-ethane-1,1-diamine". Journal of Molecular Structure. 1232: 129976. doi:10.1016/j.molstruc.2021.129976.