diamine

• 2 carbon backbone: ethylenediamine (1,2-diaminoethane). Related derivatives include the N-alkylated compounds, 1,1-dimethylethylenediamine, 1,2-dimethylethylenediamine, ethambutol, tetrakis(dimethylamino)ethylene, TMEDA. Many 1,2-diamine derivatives are of practical interest such as penicillin.{{cite journal |doi=10.1111/j.1747-0285.2006.00347.x |title=Vicinal Diamino Functionalities as Privileged Structural Elements in Biologically Active Compounds and Exploitation of their Synthetic Chemistry |date=2006 |last1=Saibabu Kotti |first1=S. R. S. |last2=Timmons |first2=Cody |last3=Li |first3=Guigen |journal=Chemical Biology & Drug Design |volume=67 |issue=2 |pages=101–114 |pmid=16492158 }}{{cite journal |doi=10.1002/(SICI)1521-3773(19981016)37:19<2580::AID-ANIE2580>3.0.CO;2-L |title=The Chemistry of Vicinal Diamines |date=1998 |last1=Lucet |first1=Denis |last2=Le Gall |first2=Thierry |last3=Mioskowski |first3=Charles |journal=Angewandte Chemie International Edition |volume=37 |issue=19 |pages=2580–2627 |pmid=29711625 }}

Image:Ethylenediamine.svg

• 3 carbon backbone: 1,3-diaminopropane (propane-1,3-diamine)
• 4 carbon backbone: putrescine (butane-1,4-diamine)
• 5 carbon backbone: cadaverine (pentane-1,5-diamine)

image:Pentane-1,5-diamine 200.svg|thumb]]

• 6 carbon backbone: hexamethylenediamine (hexane-1,6-diamine, HMD). HMD and other long chain diamines can be prepared by hydrocyanation to give dinitrile, which can be hydrogenated.{{cite book |doi=10.1002/14356007.a04_431.pub2 |chapter=Butadiene |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2011 |last1=Dahlmann |first1=Marc |last2=Grub |first2=Joachim |last3=Löser |first3=Eckhard |pages=1–24 |isbn=978-3-527-30673-2 }}

Derivatives of ethylenediamine are prominent:

• 1,2-diaminopropane, which is chiral.
• 2,3-Butanediamine, two diastereomers, one of which is C₂-symmetric.
• Diphenylethylenediamine, two diastereomers, one of which is C₂-symmetric.
• trimethylhexamethylenediamine, several isomers
• 1,2-Diaminocyclohexane, two diastereomers, one of which is C₂-symmetric.

image:DACH.png

• piperazine ({{chem2|(CH2CH2NH)2}})
• 1,4-Diazacycloheptane

Xylylenediamines are classified as alkylamines since the amine is not directly attached to an aromatic ring.

• o-xylylenediamine or OXD
• m-xylylenediamine or MXD
• p-xylylenediamine or PXD

Three phenylenediamines are known:Robert A. Smiley "Phenylene- and Toluenediamines" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a19_405}}

• o-phenylenediamine or OPD
• m-phenylenediamine or MPD
• p-phenylenediamine or PPD. 2,5-diaminotoluene is related to PPD but contains a methyl group on the ring.

image:P-phenylenediamine.svg

Various N-methylated derivatives of the phenylenediamines are known:

• dimethyl-4-phenylenediamine, a reagent.
• N,N'-di-2-butyl-1,4-phenylenediamine, an antioxidant.

Examples with two aromatic rings include derivatives of biphenyl and naphthalene:

• 4,4'-diaminobiphenyl
• 1,8-diaminonaphthalene

File:Wurster's cation.svg, illustrating the ability of amino substituents to stabilize arene radical cations.]]

image:Me2NCH2NMe2.svg

Geminal diamines (1,1-diamines) are an unusual class of diamines mainly of academic interest. Bis(dimethylamino)methane ([(CH₃)₂N]₂CH₂) is a stable example.

Geminal diamines with N-H bonds are particularly rare. They are invoked as intermediates in transimination reactions and the reduction of amidines. In aqueous conditions they preferentially eliminate the less basic amine to leave an iminium ion.{{Cite journal |last=Moad |first=Graeme |last2=Benkovic |first2=S. J. |date=1 August 1978 |title=On the mechanism of decomposition of geminal diamines |url=https://pubs.acs.org/doi/abs/10.1021/ja00485a038 |journal=Journal of the American Chemical Society |language=en |volume=100 |issue=17 |pages=5495–5499 |doi=10.1021/ja00485a038 |issn=0002-7863|url-access=subscription }} Some stable geminal diamines have been isolated.{{Cite journal |last=Aydın |first=Fatma |last2=Arslan |first2=N Burcu |date=5 September 2021 |title=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 |url=https://linkinghub.elsevier.com/retrieve/pii/S0022286021001071 |journal=Journal of Molecular Structure |language=en |volume=1232 |pages=129976 |doi=10.1016/j.molstruc.2021.129976|url-access=subscription }} The parent gem-diamine is methylenediamine (diaminomethane), which again is mainly of theoretical interest.

• {{MeshName|Diamines}}
• [https://www.organic-chemistry.org/synthesis/C1N/amines/diamines.shtm Synthesis of diamines]

Category:Monomers