A diamine is a type of polyamine

Polyamine

A polyamine is an organic compound having two or more primary amino groups .This class of compounds includes several synthetic substances that are important feedstocks for the chemical industry, such as ethylene diamine , 1,3-diaminopropane , and hexamethylenediamine...

 with exactly two amino groups. Diamines are mainly used as monomers to prepare polyamide

Polyamide

A polyamide is a polymer containing monomers of amides joined by peptide bonds. They can occur both naturally and artificially, examples being proteins, such as wool and silk, and can be made artificially through step-growth polymerization or solid-phase synthesis, examples being nylons, aramids,...

s, polyimide

Polyimide

Polyimide is a polymer of imide monomers. The structure of imide is as shown. Polyimides have been in mass production since 1955...

s and polyurea

Polyurea

Polyurea is a type of elastomer that is derived from the reaction product of an isocyanate component and a synthetic resin blend component through step-growth polymerization. The isocyanate can be aromatic or aliphatic in nature. It can be monomer, polymer, or any variant reaction of isocyanates,...

s. In terms of quantities produced, 1,6-diaminohexane, a precursor to Nylon 6-6

Nylon 6-6

Nylon 6-6, also referred to as nylon 6,6, is a type of nylon. Nylon comes in many types, the two most common for textile and plastics industries are: nylon 6 and nylon 6,6.- Composition :...

, is most important, followed by ethylenediamine. Hydrazine

Hydrazine

Hydrazine is an inorganic compound with the formula N2H4. It is a colourless flammable liquid with an ammonia-like odor. Hydrazine is highly toxic and dangerously unstable unless handled in solution. Approximately 260,000 tons are manufactured annually...

 (H₂NNH₂) is usually not considered a diamine since it is neither an amine nor is it dibasic.

Linear aliphatic diamines

• 2 carbons: ethylenediamine (1,2-diaminoethane). Related derivatives include the N-alkylated compounds ethambutol
  Ethambutol
  Ethambutol is a bacteriostatic antimycobacterial drug prescribed to treat tuberculosis. It is usually given in combination with other tuberculosis drugs, such as isoniazid, rifampicin and pyrazinamide....
  
   and TMEDA.
• 3 carbons: 1,3-diaminopropane
  1,3-Diaminopropane
  1,3-Diaminopropane is a simple amine. The potassium salt is used in the alkyne zipper reaction, first reported by Charles Allen Brown and Ayako Yamashita in 1975....
  
   (propane-1,3-diamine)
• 4 carbons: putrescine
  Putrescine
  Putrescine is a foul-smelling organic chemical compound NH24NH2 that is related to cadaverine; both are produced by the breakdown of amino acids in living and dead organisms and both are toxic in large doses...
  
   (butane-1,4-diamine)
• 5 carbons: cadaverine
  Cadaverine
  Cadaverine is a foul-smelling compound produced by protein hydrolysis during putrefaction of animal tissue. Cadaverine is a toxic diamine with the formula NH25NH2, which is similar to putrescine...
  
   (pentane-1,5-diamine)
• 6 carbons: hexamethylenediamine
  Hexamethylenediamine
  Hexamethylenediamine is the organic compound with the formula H2N6NH2. The molecule is a diamine, consisting of a hexamethylene hydrocarbon chain terminated with amine functional groups. The colorless solid has a strong amine odor, similar to piperidine...
  
   (hexane-1,6-diamine)

Branched aliphatic diamines

Derivatives of ethylenediamine are numerous:

• 1,2-diaminopropane
• diphenylethylenediamine
  Diphenylethylenediamine
  1,2-Diphenyl-1,2-ethylenediamine is an organic compound with the formula H2NCHPhCHPhNH2, where Ph is C6H5, phenyl. This diamine is a precursor to a ligand for certain homogeneous hydrogenation catalysts...
  
  
• diaminocyclohexane

Xylylenediamines

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

Aromatic diamines

Three phenylenediamine

Phenylenediamine

Phenylenediamine may refer to:*o-phenylenediamine or OPD, a chemical compound C6H42*m-phenylenediamine or MPD, a chemical compound C6H42*p-phenylenediamine or PPD, a chemical compound C6H42...

s are known:

• o-phenylenediamine
  O-Phenylenediamine
  o-Phenylenediamine is a organic compound with the formula C6H42. This aromatic diamine is an important precursor to many heterocyclic compounds...
  
   or OPD
• m-phenylenediamine
  M-Phenylenediamine
  m-Phenylenediamine, also called 1,3-diaminobenzene, is an organic compound with the formula C6H42. It is an isomer of o-phenylenediamine and p-phenylenediamine. It is a colourless solid.-Production:...
  
   or MPD
• p-phenylenediamine
  P-Phenylenediamine
  p-Phenylenediamine is an organic compound with the formula C6H42. This derivative of aniline is a colorless solid, but typically samples can contain yellowish impurities arising from oxidation. It is mainly used as a component of engineering polymers and composites. It is also an ingredient in...
  
   or PPD. 2,5-Diaminotoluene
  2,5-Diaminotoluene
  2,5-Diaminotoluene is an organic compound with the formula C6H32CH3. It is one isomer of six with this formula. 2,5-Diaminotoluene is a colorless crystalline solid that is commonly used in hair coloring.- Formation and use:...
  
   is related to PPD but contains a methyl group on the ring.

Various N-methylated derivatives of the phenylenediamines are known:

• dimethyl-4-phenylenediamine
  Dimethyl-4-phenylenediamine
  Dimethyl-4-phenylenediamine is a molecule used in the oxidase test....
  
  , a reagent.
• N,N'-di-2-butyl-1,4-phenylenediamine
  N,N'-Di-2-butyl-1,4-phenylenediamine
  N,N-Di-2-butyl-1,4-phenylenediamine is an aromatic amine used industrially as an antioxidant to prevent degradation of turbine oils, transformer oils, hydraulic fluids, lubricants, waxes, and greases. It is particularly effective for hydrocarbon products produced by cracking or pyrolysis, which are...
  
  , an antioxidant.

Examples with two aromatic rings include derivatives of biphenyl

Biphenyl

Biphenyl is an organic compound that forms colorless crystals. It has a distinctively pleasant smell. Biphenyl is an aromatic hydrocarbon with a molecular formula 2...

 and naphthalene

Naphthalene

Naphthalene is an organic compound with formula . It is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings...

:

• 4,4'-diaminobiphenyl
  Benzidine
  Benzidine, the trivial name for 4,4'-diaminobiphenyl, is the solid organic compound with the formula 2. This aromatic amine is a component of a test for cyanide and also in the production of dyes...
  
  
• 1,8-diaminonaphthalene
  1,8-Diaminonaphthalene
  1,8-Diaminonaphthalene is an aromatic amine. It is a precursor to 1,8-bisnaphthalene....
  
  

External links

• Synthesis of diamines