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Names | |||
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Preferred IUPAC name
Aniline
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Systematic IUPAC name
Benzenamine
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Other names
Phenylamine
Aminobenzene Benzamine |
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Identifiers | |||
3D model (JSmol)
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ChEBI | |||
ChemSpider | |||
DrugBank | |||
ECHA InfoCard | 100.000.491 | ||
KEGG | |||
PubChem CID
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UNII | |||
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Properties | |||
C6H7N | |||
Molar mass | 93.13 g·mol−1 | ||
Appearance | Colorless to yellow liquid | ||
Density | 1.0217 g/mL | ||
Melting point | −6.3 °C (20.7 °F; 266.8 K) | ||
Boiling point | 184.13 °C (363.43 °F; 457.28 K) | ||
3.6 g/100 mL at 20 °C | |||
Vapor pressure | 0.6 mmHg (20° C) | ||
Acidity (pKa) | 4.6 (for the conjugate acid) | ||
Basicity (pKb) | 9.4 | ||
-62.95·10−6 cm3/mol | |||
Viscosity | 3.71 cP (3.71 mPa·s at 25 °C) | ||
Thermochemistry | |||
Std enthalpy of
combustion (ΔcH |
-3394 kJ/mol | ||
Hazards | |||
Main hazards | potential occupational carcinogen | ||
Safety data sheet | See: data page | ||
EU classification (DSD) (outdated)
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T N | ||
R-phrases (outdated) | R23/24/25 R40 R41 R43 R48/23/24/25 R68 R50 | ||
S-phrases (outdated) | (S1/2) S26 S27 S36/37/39 S45 S46 S61 S63 | ||
NFPA 704 | |||
Flash point | 70 °C (158 °F; 343 K) | ||
770 °C (1,420 °F; 1,040 K) | |||
Explosive limits | 1.3%-11% | ||
Lethal dose or concentration (LD, LC): | |||
LDLo (lowest published)
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195 mg/kg (dog, oral) 250 mg/kg (rat, oral) 464 mg/kg (mouse, oral) 440 mg/kg (rat, oral) 400 mg/kg (guinea pig, oral) |
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LC50 (median concentration)
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175 ppm (mouse, 7 hr) | ||
LCLo (lowest published)
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250 ppm (rat, 4 hr) 180 ppm (cat, 8 hr) |
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US health exposure limits (NIOSH): | |||
PEL (Permissible)
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TWA 5 ppm (19 mg/m3) [skin] | ||
REL (Recommended)
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Ca [potential occupational carcinogen] | ||
IDLH (Immediate danger)
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100 ppm | ||
Related compounds | |||
Related aromatic amines
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1-Naphthylamine 2-Naphthylamine |
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Related compounds
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Phenylhydrazine Nitrosobenzene Nitrobenzene |
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Supplementary data page | |||
Refractive index (n), Dielectric constant (εr), etc. |
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Thermodynamic
data |
Phase behaviour solid–liquid–gas |
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UV, IR, NMR, MS | |||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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what is ?) | (|||
Infobox references | |||
Aniline is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. Its main use is in the manufacture of precursors to polyurethane and other industrial chemicals. Like most volatile amines, it possesses the odour of rotten fish. It ignites readily, burning with a smoky flame characteristic of aromatic compounds.
Aniline is a planar molecule. The amine is nearly planar owing to conjugation of the lone pair with the aryl substituent. The C-N distance is correspondingly shorter. In aniline, the C-N and C-C distances are close to 1.39 Å, indicating the π-bonding between N and C.
Industrial aniline production involves two steps. First, benzene is nitrated with a concentrated mixture of nitric acid and sulfuric acid at 50 to 60 °C to yield nitrobenzene. The nitrobenzene is then hydrogenated (typically at 200–300 °C) in the presence of metal catalysts.
The reduction of nitrobenzene to aniline was first performed by Nikolay Zinin in 1842 using inorganic sulfide as a reductant (Zinin reaction).
Aniline can alternatively be prepared from ammonia and phenol derived from the cumene process.
In commerce, three brands of aniline are distinguished: aniline oil for blue, which is pure aniline; aniline oil for red, a mixture of equimolecular quantities of aniline and ortho- and para-toluidines; and aniline oil for safranine, which contains aniline and ortho-toluidine, and is obtained from the distillate (échappés) of the fuchsine fusion.