1,2,3-Trimethylbenzene

1,2,3-Trimethylbenzene
Names
Preferred IUPAC name
1,2,3-Trimethylbenzene
Other names
Hemellitol; Hemimellitol, Hemimelithol; Hemimellitine; Hemimellitene
Identifiers
CAS Number
3D model (JSmol)
Beilstein Reference
1903410
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.007.633
EC Number
  • 208-394-8
Gmelin Reference
326517
PubChem CID
RTECS number
  • DC3300000
UNII
UN number 1993
CompTox Dashboard (EPA)
InChI
  • InChI=1S/C9H12/c1-7-5-4-6-8(2)9(7)3/h4-6H,1-3H3 checkY
    Key: FYGHSUNMUKGBRK-UHFFFAOYSA-N checkY
  • InChI=1S/C9H12/c1-7-5-4-6-8(2)9(7)3/h4-6H,1-3H3
SMILES
  • c1(cccc(c1C)C)C
Properties
Chemical formula
C9H12
Molar mass 120.195 g·mol−1
Appearance Colorless liquid[1]
Density 0.89 g/mL[1]
Melting point −25 °C (−13 °F; 248 K)[1]
Boiling point 176 °C (349 °F; 449 K)[1]
Solubility in water
0.006% (20°C)[2]
Vapor pressure 1 mmHg (16.7°C)[2]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Flammable[3]
GHS labelling:
Pictograms
GHS02: FlammableGHS07: Exclamation markGHS08: Health hazard
Signal word
Warning
Hazard statements
H226, H315, H319, H335
Precautionary statements
P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
Flash point 11 °C; 51 °F; 284 K[1]
Autoignition
temperature
243 °C; 470 °F; 516 K[1]
Explosive limits 0.8%-6.6%[2]
NIOSH (US health exposure limits):
PEL (Permissible)
none[2]
REL (Recommended)
TWA 25 ppm (125 mg/m3)[2]
IDLH (Immediate danger)
N.D.[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

1,2,3-Trimethylbenzene is an organic compound with the chemical formula C6H3(CH3)3. Classified as an aromatic hydrocarbon, it is a flammable colorless liquid. It is nearly insoluble in water but soluble in organic solvents.

The compound occurs naturally in coal tar and petroleum. It is one of the three isomers of trimethylbenzene. It is used in jet fuel, mixed with other hydrocarbons, to prevent the formation of solid particles which might damage the engine.

German chemist Oscar Jacobsen first prepared the hydrocarbon in 1882 and designated it hemellitol as a reference to the trivial name of hexamethylbenzene.[4] Four years later he also discovered it in the coal tar.[5]

Production

Industrially, it is isolated from the C9 aromatic hydrocarbon fraction during petroleum distillation. It is also generated by methylation of toluene and xylenes.[6]

References

  1. ^ a b c d e f Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. ^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0637". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ CDC - NIOSH Pocket Guide to Chemical Hazards
  4. ^ Jacobsen, Oscar (1882). "Ueber Isodurol, Isodurylsäuren und das dritte Trimethylbenzol". Berichte der deutschen chemischen Gesellschaft. 15 (2): 1853–1858. doi:10.1002/cber.18820150292. ISSN 0365-9496.
  5. ^ Jacobsen, Oscar (1886). "Beitrag zur Kenntniss der zwischen 170 und 200° siedenden Kohlenwasserstoffe des Steinkohlentheeröls". Berichte der deutschen chemischen Gesellschaft. 19 (2): 2511–2515. doi:10.1002/cber.188601902195. ISSN 0365-9496.
  6. ^ Karl Griesbaum, Arno Behr, Dieter Biedenkapp, Heinz-Werner Voges, Dorothea Garbe, Christian Paetz, Gerd Collin, Dieter Mayer, Hartmut Höke "Hydrocarbons" in Ullmann's Encyclopedia of Industrial Chemistry 2002 Wiley-VCH, Weinheim. doi:10.1002/14356007.a13_227