1,2,3-Trimethylbenzene

(Redirected from Hemimellitene)

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. It 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.

1,2,3-Trimethylbenzene
Names
Preferred IUPAC name
1,2,3-Trimethylbenzene
Other names
Hemellitol; Hemimellitol, Hemimelithol; Hemimellitine; Hemimellitene
Identifiers
3D model (JSmol)
1903410
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.007.633 Edit this at Wikidata
EC Number
  • 208-394-8
326517
RTECS number
  • DC3300000
UNII
UN number 1993
  • 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
  • c1(cccc(c1C)C)C
Properties
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]
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:
GHS02: FlammableGHS07: Exclamation markGHS08: Health hazard
Warning
H226, H315, H319, H335
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]
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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Production and uses

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Industrially, it is isolated from the C9 aromatic hydrocarbon fraction during petroleum distillation. It is also generated by methylation of toluene and xylenes.[4]

References

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  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. ^ 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