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p-xylene
Sign in to saveAlso known as p-xylol, paraxylene, 1,4-dimethylbenzene, 4-xylene, 4-methyltoluene, p-dimethylbenzene, para-xylene, 1,4-Dimethylbenzol
'''p-Xylene (para-xylene') is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes. The p- stands for para-, indicating that the two methyl groups in p-xylene occupy the diametrically opposite substituent positions 1 and 4. It is in the positions of the two methyl groups, their arene substitution pattern, that it differs from the other isomers, o-xylene and m-xylene. All have the same chemical formula C6H4(CH3)2. All xylene isomers are colorless and highly flammable. The odor threshold of p''-xylene is 0.62 parts per million (ppm).
Chemical data
- Formula
- C8H10
- Molecular weight
- 106.16 g/mol
- IUPAC name
- 1,4-xylene
- SMILES
- CC1=CC=C(C=C1)C
- InChIKey
- URLKBWYHVLBVBO-UHFFFAOYSA-N
- XLogP
- 3.2
- Polar surface area
- 0 Ų
- H-bond donors
- 0
- H-bond acceptors
- 0
- Formal charge
- 0
via PubChem
Wikidata facts
Show 17 more facts
- vapor pressure
- 9
- chemical formula
- C₈H₁₀
- NIOSH Pocket Guide ID
- 0670
- density
- 0.86
- immediately dangerous to life or health
- 3969
- melting point
- 13.2
- boiling point
- 138.37
- flash point
- 81
- solubility
- 0.02
- lower flammable limit
- 1.1
- upper flammable limit
- 7
- ionization energy
- 8.44
- time-weighted average exposure limit
- 435
- short-term exposure limit
- 655
- found in taxon
- Cynara cardunculus
- canonical SMILES
- CC1=CC=C(C=C1)C
- Commons category
- Para-Xylene
via Wikidata · CC0
~5 min read
Encyclopedic overview
11 sectionsContents
- Production
- Industrial applications
- Toxicity and exposure
- Inhalation
- Skin
- Eyes
- Ingestion
- Short-term exposure
- Long-term exposure
- References
- External links
'''p-Xylene (para-xylene') is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes. The p- stands for para-, indicating that the two methyl groups in p-xylene occupy the diametrically opposite substituent positions 1 and 4. It is in the positions of the two methyl groups, their arene substitution pattern, that it differs from the other isomers, o-xylene and m-xylene. All have the same chemical formula C6H4(CH3)2. All xylene isomers are colorless and highly flammable. The odor threshold of p-xylene is 0.62 parts per million (ppm).
==Production== The production of p-xylene is industrially significant, with annual demand estimated at 37 million tons in 2014, and still on the increase. p-Xylene is produced by catalytic reforming of petroleum naphtha as part of the BTX aromatics (benzene, toluene and the xylene isomers) extracted from the catalytic reformate. The p-xylene is then separated out in a series of distillation, adsorption or crystallization and reaction processes from the m-xylene, o-xylene, and ethylbenzene. Its melting point is the highest among this series of isomers, but simple crystallization does not allow easy purification due to the formation of eutectic mixtures.
Excerpted from Wikipedia’s “p-xylene” article, available under the CC BY-SA 4.0 licence.