O-Xylene
o -Xylene
Skeletal formula
Space-filling model
Names
Preferred IUPAC name
Systematic IUPAC name
Other names
Identifiers
1815558
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard
100.002.203
EC Number
67796
KEGG
RTECS number
UNII
UN number
1307
InChI=1S/C8H10/c1-7-5-3-4-6-8(7)2/h3-6H,1-2H3
Y Key: CTQNGGLPUBDAKN-UHFFFAOYSA-N
Y InChI=1/C8H10/c1-7-5-3-4-6-8(7)2/h3-6H,1-2H3
Key: CTQNGGLPUBDAKN-UHFFFAOYAE
Properties
C 8 H 10
Molar mass
106.168 g·mol−1
Appearance
Colorless liquid
Density
0.88 g/ml
Melting point
−24 °C (−11 °F; 249 K)
Boiling point
144.4 °C (291.9 °F; 417.5 K)
0.02% (20°C)[2]
Solubility in ethanol
very soluble
Solubility in diethyl ether
very soluble
Vapor pressure
7 mmHg (20°C)[2]
-77.78·10−6 cm3 /mol
1.50545
Viscosity
1.1049 cP at 0 °C 0.8102 cP at 20 °C
Structure
0.64 D [3]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Mildly toxic
GHS labelling :
Danger
H225 , H226 , H304 , H305 , H312 , H315 , H319 , H332 , H335 , H412
P210 , P233 , P240 , P241 , P242 , P243 , P261 , P264 , P271 , P273 , P280 , P301+P310 , P302+P352 , P303+P361+P353 , P304+P312 , P304+P340 , P305+P351+P338 , P312 , P321 , P322 , P331 , P332+P313 , P337+P313 , P362 , P363 , P370+P378 , P403+P233 , P403+P235 , P405 , P501
NFPA 704 (fire diamond)
Flash point
32 °C (90 °F; 305 K)
463 °C (865 °F; 736 K)[4]
Explosive limits
0.9%-6.7%[2]
100 ppm[4] (TWA), 150 ppm[4] (STEL)
Lethal dose or concentration (LD, LC):
4300 mg/kg (rats, orally )[5]
6125 ppm (rat, 12 hr) 6125 ppm (human, 12 hr)[6]
NIOSH (US health exposure limits):
TWA 100 ppm (435 mg/m3 )[2]
TWA 100 ppm (435 mg/m3 ) ST 150 ppm (655 mg/m3 )[2]
900 ppm[2]
Safety data sheet (SDS)
External MSDS
Related compounds
m -xylenep -xylenetoluene
Supplementary data page
O-Xylene (data page)
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
Chemical compound
o -Xylene (ortho -xylene ) is an aromatic hydrocarbon with the formula C6 H4 (CH3 )2 , with two methyl substituents bonded to adjacent carbon atoms of a benzene ring (the ortho configuration). It is a constitutional isomer of m -xylene and p -xylene , the mixture being called xylene or xylenes. o -Xylene is a colourless slightly oily flammable liquid .[7]
Production and use
Petroleum contains about one weight percent xylenes. Most o -xylene is produced by cracking petroleum , which affords a distribution of aromatic compounds, including xylene isomers. m -Xylene is isomerized to o -xylene. Net production was approximately 500,000 tons in the year 2000.
o -Xylene is largely used in the production of phthalic anhydride , which is a precursor to many materials, drugs, and other chemicals.[7] Related to their easy oxidation, the methyl groups are susceptible to halogenation. When treated with elemental bromine , these groups are brominated, yielding xylylene dibromide :[8]
C6 H4 (CH3 )2 + 2 Br2 → C6 H4 (CH2 Br)2 + 2 HBr
Toxicity and exposure
Xylenes are not acutely toxic, for example the LD50 (rat, oral) is 4300 mg/kg. Effects vary with animal and xylene isomer. Concerns with xylenes focus on narcotic effects.[7]
References
^ a b c Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) . Cambridge: The Royal Society of Chemistry . 2014. pp. 121, 139, 653. doi :10.1039/9781849733069 . ISBN 978-0-85404-182-4 .
^ a b c d e f NIOSH Pocket Guide to Chemical Hazards. "#0668" . National Institute for Occupational Safety and Health (NIOSH).
^ Rudolph, H.D.; Walzer, K.; Krutzik, Irmhild (1973). "Microwave spectrum, barrier for methyl rotation, methyl conformation, and dipole moment of ortho-xylene". Journal of Molecular Spectroscopy . 47 (2): 314. Bibcode :1973JMoSp..47..314R . doi :10.1016/0022-2852(73)90016-7 .
^ a b c "o-Xylene" . International Chemical Safety Cards . ICSC/NIOSH. July 1, 2014.
^ O-xylene toxicity
^ "Xylene (o-, m-, p-isomers)" . Immediately Dangerous to Life or Health Concentrations (IDLH) . National Institute for Occupational Safety and Health (NIOSH).
^ a b c Fabri, Jörg; Graeser, Ulrich; Simo, Thomas A. (2000). "Xylenes". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi :10.1002/14356007.a28_433 . ISBN 978-3527306732 .
^ Emily F. M. Stephenson (1954). "o-Xylylene Dibromide". Organic Syntheses . 34 : 100. doi :10.15227/orgsyn.034.0100 .