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| Names | |||
|---|---|---|---|
| Preferred IUPAC name 1,2-Xylene[1] | |||
| Systematic IUPAC name 1,2-Dimethylbenzene[1] | |||
| Other names o-Xylene,[1] o-Xylol | |||
| Identifiers | |||
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3D model (JSmol) | |||
| 1815558 | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider |
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| DrugBank |
| ||
| ECHA InfoCard | 100.002.203 | ||
| EC Number |
| ||
| 67796 | |||
| KEGG |
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| RTECS number |
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| UNII | |||
| UN number | 1307 | ||
| |||
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| Properties | |||
| C8H10 | |||
| 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 inethanol | very soluble | ||
| Solubility indiethyl ether | very soluble | ||
| Vapor pressure | 7 mmHg (20°C)[2] | ||
| −77.78·10−6 cm3/mol | |||
Refractive index (nD) | 1.50545 | ||
| Viscosity | 1.1049 cP at 0 °C 0.8102 cP at 20 °C | ||
| Structure | |||
| 0.64D[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] | ||
Threshold limit value (TLV) | 100 ppm[4] (TWA), 150 ppm[4] (STEL) | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose) | 4300 mg/kg (rats,orally)[5] | ||
LCLo (lowest published) | 6125 ppm (rat, 12 hr) 6125 ppm (human, 12 hr)[6] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) | TWA 100 ppm (435 mg/m3)[2] | ||
REL (Recommended) | TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3)[2] | ||
IDLH (Immediate danger) | 900 ppm[2] | ||
| Safety data sheet (SDS) | External MSDS | ||
| Related compounds | |||
Relatedaromatic hydrocarbons | m-xylene p-xylene toluene | ||
| Supplementary data page | |||
| O-Xylene (data page) | |||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
o-Xylene (ortho-xylene) is anaromatic hydrocarbon with theformula C6H4(CH3)2, with twomethylsubstituents bonded to adjacent carbonatoms of abenzenering (theortho configuration). It is aconstitutional isomer ofm-xylene andp-xylene, the mixture being calledxylene or xylenes.o-Xylene is acolourless slightlyoily flammableliquid.[7]
Petroleum contains about one weight percent xylenes. Mosto-xylene is produced by crackingpetroleum, which affords a distribution of aromatic compounds, including xylene isomers.m-Xylene is isomerized too-xylene. Net production was approximately 500,000 tons in the year 2000.
o-Xylene is largely used in the production ofphthalic 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 elementalbromine, these groups are brominated, yieldingxylylene dibromide:[8]
Xylenes are not acutely toxic, for example theLD50 (rat, oral) is 4300 mg/kg. Effects vary with animal and xylene isomer. Concerns with xylenes focus on narcotic effects.[7]
