o-Xylene

o-Xylene
Skeletal formula	Space-filling model
Names
	Preferred IUPAC name 1,2-Xylene
	Systematic IUPAC name 1,2-Dimethylbenzene
	Other names o-Xylene
Identifiers
CAS Number	95-47-6 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:28063 ;
ChEMBL	ChEMBL45005 ;
ChemSpider	6967 ;
DrugBank	DB03029 ;
ECHA InfoCard	100.002.203
KEGG	C07212 ;
RTECS number	ZE2450000;
UNII	Z2474E14QP ;
CompTox Dashboard (EPA)	DTXSID3021807 ;
	InChI InChI=1S/C8H10/c1-7-5-3-4-6-8(7)2/h3-6H,1-2H3 Key: CTQNGGLPUBDAKN-UHFFFAOYSA-N ; InChI=1/C8H10/c1-7-5-3-4-6-8(7)2/h3-6H,1-2H3 Key: CTQNGGLPUBDAKN-UHFFFAOYAE;
	SMILES CC1=C(C)C=CC=C1;
Properties
Chemical formula	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)
Solubility in water	0.02% (20°C)
Solubility in ethanol	very soluble
Solubility in diethyl ether	very soluble
Vapor pressure	7 mmHg (20°C)
Refractive index (nD)	1.50545
Viscosity	1.1049 cP at 0 °C; 0.8102 cP at 20 °C
Structure
Dipole moment	0.64 D
Hazards
NFPA 704 (fire diamond)	2 3 0
Flash point	32 °C (90 °F; 305 K)
Autoignition; temperature	463 °C (865 °F; 736 K)
Explosive limits	0.9%-6.7%
Threshold limit value (TLV)	100 ppm (TWA), 150 ppm (STEL)
	Lethal dose or concentration (LD, LC):
LCLo (lowest published)	6125 ppm (rat, 12 hr); 6125 ppm (human, 12 hr)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 100 ppm (435 mg/m3)
REL (Recommended)	TWA 100 ppm (435 mg/m3) ST 150 ppm (655 mg/m3)
IDLH (Immediate danger)	900 ppm
Safety data sheet (SDS)	External MSDS
Related compounds
Related aromatic hydrocarbons	m-xylene; p-xylene; toluene
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). verify (what is ?) Infobox references

o-Xylene (ortho-xylene) is an aromatic hydrocarbon, based on benzene with two methyl substituents bonded to adjacent carbon atoms in the aromatic ring (the ortho configuration).

It is a constitutional isomer of m-xylene and p-xylene.

o-Xylene is largely used in the production of phthalic anhydride, and is generally extracted by distillation from a mixed xylene stream in a plant primarily designed for p-xylene production.

References

^ ^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. doi:10.1016/0022-2852(73)90016-7.
^ ^a ^b ^c "o-Xylene". International Chemical Safety Cards. ICSC/NIOSH. July 1, 2014.
^ "Xylene (o-, m-, p-isomers)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).

[PGCH-1] ^ ^a ^b ^c ^d ^e ^f NIOSH Pocket Guide to Chemical Hazards. "#0668". National Institute for Occupational Safety and Health (NIOSH).

[2] 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. doi:10.1016/0022-2852(73)90016-7.

[ICSC-3] "o-Xylene". International Chemical Safety Cards. ICSC/NIOSH. July 1, 2014.

[4] "Xylene (o-, m-, p-isomers)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).

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See also

References