M-Xylene

m-Xylene

Names
Preferred IUPAC name 1,3-Xylene
Systematic IUPAC name 1,3-Dimethylbenzene
Other names m-Xylene
Identifiers
CAS Number	108-38-3 Y
3D model (Jmol)	Interactive image Interactive image
ChEBI	CHEBI:28488 N
ChEMBL	ChEMBL286727 N
ChemSpider	7641 Y
ECHA InfoCard	100.003.252
KEGG	C07208 N
PubChem	7929
RTECS number	ZE2275000
UNII	O9XS864HTE N
InChI InChI=1S/C8H10/c1-7-4-3-5-8(2)6-7/h3-6H,1-2H3 Y Key: IVSZLXZYQVIEFR-UHFFFAOYSA-N Y
SMILES Cc1cccc(c1)C CC1=CC(C)=CC=C1
Properties
Chemical formula	C8H10
Molar mass	106.16 g/mol
Appearance	Colorless liquid
Density	0.86 g/mL
Melting point	−48 °C (−54 °F; 225 K)
Boiling point	139 °C (282 °F; 412 K)
Solubility in water	insoluble
Solubility in ethanol	very soluble
Solubility in diethyl ether	very soluble
Vapor pressure	9 mmHg (20°C)
Magnetic susceptibility (χ)	-76.56·10−6 cm3/mol
Refractive index (nD)	1.49722
Viscosity	0.8059 cP at 0 °C 0.6200 cP at 20 °C
Dipole moment	0.33-0.37 D
Hazards
Main hazards	Harmful or fatal if swallowed. Vapor harmful. Flammable liquid and vapor.
Safety data sheet	See: data page External MSDS
R-phrases	R10 R20 R21 R38
S-phrases	S25
NFPA 704	3 1 0
Flash point	27 °C (81 °F; 300 K)
Autoignition temperature	527 °C (981 °F; 800 K)
Explosive limits	1.1%-7.0%
Threshold limit value	100 ppm (TWA), 150 ppm (STEL)
Lethal dose or concentration (LD, LC):
LCLo (lowest published)	2010 ppm (mouse, 24 hr) 8000 ppm (rat, 4 hr)
US health exposure limits (NIOSH):
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
Related compounds
Related aromatic hydrocarbons	benzene toluene o-xylene p-xylene
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

m-Xylene (or meta-xylene) is an aromatic hydrocarbon, based on benzene with two methyl substituents. It is an isomer of o-xylene and p-xylene. The m stands for meta, meaning the two methyl substituents are at locants 1 and 3 on the aromatic ring. m-Xylene is commonly produced in BTX processes, and separated as needed from the other aromatic hydrocarbons.

The major chemical use of meta-xylene is in the manufacture of isophthalic acid, which is used as a copolymerizing monomer to alter the properties of polyethylene terephthalate (PET), making PET more suitable for the manufacture of soft drinks bottles. To convert m-xylene on an industrial scale to isophthalic acid, the two methyl groups are both catalytically oxidized to carboxyl groups. It is also used as a raw material in the manufacture of 2,4- and 2,6-xylidine as well as a range of smaller-volume chemicals.