Terephthalic acid

Terephthalic acid
Names
	Preferred IUPAC name Benzene-1,4-dicarboxylic acid
	Other names Terephthalic acid; para-Phthalic acid; TPA; PTA; BDC
Identifiers
CAS Number	100-21-0 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1909333
ChEBI	CHEBI:15702 ;
ChEMBL	ChEMBL1374420;
ChemSpider	7208 ;
ECHA InfoCard	100.002.573
EC Number	202-830-0;
Gmelin Reference	50561
KEGG	C06337;
PubChem CID	7489;
RTECS number	WZ0875000;
UNII	6S7NKZ40BQ ;
CompTox Dashboard (EPA)	DTXSID6026080 ;
	InChI InChI=1S/C8H6O4/c9-7(10)5-1-2-6(4-3-5)8(11)12/h1-4H,(H,9,10)(H,11,12) Key: KKEYFWRCBNTPAC-UHFFFAOYSA-N ; InChI=1/C8H6O4/c9-7(10)5-1-2-6(4-3-5)8(11)12/h1-4H,(H,9,10)(H,11,12) Key: KKEYFWRCBNTPAC-UHFFFAOYAF;
	SMILES O=C(O)c1ccc(C(O)=O)cc1;
Properties
Chemical formula	C8H6O4
Molar mass	166.132 g·mol−1
Appearance	White crystals or powder
Density	1.519 g/cm3
Melting point	300 °C (572 °F; 573 K) Sublimes
Boiling point	Decomposes
Solubility in water	0.017 g/L at 25 °C
Solubility	polar organic solvents aqueous base
Solubility in Acetic acid	Per 100 grams; 0.035 g at 25 °C (77 °F); 0.3 g at 120 °C (248 °F); 0.75 g at 160 °C (320 °F); 1.8 g at 200 °C (392 °F); 4.5 g at 240 °C (464 °F)
Solubility in Dimethyl formamide	6.7 g per 100 g at 25 °C (77 °F)
Solubility in Dimethyl sulfoxide	20 g per 100 g at 25 °C (77 °F)
Solubility in Formic acid	0.5 g per 100 g 25 °C (77 °F)
Solubility in Methanol	Per 100 grams; 0.1 g at 25 °C (77 °F); 2.9 g at 160 °C (320 °F); 15 g at 200 °C (392 °F);
Vapor pressure	1.3 kPa (303 °C (577 °F)); 13.3 kPa (353 °C (667 °F)); 26.7 kPa (370 °C (698 °F)); 53.3 kPa (387 °C (729 °F)); 101.3 kPa (404 °C (759 °F));
Acidity (pKa)	3.54, 4.34
Magnetic susceptibility (χ)	−83.5×10−6 cm3/mol
Structure
Dipole moment	2.6D
Thermochemistry
Std enthalpy of; formation (ΔfH⦵298)	−816.1 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Flash point	260 °C (500 °F; 533 K)
Autoignition; temperature	496 °C (925 °F; 769 K)
Threshold limit value (TLV)	10 mg/m3 (STEL)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	>1 g/kg (oral, mouse)
Safety data sheet (SDS)	MSDS sheet
Related compounds
Related carboxylic acids	Phthalic acid; Isophthalic acid; Benzoic acid; p-Toluic acid
Related compounds	p-Xylene; Polyethylene terephthalate; Dimethyl terephthalate
Supplementary data page
	Terephthalic acid (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

Terephthalic acid is an organic compound with formula C₆H₄(CO₂H)₂. This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tons are produced annually. The common name is derived from the turpentine-producing tree Pistacia terebinthus and phthalic acid.

Terephthalic acid is also used in the production of PBT plastic (polybutylene terephthalate).

Names


Preferred IUPAC name Benzene-1,4-dicarboxylic acid
Other names Terephthalic acid para-Phthalic acid TPA PTA BDC
Identifiers
CAS Number	100-21-0^Y
3D model (JSmol)	Interactive image
Beilstein Reference	1909333
ChEBI	CHEBI:15702^Y
ChEMBL	ChEMBL1374420
ChemSpider	7208^Y
ECHA InfoCard	100.002.573
EC Number	202-830-0
Gmelin Reference	50561
KEGG	C06337
PubChem CID	7489
RTECS number	WZ0875000
UNII	6S7NKZ40BQ^N
CompTox Dashboard (EPA)	DTXSID6026080
InChI InChI=1S/C8H6O4/c9-7(10)5-1-2-6(4-3-5)8(11)12/h1-4H,(H,9,10)(H,11,12)^Y Key: KKEYFWRCBNTPAC-UHFFFAOYSA-N^Y InChI=1/C8H6O4/c9-7(10)5-1-2-6(4-3-5)8(11)12/h1-4H,(H,9,10)(H,11,12) Key: KKEYFWRCBNTPAC-UHFFFAOYAF
SMILES O=C(O)c1ccc(C(O)=O)cc1
Properties
Chemical formula	C₈H₆O₄
Molar mass	166.132 g·mol⁻¹
Appearance	White crystals or powder
Density	1.519 g/cm³^: 3.492
Melting point	300 °C (572 °F; 573 K) Sublimes^: 3.492
Boiling point	Decomposes
Solubility in water	0.017 g/L at 25 °C^: 5.163
Solubility	polar organic solvents aqueous base
Solubility in Acetic acid	Per 100 grams 0.035 g at 25 °C (77 °F) 0.3 g at 120 °C (248 °F) 0.75 g at 160 °C (320 °F) 1.8 g at 200 °C (392 °F) 4.5 g at 240 °C (464 °F)
Solubility in Dimethyl formamide	6.7 g per 100 g at 25 °C (77 °F)
Solubility in Dimethyl sulfoxide	20 g per 100 g at 25 °C (77 °F)
Solubility in Formic acid	0.5 g per 100 g 25 °C (77 °F)
Solubility in Methanol	Per 100 grams 0.1 g at 25 °C (77 °F) 2.9 g at 160 °C (320 °F) 15 g at 200 °C (392 °F)
Vapor pressure	1.3 kPa (303 °C (577 °F)) 13.3 kPa (353 °C (667 °F)) 26.7 kPa (370 °C (698 °F)) 53.3 kPa (387 °C (729 °F)) 101.3 kPa (404 °C (759 °F))
Acidity (pK_a)	3.54, 4.34^: 5.96
Magnetic susceptibility (χ)	−83.5×10⁻⁶ cm³/mol^: 3.579
Structure
Dipole moment	2.6D
Thermochemistry^: 5.37
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	−816.1 kJ/mol
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Flash point	260 °C (500 °F; 533 K)^: 16.29
Autoignition temperature	496 °C (925 °F; 769 K)^: 16.29
Threshold limit value (TLV)	10 mg/m³^: 16.42 (STEL)
Lethal dose or concentration (LD, LC):
LD₅₀ (median dose)	>1 g/kg (oral, mouse)
Safety data sheet (SDS)	MSDS sheet
Related compounds
Related carboxylic acids	Phthalic acid Isophthalic acid Benzoic acid p-Toluic acid
Related compounds	p-Xylene Polyethylene terephthalate Dimethyl terephthalate
Supplementary data page
Terephthalic acid (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references