Pyrocatechol Violet Chemical Properties

Melting point:

185 °C (dec.)(lit.)

Boiling point:

659.5±55.0 °C(Predicted)

Density 

1.632±0.06 g/cm3(Predicted)

storage temp. 

-20°C Freezer, Under inert atmosphere

solubility 

H₂O: 1 mg/mL, clear, red

form 

Metallic or Crystalline Powder

pka

7.21±0.10(Predicted)

color 

Dark red-brown

PH Range

6.0(YELLOW)-7.0(PURPLE)-9.0(PURPLISH RED)

Water Solubility 

Soluble in water, ethylene glycol, monomethyl ether and ethanol.

BRN 

353938

Stability:

Stable. Incompatible with strong oxidizing agents.

CAS DataBase Reference

115-41-3(CAS DataBase Reference)

EPA Substance Registry System

1,2-Benzenediol, 4,4'-(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis- (115-41-3)

Safety Information

Risk Statements 

36/37/38

Safety Statements 

24/25

WGK Germany 

3

TSCA 

Yes

HS Code 

32041900

MSDS

• Language:English Provider:Catecholsulfonphthalein
• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

Pyrocatechol Violet Usage And Synthesis

Chemical Properties

greenish yellow powder

Uses

A complexometric indicator.

Uses

Pyrocatechol Violet is a complexometric indicator dye. This phthalein dye chelates metals to form blue to blue-violet complexs. It is also a pH indicator with a transition interval from 0 - 8 (red to violet). It is known to be unstable when alkaline. The stability is improved at a neutral pH. When the pH is between 2-7 the color may be yellow. Dyes and metabolites.

Purification Methods

It is recrystallised from glacial acetic acid. It is very hygroscopic and is an indicator standard for metal complex titrations. [Mustafin et al. Zh Anal Khim 22 1808 1967, Beilstein 19/3 V 703.]

Pyrocatechol Violet(115-41-3)Related Product Information

• Catechol
• 4-Fluorocatechol
• Dibutyl phthalate
• 4-tert-Butylcatechol
• CATECHOLBORANE
• 1,2-Dimethoxybenzene
• Phthalic acid
• o-Phthalaldehyde
• Phthalic anhydride
• 2-Ethylbenzenethiol
• PYROGALLOL RED
• ISOPROPYL METHANESULFONATE
• Methyl benzenesulfonate
• Bromopyrogallol Red
• 4,4'-DIHYDROXYDIPHENYLMETHANE
• 2-MERCAPTOBENZYL ALCOHOL
• 4-Isopropylphenol
• 2-PHENYL-2-PROPANOL
• Catechol Violet