| | Identification | More |  | [Name] 
 Pyrocatechol Violet
 |  | [CAS] 
 115-41-3
 |  | [Synonyms] 
 3,3',4'-TRIHYDROXYFUCHSONE-2''-SULFONIC ACID
 A,A-BIS(3,4-DIHYDROXYPHENYL)-A-HYDROXY-O-TOLUENESULFONIC ACID G-SULFONE
 CATECHOLSULFONAPHTHALEIN
 CATECHOL VIOLET
 PYROCATECHOLSULFONEPHTHALEIN
 PYROCATECHOLSULFONPHTHALEIN
 PYROCATECHOL SULPHONPHTHALEIN
 PYROCATECHOL VIOLET
 1,2-Benzenediol,4,4’-(3H-2,1-benzoxathiol-3-ylidene)bis-,S,S-dioxide
 3’,3’,4’-Trihydroxyfuchsone-2’-SulfonicAcidPV
 PyrocatechinSulfonphthaleinViolet
 Pyrocatechimsulfonphthalein violed
 PYROCATECHOL VIOLET, FOR COLORIMETRY
 PYROCATECHOL VIOLET INDICATOR FOR METAL TITRATION
 PYROCATECHOL VIOLET, INDICATOR GRADE
 PyrocatecholVioletGr
 Pyrocatechol Violet, indicator grade, pure
 1,2-Benzenediol, 4,4-(1,1-dioxido-3H-2,1-benzoxathiol-3-ylidene)bis-
 Catecholsulfonphthalein
 Catechol  violet,  Pyrocatecholsulfonphthalein
 |  | [EINECS(EC#)] 
 204-088-3
 |  | [Molecular Formula] 
 C19H14O7S
 |  | [MDL Number] 
 MFCD00005868
 |  | [Molecular Weight] 
 386.38
 |  | [MOL File] 
 115-41-3.mol
 | 
 | Chemical Properties | Back Directory |  | [Appearance] 
 greenish yellow powder
 |  | [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)
 |  | [Stability:] 
 Stable. Incompatible with strong oxidizing agents.
 |  | [Water Solubility ] 
 Soluble in water, ethylene glycol, monomethyl ether and ethanol.
 |  | [BRN ] 
 353938
 |  | [CAS DataBase Reference] 
 115-41-3(CAS DataBase Reference)
 |  | [EPA Substance Registry System] 
 115-41-3(EPA Substance)
 | 
 | Safety Data | Back Directory |  | [Risk Statements ] 
 R36/37/38:Irritating to eyes, respiratory system and skin .
 |  | [Safety Statements ] 
 S24/25:Avoid contact with skin and eyes .
 |  | [WGK Germany ] 
 3
 
 |  | [TSCA ] 
 Yes
 |  | [HS Code ] 
 32041900
 | 
 | Hazard Information | Back Directory |  | [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.]
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