| Title:  2,6-Dichloroindophenol Sodium CAS Registry Number:  620-45-1 CAS Name:  2,6-Dichloro-4-[(4-hydroxyphenyl)imino]-2,5-cyclohexadien-1-one sodium salt Additional Names:  sodium 2,6-dichloroindophenol;  sodium 2,6-dichloro-N-(p-hydroxyphenyl)-p-benzoquinone imine;  2,6-dichloro-1,4-benzoquinone-4-(4-hydroxyanil) sodium;  2,6-dichlorophenol-indophenol sodium;  Tillman's reagent Molecular Formula:  C12H6Cl2NNaO2 Molecular Weight:  290.08 Percent Composition:  C 49.69%, H 2.08%, Cl 24.44%, N 4.83%, Na 7.93%, O 11.03% Literature References:  Prepd from 2,6-dichloro-p-quinone-4-chlorimide and phenol in alkaline soln:  Gibbs et al., Public Health Rep. 40, 650 (1925); Tillmans et al., Z. Unters. Lebensm. 56, 273 (1932). Properties:  Dark green powder.  May contain up to 2 mols H2O.  Freely sol in water, alc.  The aq soln is deep blue, changed to red by acids.  It liberates iodine from KI in acid solns. Use:  Analytical reagent in the determination of ascorbic acid (vitamin C) which reduces the dye to a colorless hydroxy compd.  |