4-(4-Nitrophenylazo)resorcinol  (Synonyms: Azo Violet; Magneson I)

4-(4-Nitrophenylazo)resorcinol (Azo Violet) is an azo purple dye used experimentally as a pH indicator, showing yellow when the pH value is lower than 11 and purple when the pH value is higher than 13. In slightly alkaline or alkaline environments, it also turns dark blue in the presence of magnesium salts. Azo Violet can also be used to test for the presence of ammonium ions. The color of the ammonium chloride or ammonium hydroxide solution will change depending on the concentration of azo violet used^[1][2].

4-(4-Nitrophenylazo)resorcinol is a nitro-containing azo dye-type pH indicator that can be rapidly reduced, decolorized and degraded catalyzed by green-synthesized gold/silver nanoparticles in the presence of NaBH₄^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

259.22

C₁₂H₉N₃O₄

74-39-5

Solid

Purple to purplish red

OC1=CC=C(C(O)=C1)/N=N/C2=CC=C(C=C2)[N+]([O-])=O

Room temperature in continental US; may vary elsewhere.

4°C, protect from light

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (protect from light). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Namazi H, et al.In vitro photo-controlled drug release system based on amphiphilic linear-dendritic diblock copolymers; self-assembly behavior and application as nanocarrier. J Pharm Pharm Sci. 2011;14(2):162-80.

  [2]. Cyril N, et al. Catalytic activity of Derris trifoliata stabilized gold and silver nanoparticles in the reduction of isomers of nitrophenol and azo violet. Nano-Structures & Nano-Objects. 2020 Apr 1;22:100430.