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CAS No.: 74-39-5
Formula: C12H9N3O4
Exact Mass: 259.05900
Molecular Weight: 259.21800
PSA: 111.00000
LogP: 3.94460
Reference Price: $64/kg Post Buying Request
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Azo violet (4-(4-Nitrophenylazo)resorcinol) is an organic compound with the chemical formula C12H9N3O4. It is used commercially as a violet dye and experimentally as a pH indicator, turning blue-purple in the presence of magnesium salt in a slightly alkaline, or basic, environment. Azo violet may also be used to test for the presence of ammonium ions. The color of ammonium chloride or ammonium hydroxide solution will vary depending upon the concentration of azo violet used.
Tautomerization of Azo Violet; Azo Violet Isomerization; Azo violet is synthesized from a diazonium salt coupling reaction, from nitrophenol and resorcinol derivatives. The intense color from which the compound gets its name results from irradiation and subsequent excitation and relaxation of the extended pi electron system across the R-N=N-R’ linked phenols. Absorption of these electrons falls in the visible region of the electromagnetic spectrum. Azo violet’s intense indigo color (λmax 432 nm) approximates Pantone R: 102 G: 15 B: 240.