Aluminon

Aluminon

Names
Other names ammonium aurin-tricarboxylate; 5-[(3-carboxy-4-hydroxyphenyl)(3-carboxy-4-oxo-2,5-cyclohexadien-ylidene)methyl]-2-hydroxybenzoic acid triammonium salt
Identifiers
CAS Number	569-58-4
ChemSpider	2016698
Jmol interactive 3D	Image
PubChem	2734958
InChI InChI=1S/C22H14O9.3H3N/c23-16-4-1-10(7-13(16)20(26)27)19(11-2-5-17(24)14(8-11)21(28)29)12-3-6-18(25)15(9-12)22(30)31;;;/h1-9,23-24H,(H,26,27)(H,28,29)(H,30,31);3*1H3 Key: AIPNSHNRCQOTRI-UHFFFAOYSA-N InChI=1/C22H14O9.3H3N/c23-16-4-1-10(7-13(16)20(26)27)19(11-2-5-17(24)14(8-11)21(28)29)12-3-6-18(25)15(9-12)22(30)31;;;/h1-9,23-24H,(H,26,27)(H,28,29)(H,30,31);3*1H3 Key: AIPNSHNRCQOTRI-UHFFFAOYAI
SMILES O=C([O-])\C1=C\C(\C=C/C1=O)=C(\c2ccc(O)c(C([O-])=O)c2)c3ccc(O)c(C([O-])=O)c3.[NH4+].[NH4+].[NH4+]
Properties
Chemical formula	C22H23N3O9
Molar mass	473.43 g/mol
Appearance	yellow-brown crystals, red in aqueous solution
Solubility in other solvents	freely soluble in H2O
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Aluminon, the triammonium salt of aurintricarboxylic acid, is a dye commonly used to detect the presence of the aluminium ion in an aqueous solution. In addition to its use in qualitative inorganic analysis, aluminon has applications in pigment production. It forms brilliantly colored lake pigments with aluminum, chromium, iron, and beryllium.

Aluminon is prepared by reacting sodium nitrite with salicylic acid, adding formaldehyde, then treating with ammonia.^[1]

See also

• Analytical chemistry
• Colorimetry

References

1. Merck Index, 13th Ed.