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 ;
3D model (JSmol)	Interactive image;
ChemSpider	2016698 ;
ECHA InfoCard	100.008.473
EC Number	209-319-1;
PubChem CID	54729869;
UNII	23J05NR06D ;
CompTox Dashboard (EPA)	DTXSID40932215 DTXSID20889354, DTXSID40932215 ;
	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);31H3 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);31H3 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
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319
Precautionary statements	P264, P280, P302+P352, P305+P351+P338, P321, P332+P313, P337+P313, P362
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Aluminon, the triammonium salt of aurintricarboxylic acid, is a dye often used to detect the presence of the aluminium ion in an aqueous solution. Aluminon forms a red complex salt in combination with Al³⁺.^[1]

In addition to its use in qualitative inorganic analysis, aluminon has applications in pigment production. It forms brilliantly colored lake pigments with many metals. The pigments are red in combination with Be²⁺ and Ga³⁺. The pigment is deep purple or reddish-brown in combination with Fe³⁺. Color of a particular pigment in acidic solutions may change: aluminon and Sc³⁺ form red pigments if the solution is acidic, but otherwise the solutions are colorless.^[1]

Aluminon is prepared by reacting sodium nitrite with salicylic acid, adding formaldehyde, then treating with ammonia.^[2]

References

^ ^a ^b Clark, RA; Krueger, GL (1985). "Aluminon: its limited application as a reagent for the detection of aluminum species". Journal of Histochemistry & Cytochemistry. 33 (7): 729–732. doi:10.1177/33.7.3891845. ISSN 0022-1554. PMID 3891845.
^ Merck Index, 13th Ed.

[:0-1] Clark, RA; Krueger, GL (1985). "Aluminon: its limited application as a reagent for the detection of aluminum species". Journal of Histochemistry & Cytochemistry. 33 (7): 729–732. doi:10.1177/33.7.3891845. ISSN 0022-1554. PMID 3891845.

[2] Merck Index, 13th Ed.

[1]

[2]

See also

References