Aurine (dye)
Structural formula | ||||||||||||||||
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General | ||||||||||||||||
Surname | Aurin | |||||||||||||||
other names |
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Molecular formula | C 19 H 14 O 3 | |||||||||||||||
Brief description |
red-brown solid |
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properties | ||||||||||||||||
Molar mass | 290.32 g · mol -1 | |||||||||||||||
Physical state |
firmly |
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solubility |
almost insoluble in water, soluble in acids and alkali solutions |
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safety instructions | ||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Aurin is a triphenylmethane dye that is used as a pH indicator .
Appearance and properties
Aurine is formed when phenol is heated with oxalic acid in concentrated sulfuric acid , the latter acting as a condensation and oxidizing agent:
The yellow-brown or red substance dissolves in alkalis, fuchsin-red, where it serves as a pH indicator. The sodium salt is used to dye wallpaper and paper. The absorption maximum is at λ = 482 nm.
literature
- Paul Karrer: Textbook of Organic Chemistry , 10th Edition, Georg Thieme Verlag, Stuttgart 1948, p. 643.
Individual evidence
- ↑ Data Aurin (dye) from Acros, accessed on 23 February 2010 .
- ↑ Hach-Lange.de: MSDS Rosolic Acid ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (accessed August 11, 2012).
- ↑ a b c Data sheet Aurin (dye) from Sigma-Aldrich , accessed on March 9, 2011 ( PDF ).
- ↑ S. Hauptmann , J. Graefe, H. Remane : Textbook of Organic Chemistry, VEB Deutscher Verlag für Grundstoffindustrie, Leipzig 1980, p. 694.