Trihydroxybenzenes
Trihydroxybenzenes | ||||||||
Surname | 1,2,3-trihydroxybenzene | 1,2,4-trihydroxybenzene | 1,3,5-trihydroxybenzene | |||||
other names | Pyrogallol vic -Trihydroxybenzol |
Hydroxyhydroquinone asym -Trihydroxybenzol |
Phloroglucinol sym -Trihydroxybenzene |
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Structural formula | ||||||||
CAS number | 87-66-1 | 533-73-3 | 108-73-6 | |||||
PubChem | 1057 | 10787 | 359 | |||||
Molecular formula | C 6 H 6 O 3 | |||||||
Molar mass | 126.11 g mol −1 | |||||||
Physical state | firmly | |||||||
Brief description | colorless needles |
colorless to light beige solid |
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Melting point | 131-135 ° C | 140 ° C | 217-220 ° C | |||||
boiling point | 309 ° C | Decomp. | ||||||
pK s value | 9.01 | 8.45 | ||||||
solubility | 400 g / l (20 ° C) | 10 g / l (20 ° C) | ||||||
GHS labeling |
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H and P phrases | 302-312-332-341-412 | 302-315-318-335 | 315-319-335 | |||||
no EUH phrases | no EUH phrases | no EUH phrases | ||||||
273-281-302 + 352-308 + 313 | 261-280-305 + 351 + 338 | 302 + 352-305 + 351 + 338 |
The trihydroxybenzenes form a group of substances consisting of a benzene ring with three hydroxyl groups (-OH) as substituents . Their different arrangement results in three constitutional isomers with the empirical formula C 6 H 6 O 3 . They are also known by their common names pyrogallol (1,2,3-trihydroxybenzene), hydroxyhydroquinone (1,2,4-trihydroxybenzene) and phloroglucinol (1,3,5-trihydroxybenzene).
properties
1,2,3- and 1,2,4-trihydroxybenzene can be oxidized to quinones in an alkaline medium analogous to the dihydroxybenzenes with formal release of protons and electrons . With 1,3,5-trihydroxybenzene, however, the formation of a quinoid system is not possible (cf. 1,3-dihydroxybenzene ).
See also
Individual evidence
- ↑ a b c d Entry on pyrogallol in the GESTIS substance database of the IFA , accessed on April 22, 2017(JavaScript required) .
- ↑ a b data sheet 1,2,4-benzenetriol from Sigma-Aldrich , accessed on April 22, 2017 ( PDF ).
- ↑ a b c Entry on Phloroglucin in the GESTIS substance database of the IFA , accessed on April 22, 2017(JavaScript required) .
- ↑ CRC Handbook of Tables for Organic Compound Identification , Third Edition, 1984, ISBN 0-8493-0303-6 .
Web links
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