Tetramethylammonium hydroxide
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| General | ||||||||||
| Surname | Tetramethylammonium hydroxide | |||||||||
| Molecular formula | C 4 H 13 NO | |||||||||
| Brief description |
colorless, deliquescent needles that smell strongly like ammonia |
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| properties | ||||||||||
| Molar mass | 91.15 g mol −1 | |||||||||
| Physical state |
firmly |
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| Melting point |
67-70 ° C |
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| Vapor pressure |
129 h Pa (20 ° C) |
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| solubility |
easily in water (700 g · l −1 at 20 ° C) to form strongly basic solutions |
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| safety instructions | ||||||||||
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| Toxicological data |
25 mg · kg -1 ( LD 50 , guinea pigs , sc ) |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||
Tetramethylammonium hydroxide ( TMAH ) is a quaternary ammonium compound with the constitutional formula [N (CH 3 ) 4 ] OH, ionic [N (CH 3 ) 4 ] + OH - .
properties
Chemical properties
TMAH is a strong base . When TMAH is heated, it decomposes into trimethylamine and methanol .
use
- In semiconductor production with anisotropic etching of silicon
- As a solvent when developing acidic photoresists
- To prevent the nanoparticles from agglomerating in a ferrofluid
- As a derivatization reagent (formation of methyl derivatives) in chemical analysis
- As a template for the production of synthetic zeolites
safety instructions
TMAH causes severe irritation up to and including chemical burns to the eyes, airways, lungs and skin.
The tetramethylammonium cation (TMA) can damage nerves and muscles, which can lead to respiratory paralysis and ultimately death within a very short time.
Individual evidence
- ↑ a b c Entry on tetramethylammonium salts. In: Römpp Online . Georg Thieme Verlag, accessed on December 28, 2014.
- ↑ a b c d e Entry on tetramethylammonium hydroxide in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
- ↑ Entry on tetramethylammonium hydroxide in the ChemIDplus database of the United States National Library of Medicine (NLM)
- ↑ Wu, CL et al. (2008): Mortality from dermal exposure to tetramethylammonium hydroxide. In: J. Occup. Health. 50 (2): 99-102. PMID 18403859 .