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334901

Sigma-Aldrich

Tetramethylammonium hydroxide solution

25 wt. % in methanol

Synonym(s):

N,N,N-trimethyl-methanaminium hydroxide, TMAH, TMAOH

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About This Item

Linear Formula:
(CH3)4N(OH)
CAS Number:
Molecular Weight:
91.15
Beilstein:
3558708
MDL number:
UNSPSC Code:
12352100
PubChem Substance ID:
NACRES:
NA.21

vapor pressure

17.5 mmHg ( 20 °C)

Quality Level

form

liquid

concentration

25 wt. % in methanol

impurities

≤10% water
≤2% chloride

density

0.866 g/mL at 25 °C

SMILES string

[OH-].C[N+](C)(C)C

InChI

1S/C4H12N.H2O/c1-5(2,3)4;/h1-4H3;1H2/q+1;/p-1

InChI key

WGTYBPLFGIVFAS-UHFFFAOYSA-M

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General description

Tetramethylammonium hydroxide is a strong base used in the o-alkylation of phenolic and carboxylic OH groups.

Tetramethylammonium hydroxide is a quaternary ammonium salt generally used as an anisotropic etchant for silicon due to its high silicon etching rate.

Application

Tetramethylammonium hydroxide solution (25 wt.% solution in methanol) may be used in the synthesis of zirconium oxides via a modified sol-gel method with potential application as catalyst materials in CO hydrogenation.

Signal Word

Danger

Hazard Classifications

Acute Tox. 2 Dermal - Acute Tox. 2 Oral - Acute Tox. 3 Inhalation - Aquatic Chronic 3 - Eye Dam. 1 - Flam. Liq. 3 - Skin Corr. 1B - STOT RE 1 Dermal - STOT SE 1

Target Organs

Eyes,Central nervous system, Liver,thymus

Storage Class Code

3 - Flammable liquids

WGK

WGK 3

Flash Point(F)

80.6 °F - closed cup

Flash Point(C)

27 °C - closed cup

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

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Amy J Williams et al.
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The Mars Curiosity rover carries a diverse instrument payload to characterize habitable environments in the sedimentary layers of Aeolis Mons. One of these instruments is Sample Analysis at Mars (SAM), which contains a mass spectrometer that is capable of detecting
Characterization of Zirconia-based catalysts prepared by precipitation, calcination, and modified sol-gel methods.
Feng Z, et al.
Industrial & Engineering Chemistry Research, 34(1), 78-82 (1995)
Quantitative Methylation of Lignin Monomers Using Tetrabutylammonium Hydroxide and MeI and Applications in Organic Synthesis
Zuo Y, et al.
ACS Omega, 8, 7057-7062 (2023)
Study on anisotropic silicon etching characteristics in various surfactant-added tetramethyl ammonium hydroxide water solutions.
Yang CR, et al.
Journal of Micromechanics and Microengineering, 15(11), 2028-2028 (2005)
The characteristic behavior of TMAH water solution for anisotropic etching on both silicon substrate and SiO 2 layer.
Chen PH, et al.
Sensors and actuators A, Physical, 93(2), 132-137 (2001)

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