328251

Tetramethylammonium hydroxide solution

10 wt. % in H₂O

• Synonym(s): N,N,N-trimethyl-methanaminium hydroxide, TMAH, TMAOH
• Linear Formula: (CH₃)₄N(OH)
• CAS Number: 75-59-2
• Molecular Weight: 91.15
• Beilstein: 3558708
• MDL number: MFCD00008280
• UNSPSC Code: 12352100
• PubChem Substance ID: 24859725
• NACRES: NA.21

Properties

• vapor pressure: 17.5 mmHg ( 20 °C)
• Quality Level: 100
• concentration: 10 wt. % in H₂O
• refractive index: n20/D 1.3521
• pH: (ca.13 at 20 °C (68 °F))
• solubility: water: soluble
• density: 1.006 g/mL at 25 °C
• functional group: amine
• 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

Description

General description

Tetramethylammonium hydroxide (TMAH), is a commercially available quaternary ammonium base with significantly higher basicity than ammonium hydroxide.

Application

Tetramethylammonium hydroxide solution (10 wt. % in H₂O) can be used as:      

• A reactant to synthesize epoxy-polyhedral oligomeric silsesquioxanes (EPOSS) via sol-gel method using 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECTMS) in IPA.     
• An ionic liquid to modify SnO₂ nanocrystals, which are applicable as an efficient electron transport layer in perovskite solar cells.

TMAH can also be used as an anisotropic etchant for silicon due to its high silicon etching rate. The main advantage of using TMAH is that it causes no danger to electrical circuits due to the absence of alkali ions.

Safety Information

• Pictograms: GHS06,GHS08,GHS05
• Signal Word: Danger
• Hazard Statements: H301,H310,H314,H370,H372,H412
• Precautionary Statements: P260 - P273 - P280 - P303 + P361 + P353 - P304 + P340 + P310 - P305 + P351 + P338
• Hazard Classifications: Acute Tox. 1 Dermal - Acute Tox. 3 Oral - Aquatic Chronic 3 - Eye Dam. 1 - Skin Corr. 1B - STOT RE 1 Dermal - STOT SE 1
• Target Organs: Central nervous system, Liver,thymus
• Storage Class Code: 6.1B - Non-combustible acute toxic Cat. 1 and 2 / very toxic hazardous materials
• WGK: WGK 3
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves