Tetramethylammonium Hydroxide

Tetramethylammonium Hydroxide

CAS No.: 75-59-2
Molecular Formula: C4H13NO
Molecular Weight: 91.15
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product description
Tetramethylammonium hydroxide liquid state: Commonly, it is a colorless and transparent aqueous solution (concentration 25% - 50%). High-purity products have no impurity color, while industrial grades may be slightly light yellow. It has strong alkalinity (pH≈14) and an ammonia smell, and its viscosity increases with the increase of concentration. Solid state: White crystalline powder, with extremely strong hygroscopicity. At room temperature, it rapidly deliquesces into a viscous liquid. Therefore, it rarely exists in pure solid form and mostly in the form of hydrates (such as pentahydrate).


Chemical Properties

PropertyValue

Melting point

°C

Boiling point

110 °C

Density

0.866 g/mL at 25 °C

Vapor Pressure

17.5 mm Hg ( 20 °C)

Refractive Index

n20/D1.384

Fp

80 °F

Storage Temp.

Store below +30°C.

Solubility

Methanol (Sparingly), Water (Slightly)

Form

Solution

Color

APHA: ≤10

Odor

strong ammonia-like odor

PH

>13 (H2O, 20°C)

Water Solubility

Soluble in water.

Sensitive

Air Sensitive

Merck

14,9224

BRN

3558708

Stability:

Stable. Flammable. Incompatible with strong oxidizing agents, strong acids.

InChIKey

WGTYBPLFGIVFAS-UHFFFAOYSA-M

CAS DataBase Reference

75-59-2(CAS DataBase Reference)

EPA Substance Registry System

Tetramethylammonium hydroxide (75-59-2)


Safety Information

PropertyValue
Hazard symbolsC, T, F, Xn
Hazard class codes24/25-34-20/21/22-39/23/24/25-23/24/25-10-21/22-25-21-11-67-36-52-48/24-27/28-23-35-36/38
Safety descriptions45-36/37/39-26-16-36/37-28
UN dangerous goods number (1)UN 1835 8/PG II (TETRAMETHYLAMMONIUM HYDROXIDE AQUEOUS SOLUTION with more than 2.5% but less than 25% tetramethylammonium hydroxide)
UN dangerous goods number (2)UN 1835 8/PG III (TETRAMETHYLAMMONIUM HYDROXIDE AQUEOUS SOLUTION with not more than 2.5% tetramethylammonium hydroxide)
UN dangerous goods number (3)UN 3423 6.1/PG I (TETRAMETHYLAMMONIUM HYDROXIDE, SOLID)
WGK Germany1
RTECS numberPA0875000
F4.4-10-34
TSCATSCA listed
Hazard class3
Packing groupII
HS code29239000
Storage class3 - Flammable liquids
Hazard class (category)Acute toxicity, Category 2, Dermal
Acute toxicity, Category 2, Oral
Acute toxicity, Category 3, Inhalation
Hazardous to the aquatic environment — long-term hazard, Category 3
Serious eye damage, Category 1
Flammable liquid, Category 3
Skin corrosion, Category 1B
Specific target organ toxicity — repeated exposure, Category 1, Dermal
Specific target organ toxicity — single exposure, Category 1
Hazardous substances data75-59-2 (Hazardous Substances Data)


Product Usage
Tetramethylammonium Hydroxide (TMAH) is a strongly alkaline compound that appears as a colorless, transparent liquid. It is readily soluble in water and ethanol, possesses strong corrosive properties, and exhibits excellent catalytic activity. Its primary application lies in organic synthesis, where it serves as a strong base catalyst to accelerate reactions such as transesterification and hydrolysis. In the electronics sector, it is utilized for semiconductor wafer cleaning and photoresist stripping, thereby ensuring precision in chip manufacturing. In the chemical industry, it functions as an acid scavenger and neutralizing agent in organic synthesis, and is also employed in the preparation of quaternary ammonium salts; consequently, it stands as an indispensable key raw material across fields such as fine chemicals, electronics manufacturing, and pharmaceuticals.

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FAQ

Q1:Does it support customized products?

A1:Yes, it does. Formulations can be adjusted and customized production can be carried out according to customer's industry needs and performance parameters.


Q2:Can samples be provided?

A2:We support free sample delivery and testing services to meet customers' early testing needs.


Q3:Is the product quality stable? 

A3:With full-process quality inspection and control, there are minimal batch differences, and the purity and stability strictly meet the standards.


Q4:What is the shipping cycle?

A4:For regular inventory, we offer quick delivery. For customized orders, we arrange production according to demand and ensure timely delivery.

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