Tetramethylammonium hydroxide

Tetramethylammonium hydroxide

Names
IUPAC name N,N,N-Trimethylmethanaminium hydroxide
Other names tetramethylammonium hydroxide
Identifiers
CAS Number	75-59-2 Y 10424-66-5 (trihydrate) N 10424-65-4 (pentahydrate) Y
3D model (JSmol)	Interactive image
ChemSpider	54928 Y
ECHA InfoCard	100.000.803
PubChem CID	60966
UNII	5GKP7317Q2 Y B2HKT2LCKQ (pentahydrate) Y
CompTox Dashboard (EPA)	DTXSID3029108
InChI InChI=1S/C4H12N.H2O/c1-5(2,3)4;/h1-4H3;1H2/q+1;/p-1 Y Key: WGTYBPLFGIVFAS-UHFFFAOYSA-M Y InChI=1/C4H12N.H2O/c1-5(2,3)4;/h1-4H3;1H2/q+1;/p-1 Key: WGTYBPLFGIVFAS-REWHXWOFAQ
SMILES C[N+](C)(C)C.[OH-]
Properties
Chemical formula	C4H13NO
Molar mass	91.154 g·mol−1
Density	~ 1.015 g/cm3 (20-25% aqueous solution)
Melting point	67 °C (153 °F; 340 K) (pentahydrate)
Boiling point	decomposes
Solubility in water	high
Hazards
GHS labelling:
Pictograms	[1]
Signal word	Danger[1]
Hazard statements	H300, H311, H314[1]
Precautionary statements	P260, P264, P270, P280, P301+P310, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P322, P361, P363, P405, P501[1]
NFPA 704 (fire diamond)	3 0 0
Safety data sheet (SDS)	Sigma-Aldrich MSDS for TMAH·5H2O
Related compounds
Other anions	tetramethylammonium chloride
Other cations	tetraethylammonium hydroxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Tetramethylammonium hydroxide (TMAH or TMAOH) is a quaternary ammonium salt with molecular formula N(CH₃)₄⁺ OH⁻. It is commonly encountered in form of concentrated solutions in water or methanol. TMAH in solid state and its aqueous solutions are all colorless, but may be yellowish if impure. Although TMAH has virtually no odor when pure, samples often have a strong fishy smell due to presence of trimethylamine which is a common impurity. TMAH has several diverse industrial and research applications.