Tetrabutylammonium hydroxide is the chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

 with the formula (C₄H₉)₄NOH, abbreviated Bu₄NOH with the acronym TBAOH or TBAH. This species is not readily obtainable as a pure compound, but it employed as a solution in water or alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

s. It is commonly used as a base in organic chemistry

Organic chemistry

Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...

. Relative to more conventional inorganic bases, such as KOH

Potassium hydroxide

Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...

 and NaOH, Bu₄NOH is more soluble in organic solvents. Attempted isolation of pure Bu₄NOH induces Hofmann elimination

Hofmann elimination

Hofmann elimination is a process where an amine is reacted to create a tertiary amine and an alkene by treatment with excess methyl iodide followed by treatment with silver oxide, water, and heat.After the first step, a quaternary ammonium iodide salt is created...

, leading to Bu₃N and 1-butene

1-Butene

1-Butene is an organic chemical compound, linear alpha-olefin , and one of the isomers of butene. The formula is .-Stability:1-Butene is stable in itself but polymerizes exothermically. It is highly flammable and readily forms explosive mixtures with air...

. Solutions of Bu₄NOH are typically contaminated with Bu₃N for this reason.

Applications

Bu₄NOH is a strong base that is used often under phase-transfer

Phase transfer catalyst

In chemistry, a phase transfer catalyst or PTC is a catalyst that facilitates the migration of a reactant from one phase into another phase where reaction occurs. Phase transfer catalysis is a special form of heterogeneous catalysis. Ionic reactants are often soluble in an aqueous phase but...

 conditions to effect alkylation

Alkylation

Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion or a carbene . Alkylating agents are widely used in chemistry because the alkyl group is probably the most common group encountered in...

s and deprotonation

Deprotonation

Deprotonation is the removal of a proton from a molecule, forming the conjugate base.The relative ability of a molecule to give up a proton is measured by its pKa value. A low pKa value indicates that the compound is acidic and will easily give up its proton to a base...

s. Typical reactions include benzyl

Benzyl

In organic chemistry, benzyl is the term used to describe the substituent or molecular fragment possessing the structure C6H5CH2-. Benzyl features a benzene ring attached to a CH2 group.-Nomenclature:...

ation of amines and generation of dichlorocarbene

Dichlorocarbene

Dichlorocarbene is a carbene commonly encountered in organic chemistry. This reactive intermediate with chemical formula CCl2 is easily available by reaction of chloroform and a base such as potassium t-butoxide or sodium hydroxide dissolved in water...

 from chloroform

Chloroform

Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...

.

Bu₄NOH can be neutralize

Neutralization

In chemistry, neutralization, or neutralisation is a chemical reaction in which an acid and a base react to form a salt. Water is frequently, but not necessarily, produced as well. Neutralizations with Arrhenius acids and bases always produce water:Y and X represent a monovalent cation and anion...

d with a variety of mineral acid

Mineral acid

A mineral acid is an acid derived from one or more inorganic compounds. A mineral acid is not organic and all mineral acids release hydrogen ions when dissolved in water.-Characteristics:...

s to give lipophilic salts of the conjugate base. For example, treatment of Bu₄NOH with disodium pyrophosphate

Disodium pyrophosphate

Disodium pyrophosphate or sodium acid pyrophosphate is a buffering and chelating agent, with many food and industrial uses. It is polyvalent, and acts as a Lewis base, so is effective at binding polyvalent cations.-Food uses:...

, Na₂H₂P₂O₇, gives (Bu₄N)₃[HP₂O₇], which is soluble in organic solvents. Similarly, neutralization of Bu₄NOH with hydrofluoric acid

Hydrofluoric acid

Hydrofluoric acid is a solution of hydrogen fluoride in water. It is a valued source of fluorine and is the precursor to numerous pharmaceuticals such as fluoxetine and diverse materials such as PTFE ....

 affords Bu₄NF

Tetra-n-butylammonium fluoride

Tetra-n-butylammonium fluoride or TBAF is a quaternary ammonium salt with the chemical formula 4N+F-. It is commercially available as the trihydrate and as a solution in tetrahydrofuran....

. This salt dissolves in organic solvents and is useful to desilylation.