Methoxide
Encyclopedia
Methoxides are organic salts and the simplest alkoxides
. Sodium methoxide
and potassium hydroxide have widespread use, though other variants such as lithium hydroxide, rubidium methoxide, caesium methoxide, and francium methoxide exist as well.
, the methoxide ion has a formula of CH3O- and is the conjugate base of methanol
. It is an extremely strong base
, even stronger than the hydroxide
ion. As such, methoxide solutions must be kept free of water; otherwise, the methoxide will remove a proton from a water molecule, yielding methanol and hydroxide.
methylate and sodium methanolate, is a white powder when pure. It is used as an initiator
of an anionic addition polymerization
with ethylene oxide
, forming a polyether with high molecular weight. Both sodium methoxide and its counterpart prepared with potassium
are frequently used as catalysts for commercial-scale production of biodiesel
. In this process, vegetable oils or animal fats, which chemically are fatty acid triglycerides, are transesterified
with methanol to give fatty acid methyl ester
s (FAMEs).
Sodium methoxide is produced on an industrial scale and available from a number of chemical companies.
Sodium methoxide in methanol is a liquid that kills human nerve
cells before any pain can be felt. In the event of contact with methoxide, rinse the contacted area with water, seek medical attention immediately.
in the production of biodiesel
.
Alkoxide
An alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They can be written as RO−, where R is the organic substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands...
. Sodium methoxide
Sodium methoxide
Sodium methoxide is a chemical compound, with formula CH3ONa. This colourless solid, which is formed by the deprotonation of methanol, is a widely used reagent in industry and the laboratory...
and potassium hydroxide have widespread use, though other variants such as lithium hydroxide, rubidium methoxide, caesium methoxide, and francium methoxide exist as well.
Methoxide ion
In organic chemistryOrganic 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...
, the methoxide ion has a formula of CH3O- and is the conjugate base of methanol
Methanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...
. It is an extremely strong base
Base (chemistry)
For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...
, even stronger than the hydroxide
Hydroxide
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and a hydrogen atom held together by a covalent bond, and carrying a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, as a ligand, a nucleophile, and a...
ion. As such, methoxide solutions must be kept free of water; otherwise, the methoxide will remove a proton from a water molecule, yielding methanol and hydroxide.
Sodium methoxide
Sodium methoxide, also called sodiumSodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
methylate and sodium methanolate, is a white powder when pure. It is used as an initiator
Initiator
An initiator can refer to:* A person that takes an initiative in making something happen.* Modulated neutron initiator, a neutron source used in some nuclear weapons...
of an anionic addition polymerization
Anionic addition polymerization
Anionic addition polymerization is a form of chain-growth polymerization or addition polymerization that involves the polymerization of vinyl monomers with strong electronegative groups. This polymerization is carried out through a carbanion active species. Like all addition polymerizations, it...
with ethylene oxide
Ethylene oxide
Ethylene oxide, also called oxirane, is the organic compound with the formula . It is a cyclic ether. This means that it is composed of two alkyl groups attached to an oxygen atom in a cyclic shape . This colorless flammable gas with a faintly sweet odor is the simplest epoxide, a three-membered...
, forming a polyether with high molecular weight. Both sodium methoxide and its counterpart prepared with potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
are frequently used as catalysts for commercial-scale production of biodiesel
Biodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....
. In this process, vegetable oils or animal fats, which chemically are fatty acid triglycerides, are transesterified
Transesterification
In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R′ of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst...
with methanol to give fatty acid methyl ester
Fatty acid methyl ester
A fatty acid methyl ester can be created by an alkali catalyzed reaction between fats or fatty acids and methanol. The molecules in biodiesel are primarily FAMEs, usually obtained from vegetable oils by transesterification....
s (FAMEs).
Sodium methoxide is produced on an industrial scale and available from a number of chemical companies.
Sodium methoxide in methanol is a liquid that kills human nerve
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
cells before any pain can be felt. In the event of contact with methoxide, rinse the contacted area with water, seek medical attention immediately.
Potassium methoxide
Potassium methoxide is commonly used as a catalyst for transesterificationTransesterification
In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R′ of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst...
in the production of biodiesel
Biodiesel production
Biodiesel production is the process of producing the biofuel, biodiesel, through either transesterification or alcoholysis. It involves reacting vegetable oils or animal fats catalytically with a short-chain aliphatic alcohols ....
.