Diglyme, or bis(2-methoxyethyl) ether, is a

solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...

with a high boiling point. It is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

which is the dimethyl

ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be ...

diethylene glycol Diethylene glycol (DEG) is an organic compound with the formula (HOCH2CH2)2O. It is a colorless, practically odorless, and hygroscopic liquid with a sweetish taste. It is a four carbon dimer of ethylene glycol. It is miscible in water, alcohol, ...

. (The name ''diglyme'' is a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of wordsethylene oxide Ethylene oxide is an organic compound with the formula . It is a cyclic ether and the simplest epoxide: a three-membered ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless and flammable gas with a faintly sw ...

over an acid catalyst.

Solvent

Because of its resistance to strong bases, diglyme is favored as a solvent for reactions of alkali metal reagents even at high temperatures. Rate enhancements in reactions involving organometallic reagents, such as

Grignard reaction The Grignard reaction () is an organometallic chemical reaction in which alkyl, allyl, vinyl, or aryl-magnesium halides (Grignard reagent) is added to a carbonyl group in an aldehyde or ketone. This reaction is important for the formation of ...

s or metal hydride reductions, have been observed when using diglyme as a solvent. Diglyme is also used as a solvent in

hydroboration In organic chemistry, hydroboration refers to the addition of a hydrogen-boron bond to certain double and triple bonds involving carbon (, , , and ). This chemical reaction is useful in the organic synthesis of organic compounds. Hydroboration p ...

reactions with

diborane Diborane(6), generally known as diborane, is the chemical compound with the formula B2H6. It is a toxic, colorless, and pyrophoric gas with a repulsively sweet odor. Diborane is a key boron compound with a variety of applications. It has attracte ...

. It serves as a

chelate Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are ...

for alkali metal cations, leaving

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

s more

active Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * Active Records, a record label Ships * ''Active'' (ship), several commercial ships by that name * HMS ''Active'', the name of various ships of the British Royal ...

Safety

The European Chemicals Agency lists diglyme as a Substances of Very High Concern (SVHC) as a Reproductive Toxin. At higher temperatures and in the presence of active metals diglyme is known to decompose, which can produce large amounts of gas and heat. This decomposition led to the T2 Laboratories reactor explosion in 2007.{{Cite journal, last1=Willey, first1=Ronald J., last2=Fogler, first2=H. Scott, last3=Cutlip, first3=Michael B., date=March 2011, title=The integration of process safety into a chemical reaction engineering course: Kinetic modeling of the T2 incident, url=https://onlinelibrary.wiley.com/doi/10.1002/prs.10431, journal=Process Safety Progress, language=en, volume=30, issue=1, pages=39–44, doi=10.1002/prs.10431, hdl=2027.42/83180, s2cid=109207593, hdl-access=free

References

Glycol ethers Chelating agents