Diol

Diols are organic compounds containing two alcoholic hydroxyl groups (-OH) included, so divalent alcohols ( " dialcohols ").

An example of a simple, stable diol is ethylene glycol ( 1,2-ethanediol ).

Classification

Depending on the relative position of the two alcoholic hydroxyl groups in the molecule, a distinction between

With 1,2- diols, which are derived for example from a cycloalkane, a distinction is made between the cis -1 ,2- diol and trans-1 ,2- diols.

Polyethylene glycols

α, ω - diols resulting from the condensation of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol.

Enediols

Enediols (or reductones ) are a sub- group of the diols.

Aldehyde hydrates

The formally simplest - stable only in aqueous solution - diol is the aldehyde hydrate of formaldehyde, the Methandiol. Many textbooks, however, are not to aldehyde hydrates the diols.

Dihydroxybenzenes

Dihydroxybenzenes not among the diols, as well as phenol is not taken into alcohols.

Use

1,2- ethanediol is used as antifreeze in water-cooled internal combustion engines. Diols is needed (when the polyurethane ) in the chemical industry in the manufacture of polyesters, polycarbonates and polyurethanes by means of polycondensation and polyaddition. Plastic fibers of polyesters find in the textile industry under the trade name diols using.

Higher homologs

Polyols - to which the carbohydrates are - containing more than two hydroxyl groups. Examples of triols having three hydroxyl groups are glycerol ( " Propanetriol " ) and calcitriol.