noun
definition
Any aliphatic diol.
definition
A thick, colourless liquid, C2H4(OH)2, of a sweetish taste, produced artificially from certain ethylene compounds and used as an antifreeze; ethylene glycol.
Examples of glycols in a Sentence
The tertiary glycols are known as pinacones and are formed on the reduction of ketones with sodium amalgam.
The glycols are somewhat thick liquids, of high boiling point, the pinacones only being crystalline solids; they are readily soluble in water and alcohol, but are insoluble in ether.
Two propylene glycols, C3H302, are known, viz.
Diamines.-The diamines contain two amino groups and bear the same relation to the glycols that the primary monamines bear to the primary alcohols.
In 1855, reviewing the various substances that had been obtained from glycerin, he reached the conclusion that glycerin is a body of alcoholic nature formed on the type of three molecules of water, as common alcohol is on that of one, and was thus led (1856) to the discovery of the glycols or diatomic alcohols, bodies similarly related to the double water type.
Alcohols are classified on two distinct principles, one depending upon the number of hydroxyl groups present, the other on the nature of the remaining groups attached to the carbon atom which carries the hydroxyl group. Monatomic or monohydric alcohols contain only one hydroxyl group; diatomic, two, known as glycols; triatomic, three, known as glycerols; and so on.
He observed that aldehydes and ketones may suffer reduction in neutral, alkaline, and sometimes acid solution to secondary and tertiary glycols, substances which he named pinacones; and also that certain pinacones when distilled with dilute sulphuric acid gave compounds, which he named pinacolines.
In their general behaviour towards oxidizing agents the primary glycols behave very similarly to the ordinary primary alcohols (q.v.), but the secondary and tertiary glycols break down, yielding compounds with a smaller carbon content.