A three-carbon chain of atoms.
[Greek pro, before, plus piōn, fat.]
The first chemical compound to contain this word element was propionic acid, C2H5COOH, a colourless pungent liquid organic acid produced in some forms of fermentation; its name was given it because it is the first member of the series of organic acids to form fats. From this, names have been derived for other chemical compounds containing three carbon atoms, such as the hydrocarbons propane and propylene, the pesticide propachlor, and the alcohol propanol. The adjective propyl (see -yl) refers to the radical C3H7— derived from propane, as in propyl alcohol (another name for propanol) and propylbenzene.