Chem. Short combining form of AZOTE, nitrogen. Used to form the names of:
1. gen. Compounds containing nitrogen, as Azohumic, nitrogenized humic (acid); Azolitmin, the principal coloring matter of litmus; Azoleic, an acid formed by treating oleic with nitric acid.
2. spec. Substitution compounds in which nitrogen takes the place of another element, as in the Azoparaffins, formed from the paraffins by substitution of 1 atom of nitrogen for 3 of hydrogen; e.g., azo-methane = hydrogen cyanide, azo-ethane = methyl cyanide, azo-propane = ethyl cyanide, etc.
3. more particularly. Compounds derived from the aromatic hydrocarbons, which contain nitrogen combined in a peculiar way, constituting the azo- and diazo- compounds, or azo- derivatives, e.g., azobenzene, azotoluene; diazo-amidobenzene, diazobromide; whence adjectives as azobenzo·ic, etc.
1881. Darwin, Veg. Mould, v. 242. Some of the acids, which were called long ago azohumic, are enabled to dissolve colloid silica in proportion to the nitrogen which they contain.
1863. Watts, Dict. Chem., III. 731. Azolitmin is a red-brown amorphous powder.
1880. Cleminshaw, trans. Wurtz’ Atom. The., 219. Those very remarkable organic combinations known as azo- and diazo-compounds.
1880. Friswell, in Soc. Arts Jrnl., 445. Known as the azo-yellows, oranges, and scarlets.
