Toluyl

Part of speech: noun

Definitions

1. The chemical group CH3C6H4 derived from toluene by removing one hydrogen atom from its aromatic ring or methyl side chain
2. A univalent organic radical formed from toluene, used as a building block in the synthesis of many aromatic compounds
3. A substituent group related to toluene that carries a benzene ring with a methyl group, found in various dyes and chemicals

Etymology: Toluyl is a chemical radical, the name given to the group of atoms left behind when a toluic acid loses its hydroxyl part. The word is built in the plain way chemists named such groups: "toluic" from toluene, the hydrocarbon whose name comes from balsam of Tolu, and the suffix "-yl", which marks a radical. So the name carries a trace of a South American tree, since toluene takes its name from Tolu, a town in Colombia whose balsam was once prized. The "-yl" ending has its own history. It was coined in the early nineteenth century from the Greek "hylē", meaning wood or matter, when chemists were trying to name the stable groups that passed unchanged from one compound to another. Chemists treated these groups as the building blocks of organic molecules, and the suffix became a standard way to label them. Toluyl itself is used mainly in the names of compounds, where it marks a part of a molecule that comes from toluic acid.