Pyrrole

Part of speech: noun

Pronunciation: /ˈpɪɹəʊl/

Definitions

1. A cyclic compound characterized by a five-membered ring that includes one nitrogen atom, often found in various biological contexts and synthetic materials
2. A nitrogen-containing organic structure composed of five atoms in a ring format, significant in the study of biological pigments and synthetic chemistry
3. A five-membered aromatic ring structure containing one nitrogen atom, prevalent in natural pigments and pharmaceutical applications

Etymology: Pyrrole's name comes from a colour. In ancient Greek, "purrhos" meant "reddish" or "fiery," and it was built on "pur," the word for fire. Chemists gave the name to this compound in German as "Pyrrol," and English adopted it from there. The suffix "-ole" was added in the same tradition that produced names for related ring compounds. The reason for the colour link is a chemical reaction. Pyrrole turns red when it is treated with a pine splinter soaked in hydrochloric acid, a test chemists used to identify it. The name thus records a laboratory reaction rather than the compound's appearance, which is a colourless liquid.