Azobenzene

Part of speech: noun

Definitions

1. A type of organic compound composed of two phenyl groups connected by a nitrogen-nitrogen double bond, often used in dye and material science applications
2. An aromatic compound characterized by a linkage of two benzene rings through a diazo (-N=N-) group, frequently utilized in photochemical research
3. This molecule features a central azo group with phenyl rings on either side, playing a significant role in various chemical transformations and optical properties

Etymology: Azobenzene takes its name from two older words joined together. The first part, "azo-", comes from French "azote", the name coined in the 1780s by Lavoisier and his circle for nitrogen. The French word was built from the Greek privative prefix "a-" meaning "not" and "zōē", "life", because nitrogen does not support life, so it was seen as a gas that would extinguish a flame or kill an animal. English borrowed the element as "azote" and then used "azo-" as a combining form for compounds containing nitrogen. The second part, "benzene", traces back to "benzoe", the Latin-based name for gum benzoin, a fragrant resin from trees in Southeast Asia. Chemists who first isolated benzene in the 1820s took its name from that resin, and the Germans, who gave the word its modern shape, produced "Benzin" for the related hydrocarbon fuel, which English adopted as "benzine". Put together, "azobenzene" describes a compound in which two benzene-derived rings are linked by a nitrogen-to-nitrogen bond. Its name therefore records a compound once thought to be the "lifeless" gas and a resin that gave benzene its name.