Sulphonic

Part of speech: adjective

Definitions

1. Relating to or containing the sulphonic group, a chemical grouping of sulphur bonded to oxygen atoms that is found in certain acids
2. Describing a compound that includes the sulphonic group, which consists of a sulphur atom linked to three oxygen atoms within a molecule
3. Characterizing chemical substances that carry the sulphonic group, a functional unit used in many dyes, detergents and organic acids

Etymology: "Sulphonic" is the British spelling variant of "sulfonic," and the two spellings share one history. The term belongs to chemistry, where it describes compounds containing the group of atoms known as the sulfonyl group, which pairs a sulfur atom with two oxygen atoms. Its root is "sulfur," the element, and the "-onic" ending is the same one found in other chemical adjectives, such as "sulfuric" acid, which the source directs readers to as the parent form. The element's name traces back much further than the chemistry. "Sulfur" entered English from Old French, and before that from Latin "sulphur," a word whose ultimate origins are obscure. Chemists in the 19th century, when systematic naming of compounds took shape, built a family of terms from that root, so "sulfonic" is a technical coinage from classical materials rather than an ancient word. Its exact date of entry into English is not recorded in the source, so it is best understood as a product of modern chemical nomenclature.