Dimethylpyridines

Part of speech: noun

Definitions

1. Organic chemical compounds made from a pyridine ring carrying two methyl groups attached to its carbon atoms
2. Heterocyclic bases in which two hydrogen atoms of pyridine have been replaced by methyl groups, forming a family of isomers
3. Nitrogen-containing aromatic compounds, each a pyridine molecule bearing a pair of methyl substituents, used in chemical synthesis

Etymology: "Dimethylpyridines" is the plural of "dimethylpyridine", a chemical name built mechanically from two parts. Pyridine is a six-membered ring containing one nitrogen atom, a compound with a sharp, unpleasant smell that chemists have long known. The prefix "dimethyl" signals that two methyl groups, each a single carbon atom bonded to three hydrogens, have been attached to that ring in place of hydrogen atoms. The plural form reflects the fact that there is more than one way to arrange those two methyl groups around the ring. Each arrangement produces a distinct isomer, a compound with the same formula but a different structure and different properties. So the plural names the whole family of these isomers rather than a single substance.