Main Page | See live article | Alphabetical index Pyridine is one of the most simple heteroaromatic molecules, with the Hill system formula C5H5N. Pyridine is structurally similar to benzene, with a single nitrogen atom substituting in the six-member aromatic ring for one of the carbon and one of the hydrogen atoms. Pyridine is a base. Its conjugate acid is a unipositive polyatomic ion called pyridinium, C5H5NH+. Under conditions of standard temperature and pressure, pyridine is a liquid with a strong odor. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.