C5H5NS

C5H5NS is the molecular formula for several chemical compounds, most notably pyridine and its isomers. Pyridine itself is a basic heterocyclic organic compound with the chemical formula C5H5N. It is a six-membered ring with one nitrogen atom and five carbon atoms. Pyridine is a colorless liquid with a distinct, unpleasant odor. It is miscible with water and most organic solvents. Pyridine is used as a solvent and as a precursor to many other chemicals, including pharmaceuticals and agrochemicals.

The isomers of C5H5NS, where the sulfur atom replaces a carbon atom in the pyridine ring, are less common. One example is thiophene, which has the molecular formula C4H4S. Thiophene is a five-membered aromatic ring containing one sulfur atom. It is a colorless liquid with a benzene-like odor. Thiophene is also used as a solvent and as a building block for various organic synthesis. Other isomers with the formula C5H5NS are theoretically possible but are not as widely encountered or studied as pyridine or thiophene. The specific arrangement of atoms within the C5H5NS formula dictates the compound's properties and reactivity.