C3H3NO

C3H3NO is the molecular formula that denotes several constitutional isomers containing three carbon atoms, one nitrogen atom, one oxygen atom, and three hydrogens. The best-known representatives are the heterocyclic rings oxazole and isoxazole, which share the same empirical formula but differ in the positions of the heteroatoms.

Oxazole refers to a five-membered aromatic ring with one oxygen and one nitrogen atom separated by one carbon atom (the 1,3-oxazole arrangement). Isoxazole is an isomer in which the nitrogen and oxygen atoms are adjacent (the 1,2-oxazole arrangement). Both rings are common scaffolds in organic chemistry and appear in a variety of substituted derivatives used in research and drug design. Substituted oxazoles and isoxazoles can be prepared with diverse groups at different ring positions, leading to a wide range of physical and chemical properties.

Because several distinct structures share the same formula, C3H3NO is not sufficient to identify a specific compound without additional structural information such as a name, SMILES string, or spectral data. The molecular weight of compounds with this formula is approximately 69.06 g/mol. In practice, these rings are valued for their aromatic stability, planarity, and ability to participate in hydrogen bonding and coordination chemistry, making them useful in medicinal chemistry, agrochemicals, and materials science.

In summary, C3H3NO most prominently represents oxazole and isoxazole families, but the exact structure must be specified to determine a particular compound.