C4H4N2O2

C4H4N2O2 is the molecular formula that can correspond to several distinct chemical substances. Because the formula only specifies the counts of atoms, it does not uniquely identify a single compound; different connectivity patterns (constitutional isomers) can share this same formula.

The nominal molecular weight of C4H4N2O2 is about 112.09 g/mol. By elemental composition, it consists of roughly 42.9% carbon, 3.6% hydrogen, 25.0% nitrogen, and 28.5% oxygen. Because multiple structures fit this empirical formula, properties such as melting point, boiling point, polarity, and reactivity vary with the specific isomer.

This formula permits a variety of structural motifs, including cyclic heterocycles and open-chain arrangements that incorporate two nitrogen atoms and two oxygen atoms in different connectivities. Some isomers may feature carbonyl or imide-like functionalities, while others may be more saturated or contain different ring systems. In all cases, precise identification requires knowledge of the connectivity or additional data.

Identification and characterization typically rely on spectroscopic methods (nuclear magnetic resonance, infrared spectroscopy) and mass spectrometry, often supplemented by crystallography or computational analysis. Without a specified structure, properties and potential applications cannot be uniquely determined. The formula is most useful as a bookkeeping or comparison tool in discussions of isomerism, synthetic intermediates, or database searches.

See also: isomerism, molecular formula, heterocycles, imides, amides.