C2H4NO2

C2H4NO2 is the molecular formula representing a chemical composition that includes two carbon atoms, four hydrogen atoms, one nitrogen atom, and two oxygen atoms. As a formula, it does not specify a unique compound because multiple structural isomers and charged species can share the same elemental composition. In chemical databases, C2H4NO2 is typically listed as a formula entry rather than a single defined molecule.

For a neutral, closed-shell molecule with this formula, the degree of unsaturation calculation yields a non-integer value (1.5). Since the degree of unsaturation is expected to be an integer for neutral molecules, this implies that any strictly neutral, non-radical species with this exact composition cannot exist in standard valence terms. Consequently, observed forms of C2H4NO2 in practice are usually ions (cations or anions) or radical species, or fragments within larger salts or coordination compounds.

In practice, C2H4NO2 may appear in mass spectrometric data as a fragment or adduct, or be considered in theoretical studies of possible ionic species and reaction intermediates. The formula can correspond to different structural motifs depending on how the atoms are connected, such as various carbonyl, amine, or other oxygen- and nitrogen-containing functionalities on a two-carbon backbone. However, identifying the exact properties of any given instance requires knowledge of the specific connectivity and charge state.

See also: chemical formula, isomer, mass spectrometry, glycine (C2H5NO2) for comparison.