H2NCO

H2NCO is a chemical shorthand that may refer to a carbamoyl-type fragment or to a transient radical species containing two hydrogens on nitrogen and a carbon–oxygen fragment. In practice, the notation most often conveys the carbamoyl unit NH2–CO, or the corresponding reactive radical form H2NCO•, rather than a discrete, isolable neutral molecule under ordinary conditions. Because H2NCO is highly reactive, it is typically discussed as an intermediate in reaction mechanisms rather than as a stable compound.

Structural considerations for H2NCO center on the connection between an amino group and a carbonyl fragment. In theoretical and kinetic studies, several electronic states and isomeric forms are examined, but no stable, well characterized neutral molecule with a definitive H2NCO structure has been isolated in standard laboratory conditions. The radical form H2NCO• is the most commonly cited reactive possibility in gas-phase chemistry, combustion, and astrochemical modeling.

Occurrences and detection are indirect. H2NCO-related intermediates are inferred from product distributions, spectroscopic signals in high-energy experiments, or computational studies that map their potential energy surfaces. In kinetic models, reactions involving H2NCO lead to products such as isocyanic acid (HNCO) or other nitrogen–carbon–oxygen species, helping to describe pathways in nitrogen-containing combustion and interstellar chemistry.

See also isocyanic acid (HNCO); the carbamoyl group; carbamoyl radical; isocyanate.