NHCONH
NHCONH is the shorthand representation of the di-amide fragment NH-CO-NH, a ureylene or carbamoyl linkage. In structural terms, it describes a carbonyl carbon connected to two nitrogen atoms, giving the motif NC(=O)N in SMILES notation. This is the simplest example of a urea-like linkage and underpins a wide range of related compounds.
Structure and properties: The NHCONH fragment is planar due to resonance within the amide bond, giving partial
Occurrence and uses: The NHCONH linkage is central to ureas and biurets, and it forms the repeating
Reactivity and stability: As a urea-type amide, the NHCONH fragment is relatively resistant to hydrolysis under