Guanidyl
Guanidyl is a functional group in organic chemistry with the chemical formula (NH2)2C=NH. It is characterized by a central carbon atom double-bonded to one nitrogen atom and single-bonded to two other nitrogen atoms. These nitrogen atoms are typically part of amino groups, making guanidyl a derivative of guanidine. The guanidyl group is a basic moiety due to the delocalization of positive charge within the C-N system, which stabilizes the protonated form. This basicity is a key feature of many compounds containing the guanidyl group.
The guanidyl group is found in several biologically important molecules. Perhaps the most well-known example is