H2CNH

H2CNH is the chemical formula for methylenimine, CH2NH, a simple imine that features a carbon–nitrogen double bond with a methylene substituent. It is often represented as H2C=NH. The molecule is small and highly reactive, typically described as a reactive intermediate and a versatile building block in organic synthesis.

In terms of structure, methylenimine is generally considered planar around the C=N bond, with the methylene (CH2) group attached to carbon and the nitrogen bearing a lone pair. The molecule is volatile and unstable under many conditions, especially in the presence of water or oxygen, where it readily undergoes hydrolysis or oxidation. It can also polymerize or participate in rapid addition reactions, which limits its stability outside specialized environments.

Production and applications: methylenimine can be generated in situ in the laboratory by dehydrogenation of methylamines or by dehydration of formaldehyde with ammonia under appropriate conditions. It serves as a reactive precursor for introducing the CH2NH moiety into larger molecules and is used in the synthesis of azomethine derivatives and various heterocycles. Due to its reactivity, it is typically handled under controlled, low-temperature or inert conditions.

Safety and detection: methylenimine is toxic and flammable, requiring appropriate safety precautions and containment. It has been the subject of spectroscopic and theoretical studies, including measurements of its rotational spectrum, which support quantum-chemical modeling and help validate computational methods for small imines.

Overall, H2CNH is a prototypical reactive imine with limited stability outside controlled settings but serves as a valuable intermediate in organic synthesis and chemical research.