Methylene imine is an organic compound with the chemical formula . The simplest imine, it is a stable, colorless gas that has been detected throughout the universe. Structural parameters determined by microwave spectroscopy include a C=N bond length of 1.27 ÃÂ, an NâÂÂH bond length of 1.02 àand an bond angle of 110.5ð. Because unhindered imines polymerize or oligomerize when concentrated, methylene imine has not been isolated as a liquid or bulk solid. Attempted synthesis of methylene imine from the reaction of ammonia and formaldehyde produces hexamethylenetetramine.