[1] This highly strained and reactive molecule was synthesized and characterized for the first time in 1984, and has been the subject of considerable experimental and theoretical interest.

Methylenecyclopropene is the smallest of the fulvenes (a family of unstable, cyclic molecules, conjugated transversally with an odd number of carbon atoms in the ring).

The structure of methylenecyclopropene has two interacting double bonds, which represents the simplest transversally conjugated π-bonding system.

Most fulvenes are typically non-aromatic in nature (based on spectroscopic data), having properties closer to alkenes.

Similarly to heptafulvene (fulvene containing a 7-atom cyclic ring), triafulvene polymerizes easily at −20 °C and is stabilized by electron-accepting groups bonded to the methylidene carbon atom.