Cyclopropene

Cyclopropene is an organic compound with the formula C3H4. It is the simplest cycloalkene. It has a triangular structure. Because the ring is highly strained, cyclopropene is both difficult to prepare and interesting to study. Like cyclopropane, the carbon ring of cyclopropene is planar. The reduced length of the double bond compared to a single bond causes the angle opposite the double bond to narrow to about 51° from the 60° angle found in cyclopropane. As with cyclopropane, the carbon–carbon bonding in the ring has increased p character: the alkene carbons use sp2.68 hybridization for the ring. [Cyclopropene. Wikipedia]