cyclopropadiene
Cyclopropadiene is a highly strained organic compound with the chemical formula C3H2. It consists of a three-membered ring of carbon atoms, with two double bonds. This arrangement makes cyclopropadiene a very unstable and reactive molecule. It is the smallest possible annulene, a class of cyclic hydrocarbons with alternating single and double bonds. The presence of the two double bonds within such a small ring leads to significant ring strain and deviation from planarity, although it can be considered a theoretical aromatic system.
Cyclopropadiene itself is difficult to isolate and study due to its extreme reactivity. It readily undergoes