propa-1,2-diene

Tricarbon (systematically named 1λ2,3λ2-propadiene and catena-tricarbon) is an inorganic compound with the chemical formula C 2(μ-C) (also written [C(μ-C)C] or C 3). It is a colourless gas that only persists in dilution or solution as an adduct. It is one of the simplest unsaturated carbenes.