What is "tricarbon"

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

It is a small carbon cluster first spectroscopically observed in the beginning 20th century in the tail of a comet by William Huggins and subsequently identified in stellar atmospheres. Tricarbon can be found in interstellar space and can be produced in the laboratory by a process called laser ablation. Small carbon clusters like tricarbon and dicarbon are regarded as soot precursors and are implicated in the formation of certain industrial diamonds and in the formation of fullerenes. The ground state molecular geometry of tricarbon has been identified as linear via its characteristic symmetric and antisymmetric stretching and bending vibrational modes and bears bond lengths of 129 to 130 picometer corresponding to those of alkenes. The ionization potential is determined experimentally at 11 to 13.5 electron-volts. In contrast to the linear tricarbon molecule the C cation is bent.

C has also been identified as a transient species in various combustion reactions.

The generation of C was investigated by Professor Emeritus Philip S. Skell of Pennsylvania State University in the 1960s.