Dicarbon monoxide (C2O) is a molecule that contains two carbonatoms and one oxygen atom. It is a linear molecule that, because of its simplicity, is of interest in a variety of areas. It is, however, so extremely reactive that it is not encountered in everyday life. It is classified as a carbene, cumulene and an oxocarbon.[1]
The organophosphorus compound (C6H5)3PCCO (CAS# 15596-07-3) contains the C2O functionality. Sometimes called Bestmann's Ylide, it is a yellow solid.[6]
^Jensen, Michael P.; Shriver, Duward F. "Carbon-carbon and carbonyl transformations in ketenylidene cluster compounds" Journal of Molecular Catalysis 1992, vol. 74, pp. 73-84. doi:10.1016/0304-5102(92)80225-6
^H. J. Bestmann, R. Zimmermann, M. Riou "Ketenylidenetriphenylphosphorane" e-EROS Encyclopedia of Reagents for Organic Synthesis 2001. doi:10.1002/047084289X.rk005.pub2