Carbo-[3]oxocarbon and its isomers: evaluation of the stability and of the electron delocalization.
Various isomers of carbo-[3]oxocarbon C9O3 have been characterized on the singlet and triplet spin state potential energy surfaces. Despite its localized structure, the ring carbo-mer of [3]oxocarbon is thermodynamically protected from subsequent isomerization and stable versus dissociation into C3O. It therefore appears as a reasonable synthetic target. In contrast, the less stable tetracyclic isomer exhibits electron delocalization both in the central six-membered ring and in the external three-membered rings, as evidenced from structural, magnetic and electron localization function (ELF) analysis. Another monocyclic isomer may be considered as a planar C6(CO)3 "carbon-complex", a carbon version of the related iron carbonyl complex Fe(PH3)2(CO)3. C6 and Fe(PH3)2 are indeed isolobal on the basis of frontier orbital analysis.
Laboratoire de Chimie de Coordination, UPR 8241 CNRS, 205 Route de Narbonne, 31077, Toulouse cedex 4, France.
Mickaël
M
Gicquel
Jean-Louis
JL
Heully
Christine
C
Lepetit
Remi
R
Chauvin