Planar tetracoordinate carbons in cyclic semisaturated hydrocarbons

(Figure Presented) A series of planar tetracoordinate carbon molecules in cyclic semisaturated hydrocarbons resulting from the combination of the C ₅ ^2- skeleton with saturated hydrocarbon fragments is reported. The electronic stabilization and the bonding situation are studied through the analyses of molecular orbitals and the electron localization function. The magnetic properties are also revised, giving particular attention to the induced magnetic field. These systems are the first semisaturated cycles containing a planar tetracoordinate carbon stabilized only by electronic factors.