1.Previous
3.Next

carbon suboxide (O?C -> C⁰ <- C?O), tetraaminoallenes (described using dative bond language as "carbodicarbenes"; (R₂N)₂C -> C⁰ <- C(NR_{2)2), the Ramirez} carbodiphosphorane (Ph₃P -> C⁰ <- PPh_{3), and bis(triphenylphosphine)iminium cation (Ph3P -> N⁺ <- PPh3), all of which exhibit considerably bent equilibrium geometries, though with a shallow barrier to bending. Simple application of the normal rules for drawing Lewis structures by maximizing bonding (using electron-sharing bonds) and minimizing formal charges would predict heterocumulene structures, and therefore linear geometries, for each of these compounds. Thus, these molecules are claimed to be better modeled as coordination complexes of :C: (carbon(0) or carbone) or :N:⁺ (mononitrogen cation) with CO, PPh3, or N-heterocycliccarbenes as ligands, the lone-pairs on the central atom accounting for the bent geometry. However, the usefulness of this view is disputed.}

1.Previous
3.Next