CHEMICAL APPLICATIONS OF TOPOLOGY AND GROUP THEORY .2. METAL COMPLEXES OF PLANAR UNSATURATED CARBON SYSTEMS

The geometries of minimum diameter planar networks of linked sp2 carbon atoms are considered. Empirical data suggest that those with diameters less than about 2.1 carbon-carbon bond lengths can entirely bond to a single metal atom whereas those with larger diameters bond either partially to a single metal atom or entirely to two metal atoms. The π-electronic structures of such planar networks of linked sp2 carbon atoms all have a lowest lying σ-bonding molecular orbital followed by one or, more commonly, two orthogonal, higher lying but generally bonding or nonbonding π molecular orbitals. The possible coordination polyhedra for metal complexes with one or two such orthogonally double π-donor ligands or with one single π-donor ligand are considered using the techniques developed in the first paper of this series1 and compared with the geometries found in some known complexes. © 1969, American Chemical Society. All rights reserved.