Edge-localized bonding

Consideration of the properties of vertex groups leads to the following very simple rule to determine whether polygonal or polyhedral molecules exhibit delocalized bonding or edge-localized bonding ... 

The matching rule cited above implies that fully edge-localized bonding occurs in a polyhedral molecule in which all vertices have degree 3. Such is the case for the... 

Degree 3 vertices Only three two-center B-B bonds along the polyhedral edges corresponding to edge-localized bonding or three three-center B-B-B bonds in the polyhedral faces are possible. 

Z = 0 for all polyhedra in which all vertices have degree 3 such as the tetrahedron, cube, and dodecahedron. These are the polyhedra exhibiting edge-localized bonding. 

Fig. 11 The edge-localized bonding model for Os3(CO)i2 showing the three 2c-2e bonds along with the a-aromatic model showing the 3c-2e core bond with Hiickel topology and the 3c-4e perimeter bond with MSbius topology. Reprinted with permission from [123], Copyright-. Elsevier...

Figure 15 Examples of polyhedra with all vertices of degree three found in the polyhedranes C H (n = 4, 8, 20), which exhibit edge-localized bonding...

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