Condensed polyhedral clusters

In a condensed polyhedral cluster, two or more polyhedral cages are fused together through atom, edge or face sharing. 

Examples of these families of condensed polyhedral clusters are Os5(CO)j9 (atom-sharing, 23.30), H20s5(C0)ig (edgesharing, 23.31) and H20sg(C0)ig (face-sharing, 23.32). 

Factors Affecting the Stability of Condensed Polyhedral Clusters... 

In high-nuclearity clusters containing deltahedral or condensed polyhedral skeletons, the CVE count predicted by SEPT is often observed. Some unusual core geometries may be found, e.g., in Os6Pt2(/i-H)2(/i-CsH10)(CO)16(COD) (85), which are less straightforward to rationalize. 

Exo-polyhedral interactions (Figure 5.19) do not affect the skeletal bonding in individual monomeric units and hence Wade s rales can stiU be applied. These macro-polyhedral boranes where Wade s rule is apphcable can be called connected polyhedral boranes, in contrast to condensed polyhedral boranes in which the monomeric units share one or more boron vertices and do not obey Wade s rale. In order to be applicable to condensed polyhedral boranes as well, Wade s rule can be extended by incorporating a new variable, m, corresponding to the number of polyhedra. In Wade s n-i-l-i-p rale, 1 is added to include the core BMO. If m closo clusters condense to form a condensed polyhedral borane, there will be m core BMOs. Thus, the n-El-Ep rale can be modified to where m is the... 

Jemmis, E.D. and Pancharatna, P.D. (2003) Condensed polyhedral boranes and analogous organometallic clusters a molecular orbital and density functional theory study on the cap-cap interactions. Appl. Organomet. Chem., 17 (6-7), 480 492. 

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