Metalloboranes electron counting

Mathematical cluster chemistry/Metal-metal interactions in transition metal clusters with donor ligands/Electron count versus structural arrangement in clusters based on a cubic transition metal core with bridging Main Group elements/Metalloboranes/ Clusters with interstitial atoms from the p-block How do Wade s rules handle them /Diverse naked clusters of the heavy Main Group elements Electronic regularities and analogies... 

Table I. Skeletal Electron Counting in Boranes and Metalloboranes ...

The polyhedral electron count usually correlates with the structure in the case of metalloboranes and metallocarboranes, as well as for the parent compounds. 

The metal carbonyl clusters - They have been characterized by X-ray diffraction with nuclearities up to the range 30 to 40, by the pioneering work of Chini. They are neutral or, mono-, di-, or trianionic, and these anions can be protonated to give respectively mono-, di- or trihydrides. They have been much studied by organometallic chemists who have used them as models of the Fischer-Tropsch reaction and replaced some carbonyls by unsaturated hydrocarbon ligands. Wade has compared them to metalloboranes, which allowed him to propose a new, correct electron count. Metallocarboranes, derived from the latter, were introduced by Hawthorne. 

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