New synthetic routes to azacarborane clusters: nitrile insertion reactions of nido-5,6-C2B8H11- and nido-B10H13-

The nucleophilic attack of the isoelectronic nido-5,6-C2B8H11- or nido-B10H13- anions at a nitrile carbon along with nitrile hydroboration and cage insertion provides an attractive synthetic strategy for obtaining novel azacarborane clusters in good yields. Single-crystal X-ray studies of the isoelectronic clusters reveal cage frameworks containing two six-membered open faces. They may also be considered to be made up of 10-vertex arachno frameworks with exopolyhedral bridging imine substituents. An 11-vertex hypho structure is also identified.