Base degradation of ortho carborane gives the anionic 11-vertex derivative, precursor to dicarbollide complexes:
:CBH  +  NaOEt  +  2 EtOH  →  NaCBH  +  H  +  B(OEt)
:NaCBH  +  NaH  →  NaCBH  +  H
Dicarbollides (CBH) function as ligands for transition metals and f-elements. The dianion forms sandwich compounds, bis(dicarbollides). Dicarbollides, being strong electron donors, stabilize higher oxidation states, e.g. Ni(IV).