Geometry of the (B8C2H10·C5H5N2–) anion from an X-ray structural analysis of [Et4N+][(B9C2H11) Co(B8C2H10·C5H5N)–]

Abstract

The crystal structure of [Et₄N⁺][(B₉C₂H₁₁)Co(B₈CH₁₀·C₅H₅N)^–] has been elucidated; the d⁶ cobalt(III) ion is “sandwiched” between mutually-staggered (B₉C₂H₁₁^2–) and (B₈C₂H₁₀·C₅H₅N^2–) ions, the latter of these having a unique B₈C₂ skeleton which defines an icosahedron from which two adjacent apices have been removed; it is linked to cobalt via an open 4-atom (C–B–B–B) bonding face.