Structural chemistry of halogenated monocarbaboranes: the extended structures of Cs[1-HCB9H4Br5], Cs[1-HCB11H5Cl6] and Cs[1-HCB11H5Br6]

Abstract

The crystal structures of the Cs⁺ salts of the halogenated monocarbaborane anions [closo-1-HCB₉H₄Br₅]⁻, [closo-1-HCB₁₁H₅Cl₆]⁻ and [closo-1-HCB₁₁H₅Br₆]⁻ have been determined. The structures show two-dimensional extended-sheet or three-dimensional lattice structures and feature unusual distorted cuboctahedral and tetrakis hexahedral coordination geometries about Cs⁺. Incidental to the structural work, new convenient preparations of the precursive non-halogenated monocarbaborane anions [closo-1-HCB₉H₉]⁻ and [closo-1-HCB₁₁H₁₁]⁻ are presented.