Closo-halogenohydrohexaborate. Pt. 2

The point symmetries of the halogenohydrohexaborates within the nearly complete series XnB6H6-n2-, X = Cl, Br, I; n = 1-5, are determined from the 11B and 11B{1H} NMR spectra, which show characteristic features for homologous isostructural compounds related to the electronegativity of the substituents. The chemical shifts are mainly influenced by -I, +M, and in the case of X = I by the heavy atom effect. Along with a strong antipodal effect a slight vicinal influence between neighbours in the B6 cage is observed, increasing with the number of substituted atoms. (orig.)