Collect. Czech. Chem. Commun. 1997, 62, 1273-1278

The Interaction of the [B10H10]2- Cage with Lewis Acids and the Formation of Decaborane Derivatives by Cage-Opening Reactions

Bernard Bonnetot, Philippe Miele, Daoud Naoufal and Henri Mongeot

Laboratoire des Multimatériaux et Interfaces UMR No. 5615, Université Claude Bernard Lyon I,43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France


The interaction of hydroborates M2[B10H10] (M = NH4, Et4N, Bu4N, etc.) or Et4N[B10H9-NH2COCH3] with Lewis acids AlX3 (X = Cl, Br, I) in the solid state is sufficiently strong to produce an increase of more than 85 cm-1 of the BH stretching vibrations. A similar interaction was not observed for the hydroborate (NH4)2[B10H9I] owing to the electronegativity of the iodine substituent which hampers the electron donor properties of the cage. Hydrolysis of (AlX3)n-[B10H10]2- adducts under mild conditions results in opening of the boron cage with the formation of halodecaboranes 6-B10H13X. It seems that this reaction proceeds only when the above adducts can form in a preliminary step. Pure hexane solutions of 6-B10H13X were easily obtained with a 45% yield for X = Cl or Br and a 30% yield when X = I.

Keywords: Decaborane; Halodecaboranes; closo-Decahydrodecaborate(2-); closo-Hydroborate anions.