(Re3Br11)2− Anion in Cs2Re3Br11

Abstract

THE detailed structure of the (Re3Br11)2− anion, the formation of which was recently reported by Fergusson and Robinson1, has been determined by means of X-ray crystal structure analysis of its caesium salt. It shows the same general configuration as the (Re3Cl11)2− ion (ref. 2) Detailed analysis of bond lengths and angles reveals some interesting differences between the (Re3Cl12)3− ion (refs. 3 and 4) and the two (Re3X11)2− ions, which raise questions as to the nature of the chemical bonds involved. Further, there is an important difference between (Re3Cl11)2− and (Re3Br11)2−.