THE X-RAY CRYSTAL-STRUCTURES OF DOUBLE SALTS OF HEXAHALORHODATE(III) AND HALIDE WITH THE ETHANE-1,2-DIAMMONIUM CATION

The compounds precipitated on adding 1,2-diaminoethane (en) to hexachl ororhodate(III) and hexabromorhodate(III) solutions in hydrochloric an d hydrobromic acids, although classically described as anhydrous, are actually the hydrated [enH(2)](2)[RhCl6][Cl] . H2O and [enH(2)](2)[RhB r6][Br] . H2O. The X-ray crystal structures of both compounds are repo rted. In each case,the cations adopt a trans conformation and the comp lex anion closely approximates to O-h symmetry. However, the crystals are not isostructural, but closely related. The c axis of the chloride is approximately double that of the bromide. Some spectroscopic and c hemical properties of the double salts are given.