EXAFS EVIDENCE THAT THE CUCL6(4-) ION IN (3-CHLOROANILINIUM)8(CUCL6)CL4 HAS AN ELONGATED RATHER THAN COMPRESSED TETRAGONAL GEOMETRY

EXAFS measurements on (3-chloroanilinium)8(CuCl6)Cl4 in the solid state show conclusively that the-CuCl64- complex ions do not have the (unusual) tetragonally compressed geometry (a) attributed to them in an earlier X-ray crystal structure analysis. The CuCl64- ions have a normal, tetragonally elongated geometry with a significant orthorhombic component (b). Disorder of the CuCl64- ions in the crystal (b) accounts for the original crystallographic data. The, tetragonally elongated coordination geometry of the CuCl64- ions is consistent with the optical and electron paramagnetic resonance spectra of the compound.