Synthesis and crystal structure of the supramolecular solid solution [Hg6AsxSb4-x(SbBr6)Br

The solid solution [Hg6AsxSb4-x](SbBr6)Br was synthesized by the convention al ampule method. The phase extends from x = 0 to x(max) = 2.2-2.5. For the compositions with x = 0, 1.8, and 2.2, crystal structures were determined. The solid solution has a supramolecular structure based on the three-dimen sional cationic framework [Hg6As4Sb4-x](4+) andSbBr(6)(3-) and Br- anions o ccupying the larger and smaller framework cavities, respectively. Arsenic i s substituted for antimony only in the framework. The limit of substitution is most likely dictated by the decrease in the diameter of a larger cavity accommodating the octahedral SbBr63- anion.