Trimethyloxosulfonium Salts. IX. Study of some Mixed Compounds, (CH₃)₃SOCdCl_3-xBr_x

Crystal structures of six (CH₃)₃SOCdCl_3 - xBr_x mixed compounds [(1) x = 2.116, (2) x = 1.787, (3) x = 1.183, (4) x = 0.962, (5) x = 0.607, (6) x = 0.286] have been determined. Each has space group Pnma and is a structural analogue of (CH₃)₃SOCdCl₃ and (CH₃)₃SOCdBr₃, reported previously. The distribution of Br and Cl atoms among the two anionic sites was especially studied. We have shown that the occupation probabilities are related to the x value but do not vary with it linearly: the Cl atoms marked a preference for the most symmetric site (m symmetry) while the Br atoms were better located on a general position more distant from the Cd ion. It is therefore not possible to describe these mixed compounds in terms of continuous solid solutions series.

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