Thereby, the resulting silver tetrahedron and the sulfur octahedron have a common centroid. Although the anion 9 is chiral because the six sulfur atoms are functional groups of bidentate ligands, both enantiomers occur with equal abundance in the centrosymmetric crystals of 10 (cf. Ref. [lo]). In Figure 2 the sulfur atoms which belong to the same ligands are connected by filled edges of the octahedron.
In its idealized form 9 has C3 symmetry, whereby the threefold axis passes through Ag(l) and the center of the Ag(2)-Ag(3)-Ag(4) triangle. The mean S-Ag-S valence angle is 119.84" and thus indicates that the AgS,-coordination centers are not completely planar. The S-Ag-S chelate angles, with an average value of 112.62", are very small. Compared to the corresponding copper compound,"' the larger metal-sulfur bond lengths lead to a diminution of the angle in the chelate ring of about 5". In addition to the small angle in the chelate ring, the atoms Ag(2), Ag(3), and Ag(4) are each characterized by a somewhat larger (example: S(l)-Ag(2)-S(3); mean value 115.20') and a very much wider valence angle (example: S(2)-Ag(2)-S(3); mean value 131.58"). Moreover, there are two shorter (mean value 2.468 A) and one somewhat longer Ag-S bond (mean value 2.572A) around each of the atoms Ag(2), Ag(3), and Ag(4). Interestingly, there are differences in the bond lengths within the S-Ag-S chelate fragments, the longer bonds being formed to the sulfur atoms that are also bound to Ag( 1) (example: Ag(2)-S( 1)). Compared to this, valence angles of 113.30(4), 122.77(4), and 123.78(4)" and Ag_S bond lengths of 2.475(1), 2.521(1), and 2.532( 1) A are observed at Ag(1). Thus, the distortion of the real molecule is clearly documented, since C3 symmetry requires equal valence angles and equal bond Iengths.