Structural features of Ag[AuF4] and Ag[AuF6] and the stuctural relationship of Ag[AgF4]2 and Au[AuF4]2 to Ag[AuF4]2

Synchrotron radiation X-ray powder diffraction data (SPDD) have been obtained for Ag[AgF4](2), Au[AuF4](2), Ag[AuF4], and Ag[AuF4](2). Ag[AgF4](2) and Au[AuF4](2) are isostructural with Ag[AuF4](2), space group (SG) P2(l)/n, Z = 2, with the following: for Ag[AgF4](2) a = 5.04664(8), b = 11.0542(2), c = 5.44914(9) Angstrom, beta 97.170(2)degrees; for Au[AuF4](2) a = 5.203(2), b = 11.186(3), c = 5.531(2) Angstrom, beta 90.55(2)degrees. The structure of Ag[AgF4](2) was refined successfully (SPDD) applying the Rietveld method, yielding the following interatomic distances (Angstrom): Ag-II-F = 2.056(12), 2.200(13), 2.558(13); Ag-III-F = two at 1.846(12), others = 1.887(12), 1.909(13), 2.786(12), 2.796(12), 2.855(12). AgAuF4, like other AA'F-4 salts (A = Na-Rb; A' = Ag, Au), crystallizes in the KBrF4 structure type, SG I4/mcnn (140), Z = 4 with a = 5.79109(6), c 10.81676(7) Angstrom. SPDD gave (in Angstrom) four Au-III-F = 1.89(1) and eight Ag-I-F = 2.577(7). SPDD for AgAuF6 confirmed that it has the LiSbF6 structure, 15.0451(6) Angstrom. SG R (3) over bar, Z = 3, with a = 5.2840(2), c = 15.0451(6) Angstrom.