Structures of M 2 (SO 2 ) 6 B 12 F 12 (M = Ag or K) and Ag 2 (H 2 O) 4 B 12 F 12 : Comparison of the Coordination of SO 2 versus H 2 O and of B 12 F 12 2- versus Other Weakly Coordinating Anions to Metal Ions in the Solid State

• Published in: Inorganic chemistry 2016-12, Vol.55 (23), p.12254-12262
• Main Authors: Malischewski, Moritz, Peryshkov, Dmitry V, Bukovsky, Eric V, Seppelt, Konrad, Strauss, Steven H
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.6b01980

The structures of three solvated monovalent cation salts of the superweak anion B F (Y ), K (SO ) Y, Ag (SO ) Y, and Ag (H O) Y, are reported and discussed with respect to previously reported structures of Ag and K with other weakly coordinating anions. The structures of K (SO ) Y and Ag (SO ) Y are isomorphous and are based on expanded cubic close-packed arrays of Y anions with M(OSO) complexes centered in the trigonal holes of one expanded close-packed layer of B centroids (⊙). The K and Ag ions have virtually identical bicapped trigonal prism MO F coordination spheres, with M-O distances of 2.735(1)-3.032(2) Å for the potassium salt and 2.526(5)-2.790(5) Å for the silver salt. Each M(OSO) complex is connected to three other cationic complexes through their six μ-SO -κ O,κ O' ligands. The structure of Ag (H O) Y is unique [different from that of K (H O) Y]. Planes of close-packed arrays of anions are offset from neighboring planes along only one of the linear ⊙···⊙···⊙ directions of the close-packed arrays, with [Ag(μ-H O) Ag(μ-H O) )] infinite chains between the planes of anions. There are two nearly identical AgO F coordination spheres, with Ag-O distances of 2.371(5)-2.524(5) Å and Ag-F distances of 2.734(4)-2.751(4) Å. This is only the second structurally characterized compound with four H O molecules coordinated to a Ag ion in the solid state. Comparisons with crystalline H O and SO solvates of other Ag and K salts of weakly coordinating anions show that (i) N[(SO ) (1,2-C H )] , BF , SbF , and Al(OC(CF ) ) coordinate much more strongly to Ag than does Y , (ii) SnF coordinates somewhat more strongly to K than does Y , and (iii) B Cl coordinates to K about the same as, if not slightly weaker than, Y .