title: Structures of M2(SO2)6B12F12(M = Ag or K) and Ag2(H2O)4B12F12: Comparison of the Coordination of SO2versus H2O and of B12F122-versus Other Weakly Coordinating Anions to Metal Ions in the Solid State.
abstract: The structures of three solvated monovalent cation salts of the superweak anion B12F122-(Y2-), K2(SO2)6Y, Ag2(SO2)6Y, and Ag2(H2O)4Y, are reported and discussed with respect to previously reported structures of Ag+and K+with other weakly coordinating anions. The structures of K2(SO2)6Y and Ag2(SO2)6Y are isomorphous and are based on expanded cubic close-packed arrays of Y2-anions with M(OSO)6+complexes centered in the trigonal holes of one expanded close-packed layer of B12centroids (⊙). The K+and Ag+ions have virtually identical bicapped trigonal prism MO6F2coordination 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)6+complex is connected to three other cationic complexes through their six μ-SO2-κ1O,κ2O' ligands. The structure of Ag2(H2O)4Y is unique [different from that of K2(H2O)4Y]. 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-H2O)2Ag(μ-H2O)2)]∞infinite chains between the planes of anions. There are two nearly identical AgO4F2coordination 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 H2O molecules coordinated to a Ag+ion in the solid state. Comparisons with crystalline H2O and SO2solvates of other Ag+and K+salts of weakly coordinating anions show that (i) N[(SO2)2(1,2-C6H4)]-, BF4-, SbF6-, and Al(OC(CF3)3)4-coordinate much more strongly to Ag+than does Y2-, (ii) SnF62-coordinates somewhat more strongly to K+than does Y2-, and (iii) B12Cl122-coordinates to K+about the same as, if not slightly weaker than, Y2-.
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin , 14195 Berlin, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Malischewski
authors.affiliation: Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States.|Department of Chemistry and Biochemistry, University of South Carolina , Columbia, South Carolina 29208, United States.
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Peryshkov
authors.affiliation: Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Eric V
authors.initials: EV
authors.lastname: Bukovsky
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin , 14195 Berlin, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Seppelt
authors.affiliation: Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Strauss