title: Synthesis and Characterization of Novel V/O/SO(4) Chains Incorporating 2,2'-Bipyridine Ligands: Crystal Structure of [V(2)O(2)(OH)(2)(SO(4))(2,2'-bpy)(2)].
abstract: The hydrothermal reaction of a mixture of vanadyl acetylacetonate (VO(acac)(2)), Na(2)SO(4), 2,2'-bipyridine (2,2'-bpy), and H(2)O for 48 h at 160 degrees C gives brown crystals of [V(2)O(2)(OH)(2)(SO(4))(2,2'-bpy)(2)] (1) in 70% yield. The structure of 1 consists of ribbons constructed from the infinite inorganic chains, [-{V(2)O(2)(OH)(2)}-&mgr;(2)-SO(4){V(2)O(2)(OH)(2)}-SO(4)](infinity), incorporating organic (2,2'-bipyridine) ligands. The inorganic chains are composed of the pairs of edge-sharing octahedra joined by {SO(4)} tetrahedra through octahedral-tetrahedral corner sharing. The octahedral geometry around each vanadium(IV) ion is defined by {VO(2)(OH)(2)N(2)} with each V(IV) center coordinated to a terminal oxo group, two &mgr;(2)-OH groups, two nitrogen donor atoms from a chelating 2,2'-bipyridine ligand, and an oxygen donor atom from a &mgr;(2)-SO(4)(2)(-) ligand. Crystal data for 1: monoclinic space group P2(1)/n (No. 14), a = 11.7937(2) Å, b = 12.1161(3) Å, c = 15.5763(2) Å, beta = 93.750(2) degrees, Z = 4. 1 constitutes the first example of a fully reduced vanadosulfate (V/O/SO(4)) based solid incorporating both the organic and inorganic ligands. The novel solid exhibits Curie-Weiss paramagnetism at high temperature (T > 140 K) and short-range antiferromagnetic coupling between the V(IV) centers at lower temperature.
authors.affiliation: Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, Chicago, Illinois 60616, Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, and Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148.
authors.forename: M. Ishaque
authors.initials: MI
authors.lastname: Khan
authors.forename: Sabri
authors.initials: S
authors.lastname: Cevik
authors.forename: Douglas
authors.initials: D
authors.lastname: Powell
authors.forename: Sichu
authors.initials: S
authors.lastname: Li
authors.forename: Charles J.
authors.initials: CJ
authors.lastname: O'Connor