title: Formation of a solubilized cobalt block oligomer from a M2L-type double helicate.
abstract: The multi-dentate ligand, 2,3,5,6-tetrakis(2,2'-bipyridyl)pyrazine (L) and divalent cobalt self-assemble to a block co-polymer-like oligomer in solution, which contains at least the L(7)Co(8) fragment. The extent of oligomerization is sensitive to the water content in acetonitrile solution. In the solid state, the simple monomer [LCo(2)(CH(3)CN)(4)][ClO(4)](4) is isolated. The X-ray structure of the crystallized material (containing four CH(3)CN solvate molecules) reveals a double-helical complex with two heptadentate Co(II) sites, and a helical pitch of approximately 28.1 A. Coupled Co(I/II) redox processes are observed between the two metal centres.
authors.affiliation: Chemical Laboratory, University of Kent, Canterbury, Kent, UKCT2 7NJ.
authors.forename: Fenton
authors.initials: F
authors.lastname: Heirtzler
authors.forename: Saverio
authors.initials: S
authors.lastname: Santi
authors.forename: Kevin
authors.initials: K
authors.lastname: Howland
authors.forename: Thomas
authors.initials: T
authors.lastname: Weyhermüller
mesh_terms: D001665:Binding Sites; D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008968:Molecular Conformation; D011108:Polymers / Q000737:chemistry*; D012995:Solubility; D014867:Water
chemical_list: D011108:Polymers; D014867:Water; D003035:Cobalt