Supramolecular cobalt cages and coordination polymers templated by anion guests: Self-assembly, structures, and magnetic properties

We report the anion-templated syntheses of a variety of supramolecular assemblies of Co-II. Remarkably in the presence of a weakly coordinating ion such as BF4-, a discrete three-dimensional cage [BF4 subset of(BF4)(2)Co-2(L-1)(4)][BF4] (2) is formed with three coordinated BF4- ions, a rare example in supramolecular chemistry (L-1 = di(benzimidazole)-1,4-phenylene). Switching to stronger coordinating ions, such as NO3- or Cl-, a one-di-mensional coordination polymer [{Co(L-1)(NO3)(2)}(n)] (3) and a metallomacrocycle [Co-2(L-1)(2)(Cl-4] (5) were formed, respectively. These results illustrate the powerful effect of the anion-templating chemistry. Finally the magnetic properties of these assemblies 1b, 2, 3, and 5 are presented and discussed.