Coordination Polymers of Hexacyanotrimethylenecyclopropanediide and Its Monoanionic Radical: Synthesis, Structure, and Magnetic Properties

The first examples of polymeric complexes that contain the polynitrile dianion hexacyanotrimethylenecydopropanediide (HCTMCP2-) were isolated and their magnetic properties have been explored. Complexes of the form (n-TBA)(2)[M(HCTMCP)(2)(H2O)(2)] (1) (M = Mn-II, Fe-II, Co-II, Cd-II) possess (4,4) sheet structures with large cavities that contain the tetra-n-butylammonium (n-TBA) countercations. Synthesis using sodium as the countercation yields a family of products with the general form [M(S)(4)M(S)(2)(HCTMCP)(2)] (S = EtOH, M = Fe-II (2); S = MeOH, M = Co-II or Zn-II (3)), These complexes adopt a variety of two-dimensional (2D) structures. The complex [Mn-3(HCTMCP)(2)(H2O)(12)](HCTMCP)center dot 6(H2O) (4) contains cationic (6,3) sheets with the counteranion and solvent molecules encapsulated within the hexagonal windows. Complexes 1-4 display weak antiferromagnetic coupling in all cases. The first example of a complex that contains the CN-coordinated monoanionic radical HCTMCP center dot-, [Cu(HCTMCP)(MeCN)(2)] (5) is described. This one-dimensional (1D) coordination polymer, containing tetrahedral Cu-I centers, displays medium strength antiferromagnetic coupling that is mediated through pi-interactions between the radical anions on adjacent chains.