Diversity of Metal-Fullerene Framework Structures Regulated by Metal Salts

Taking into account the diversity of fullerene ligands and metal salts, metal-fullerene frameworks (MFFs) present a variety of structures. Currently, the structural control of MFFs mainly relies on the design and synthesis of fullerene ligands, while the influence of metal building units on the structures has been rarely studied. The present work represents a systematical investigation of fullerene-linked supramolecular architectures incorporating different metal salts. Treatment of a bidentate N,N-donors fullerene ligand (L1) with six metal salts ([Zn(NO3)(2)center dot 6H(2)O, Cd(NO3)(2)center dot 4H(2)O, Cu(NO3)(2)center dot 3H(2)O, Cu(OAc)(2)center dot H2O, FeCl2 center dot 4H(2)O and FeCl3 center dot 6H(2)O]) produced six one-dimensional MFFs, i.e., ZnL1(NO3)(2)(H2O)(2) (1), CdL1(NO3)(2) (2), Cu(L1)(H2O)(2)(NO3)(2) (3), CuL1(OAc)(CH3O) (4), FeL1Cl(2) (5) and FeL1Cl(2)(FeCl4) (6). Compounds 1-3, built with nitrates with different metal centers (M(NO3)(2), M = Zn, Cd, Cu), present a 1D stair-like, 1D zigzag, and 1D linear chain structure, respectively. Compound 4, synthesized with another Cu(II) salt, Cu(OAc)(2), displays a dinuclear Cu-Cu connected 1D stair-like chain structure, rather than the single Cu linked 1D linear chain obtained from Cu(NO3)(2). Compounds 5 and 6, assembled from iron chloride of different oxidation states (Fe(II)Cl-2 and Fe(III)Cl-3) reveal a 1D zigzag and a 1D stair-like chain structure, respectively. The results demonstrate the significant influences of metal salts on the structures of metal-fullerene frameworks.