Self-assembly of a CuTIM(S2O7) polymer: synthesis and crystallographic studies

A novel self-assembled polymer of Cu(TIM)+2 (where TIM=Me4[14]1,3,8,10-tetraeneN4, a macrocyclic ligand) with disulfate bridges has been synthesized and investigated by X-ray crystallography, IR, electronic and ESR spectroscopy. The compound crystallizes in the monoclinic space group C2/c with cell parameters a=16.745(4), b=7.4288(13), c=16.657(4) Å, β=115.789(19)°. The coordination geometry around the Cu(II) center is axially elongated distorted octahedral. The basal plane around the Cu center is planar with zero deviation from the weighted least square plane comprising four nitrogen atoms (N1, N2, N1′ and N2′) of the macrocyclic ligand. Two axial positions are occupied by the O atoms of the S2O7 2− molecules. The Cu⋯Cu distance is quite long (8.328 Å) along the chain. The X-band ESR spectra of a powdered solid sample of [CuTIM(S2O7)]n polymer, recorded at room temperature gives a isotropic spectrum with a g value of 2.22.