where the longer N-to-N distance in bpp can lead to larger cavities in coordination networks, and different conformations of bpp can result in different extended structures. The interaction in the system Cu(BF4)2–bpp resulted in a new 1D coordination polymer with the composition {[Cu(bpp)2(H2O)](BF4)2·(dmf)·2(H2O)}n I, and complex was studied by IR spectroscopy, TGA analysis and the single crystal X-ray diffraction method. The IR spectrum confirms the presence of the organic ligands used in the synthesis. Vibrations of the aromatic ring in I were registered as the band of average intensity at 1655 cm-1, and for coordinated water molecule at 3246–3116 cm-1. The compound I crystallizes in non-centrosymmetric monoclinic P21 space group. The copper atom adjusts the square-pyramidal coordination surrounding composed by four bpp nitrogen atoms and one water oxygen atom. The bpp ligand is linked to the Cu(II) atoms in a double-stranded bridge fashion, thus extending the structure to 1D double tape composed of the 24-membered metallo-ring with Cu···Cu separation of 11.475 Å across the cavity. The hydrophilic regions absorb [BF4]anions, water and dmf molecules, and are held in the crystal lattice via OH···O and OH···F hydrogen bonds (Figure 1a). (a) The decomposition of I was investigated by combined TG-DTA (Figure 1b). The first weight loss step is observed in the range of 47-89°C, corresponding to the removal of three molecules of water and accompanied by a weak endothermic effect with a 7.26% (7.08% calc.) mass loss. Subsequent heating leads to the loss of a dmf molecule from the outer sphere, with mass loss accounting for 8.37% (9.59% calc.). Beginning at 150°C, a new mass loss is observed, which corresponds to the removal of two BF4 anions with a 22.86% loss of mass (22.86% calc.). In the range of 347-680°C degradation of the bpp ligand takes place, the process being strongly exothermic with a maximum at 522°C. The mass fraction of the obtained residue corresponds to CuO, representing 10.91% (10.51% calc.).