Synthesis, structure and dielectric properties of a Cd coordination polymer based on homopiperazine

A (4,6)-connected three-dimensional network complex [Cd(hpip)Br2]n (1) [hpip = homopiperazine] was prepared from CdBr2·4H2O and hpip by hydrothermal reaction in water. The structure was characterized by single-crystal X-ray diffraction (XRD), Fourier transform infrared spectroscopy, thermogravimetric analysis and elemental analysis. The asymmetric unit contains one hpip ligand, one Cd(II) cation and two Br− anions. Each Cd(II) cation is coordinated by two N atoms from the ligand and four Br− anions, showing a distorted octahedral geometry. Its dielectric constant was measured at different frequencies with temperature variations.