Structural characterization and physicochemical features of new coordination polymer homopiperazine-1,4-diium tetrachlorocadmate(II)

Abstract

The present paper reports the synthesis of a new organic-inorganic hybrid compound, homopiperazine-1,4-diium tetrachlorocadmate(II) (C5H14N2)CdCl4, by slow evaporation method at room temperature. The single crystal X–ray diffraction proves that it crystallizes in the P21/n monoclinic space group with the following cell parameters: a = 5.910(5) Å, b = 16.476(3) Å, c = 12.605(3) Å, β = 97.26(4)°, V = 1217.7(11) Å3, Z = 4. Its atomic arrangement can be described as an alternation of organic and inorganic layers along the b-axis. The crystal packing was governed by the N-H⋯Cl intermolecular interactions between the (C5H14N2)2+ cations and the one dimensional polymeric {[CdCl3(μ3-Cl)3]2-}n anions. The powder X-ray diffraction confirms the phase purity. The three-dimensional Hirshfeld surface (3D-HS) analysis and the two-dimensional fingerprint plots (2D-FP) reveal that the structure is dominated by H⋯Cl/Cl⋯H and H⋯H contacts. The functional groups present in the crystal were studied by FTIR spectroscopy. Furthermore, the optical and PL properties of the compound were investigated in the solid state at room temperature and correlated to the HOMO-LUMO gap.