Synthesis, crystal structure, Hirshfeld surface analysis and dielectric properties of a new centrosymmetric hybrid compound (C4H12NO3)CdCl3·H2O

Abstract

A new organic–inorganic hybrid centrosymmetric compound, (C4H12NO3)CdCl3·H2O, was synthesized by the slow evaporation method at room temperature and characterized by single X-ray diffraction (SCXRD). The results of the X-ray diffraction study demonstrated that this material crystallizes in the triclinic system with the space group P1¯ and the following unit cell parameters a = 6.822(6) Å, b = 8.96(2) Å, c = 10.034(3) Å, α = 72.901(3)°, β = 71.927(3)°, γ = 89.099(3)° and Z = 2. In the crystal structure, the atomic arrangement is described as an alternation of organic and inorganic layers along the a-axis. The anionic layers are formed by [CdCl5O]− octahedrons, while the cationic layers are made up of [C4H12NO3]+ cations. The crystal packing is governed by NH⋯Cl, NH⋯O, CH⋯Cl, OH⋯Cl and OH⋯O hydrogen bonds, forming a three dimensional supramolecular network. Hirshfeld surfaces and 2D fingerprint plots were determined for visualizing, exploring and quantifying the intermolecular interactions in the crystal lattice of the title compound. Infrared and Raman spectroscopy were reported at room temperature in the frequency domains 400–4000 cm−1 and 50–500 cm−1, respectively. Differential scanning calorimetry (DSC) revealed one exothermic peak located at around T1 = 368 K. Electrical and dielectric properties were investigated as a function of temperature (300–430 K) in the frequency range 40 Hz–110 MHz. The electrical and dielectric studies were performed by means of impedance spectroscopy and dielectric permittivity ε',ε''. Nyquist curves were well fitted to an equivalent circuit formed by parallel combination resistance and capacity fractal of the bulk. The frequency dependence of the alternative current (AC) conductivity was analyzed using the Jonscher law. Overlapping-large polaron tunneling (OLPT) and non-overlapping small polaron tunneling (NSPT) conduction mechanism models successfully explained the behavior of the exponent n.