On the high-temperature phase transition of a new chlorocadmate(ii) complex incorporating symmetrical Cd2Cl6 clusters: structural, optical and electrical properties

Hanen Elgahami; Abderrazek Oueslati; Samia Nasr; Ferdinando Costantino; Houcine Naïli

doi:10.1039/d3ra04289h

On the high-temperature phase transition of a new chlorocadmate(ii) complex incorporating symmetrical Cd₂Cl₆ clusters: structural, optical and electrical properties

RSC Adv. 2023 Sep 5;13(37):26122-26133. doi: 10.1039/d3ra04289h. eCollection 2023 Aug 29.

Authors

Hanen Elgahami¹, Abderrazek Oueslati¹, Samia Nasr², Ferdinando Costantino³, Houcine Naïli⁴

Affiliations

¹ Laboratory of Spectroscopic Characterization and Optical Materials, Faculty of Sciences, University of Sfax B.P. 1171 Sfax 3000 Tunisia hanengahami1993@gmail.com.
² Chemistry Department, Faculty of Science, King Khalid University P.O. Box 9004 Abha 61413 Saudi Arabia.
³ Department of Chemistry Biology and Biotechnologies, University of Perugia Via Elce di Sotto 8 Perugia 06123 Italy.
⁴ Laboratory Physico Chemistry of the Solid State, Department of Chemistry, Faculty of Sciences, University of Sfax BP 1171 Sfax 3000 Tunisia houcine.naili@fss.rnu.tn.

Abstract

In the present investigation, a new hybrid crystal, with the formula [(C₄H₉)₄P]₂Cd₂Cl₆ has been synthesized by the slow evaporation method at room temperature. It was characterized by X-ray diffraction (XRD), Hirshfeld surface, differential scanning calorimetry (DSC), optical measurement and complex impedance. Single crystal X-ray diffraction structural analysis revealed that the title compound crystallizes in the triclinic system with space group P1̄ and cell parameters: a = 11.972 (1) Å, b = 15.418 (1) Å, c = 15.426 (2) Å, αa = 68.71 (2) °, β = 73.20 (3) ° and γ = 74.39 (2)°. The Hirshfeld surface analysis was conducted to investigate intermolecular interactions and associated 2D fingerprint plots, revealing quantitatively the relative contribution of these interactions in the crystal cohesion. DSC studies indicated one phase transition at about 348 K. Optical absorption spectra show that the band gap of [(C₄H₉)₄P]₂Cd₂Cl₆ is approximately 2.65 eV. The Nyquist plot showed only one semicircular arc, representing the grain effect in the electrical conduction. The thermal evolution of the conductivity of the grains presents an Arrhenius type behavior, demonstrating that charge carriers have to overcome different energy barriers while conducting and relaxing. Besides, the AC conductivity was analyzed by Jonscher's law and the conduction mechanism is well ensured by the correlated barrier hopping (CBH) model.