A comprehensive study of crystal structure, UV–visible study, electric-dielectric properties of a recently developed Hybrid Material [(C6H5N2)2ZnCl4]

Abstract

The advanced hybrid material, [(C6H5N2)2ZnCl4] was prepared using the gradual dehydration process by combining 4-cyanopyridine and ZnCl2 under standard ambient temperature conditions. The compound underwent various characterization techniques, including single crystal and Powder X-ray diffractions (SXRD, PXRD), Scanning Electron Microscopy (SEM) and EDX Energy-Dispersive X-ray, FT-IR spectroscopy, UV–Visible absorption analysis, Hirshfeld surface analysis (SHG), and thermal analysis. The molecular composition of the examined chemical substances was determined to belong to the orthorhombic P212121 space group through single crystal X-ray analysis. analysis. Its molecular arrangement was characterized by alternating layers of tetrahedral [ZnCl4]2- and 4-cyanopyridinium planes (C6H5N2)+. These layers are connected through NH···Cl and CH···Cl hydrogen bonds, which contribute to their cohesion and overall adherence. The UV–visible spectrum using Tauc plot relation, has unveiled the energy ratio of an optical band gap, which is measured at 4.80 eV. Additionally, thermal analysis has demonstrated that [(C6H5N2)2ZnCl4] exhibits thermal stability up to a temperature of 475 K. SHG study was employed to examine the interactions between molecules. Additionally, 2D finger plots were utilized to quantitatively assess the impact of these interactions on the crystal structure. This work discusses various electrical characteristics obtained through impedance measurements, including dielectric constants and electric modulus. To shed light on the electrical resistance and dielectric characteristics, we conducted complex impedance spectroscopy at different frequencies with temperature ranging between 313 and 423 K. The elaborate Nyquist curve revealed a solitary semicircle, indicating that the signal was generated by a single capacitive circuit associated with the grain. We also researched ac conduction to figure out how electricity is transmitted. The diagram unveils that the conduction mechanism is thermally activated. The activation energy value obtained from the dc conductivity is approximately 0.768 eV. The analysed material allows for the movement of space charge through a hopping mechanism. Finally, the dielectric constant estimate demonstrates that this title compound is a suitable candidate for the fabrication of opto-electronic materials. Modulus analysis demonstrated that the mobile charge carriers exhibited mobility both at low and high frequencies, covering short and long distances.