Synthesis, Crystal Structure, Hirshfeld Surfaces, Spectroscopic, Thermal and Dielectric Characterizations for the New Hybrid Material (C7H11N2)2ZnI4

Abstract

Bis[4-(dimethylamino)pyridinium]tetraiodozincate(II), formulated as (C₇H₁₁N₂)₂ZnI₄, is a novel organic–inorganic hybrid material that is the subject of this study’s synthesis, structural evaluation and functional characterization. The material was prepared at room temperature by the slow evaporation method and crystallized having space group C2/c in the monoclinic system. The following cell parameters are a = 11.0502(3) Å, b = 13.0289(3) Å, c = 17.3038(5) Å, β = 103.896(3)°, V = 2418.35(12) ų with four formula units. The structural analysis highlights alternating inorganic layers positioned at z = 1/4 and z = 3/4, with organic cations occupying the regions at z = 0 and z = 1/2. The stability of the structure is ensured through N–H···I hydrogen bonding interactions. Furthermore, Hirshfeld surface analysis confirms that the dominant intermolecular interactions within the structure are H···H and I···H contacts, emphasizing the role of these interactions in maintaining cohesion and stability. A phase transition is detected at 369 K by thermal investigation, which is corroborated by electrical and dielectric measurements. Semicircular arcs defined by a Cole–Cole model were discovered by impedance spectroscopy recorded between 313 and 373 K in the frequency range of 40 Hz to 10 MHz. The Arrhenius type behavior is exhibited by the thermal conductivity. The title compound exhibited a relaxation phenomenon and notable protonic conduction, indicating its potential for applications in hybrid materials with advanced electrical properties.