Solvent-free synthesis of a binary organic material with spectroscopic, thermodynamic, dielectric and computational studies

The synthesis of a novel schiff base, N, N’-(1,4-phenylene) bis[(4-chloropyridin-2-yl) methanimine], abbreviated as PCPMA, was achieved through a solid-state reaction. Phase-diagram analysis of the binary system revealed the formation of the PCPMA at a 1:2 stoichiometric ratio of parent compounds with two adjacent eutectics. The synthesized molecule exhibited a significantly higher melting point relative to the parent compounds. Spectroscopic studies, both experimental and simulated, validate the formation of the imine bond between the parent compounds. Thermodynamic studies, such as heat of mixing, entropy of fusion, roughness parameter, interfacial energy, and excess thermodynamic functions of eutectics and PCPMA, were calculated based on the heat of fusion values. Additionally, hybrid computational calculations for geometry relaxation and spectral parameters were conducted using DFT (B3LYP) methods with the 6-311 + + G(d, p) basis sets. DFT calculations revealed a semiconducting nature in the electronic structure of PCPMA. This observed semiconductor behaviour, coupled with a high dielectric constant, suggests its promising applications in organic electronics and memory devices.