Effect of Pyrrolidinium Based Ionic Liquid on Thermo Physical and Electrochemical Properties of Binary Aqueous Solutions of Benzylamine and Benzamide at Different Equidistant Temperatures (288.15 K to 318.15 K)

Effect of pyrrolidinium-based ionic liquid (IL) (1-butyl-1-methyl pyrrolidinium iodide) on the volumetric, acoustic and electrochemical properties of aqua solutions of benzylamine and benzamide has been analyzed at equidistant temperature range (288.15 K to 318.15 K) using different techniques. Density (ρ) and sound speed (u) for five different molal compositions (0.001 mol kg⁻¹ to 0.009 mol kg⁻¹) of the IL has been measured in binary aqua solutions of benzyl amine and benzamide. Using the measured density and sound velocity data, volumetric and acoustic quantities viz., AMV (apparent molar volume, \(V_{\phi }\) $V_{\varphi }$ ), PMV (partial molar volumes, \(V_{\phi }^{0}\) $V_{\varphi }^0$ ), standard partial molar volume of transfer \((\Delta V_{\phi }^{0} )\) $(\mathrm{\Delta }{V}_{\varphi }^0)$ , partial molar isentropic compression ( \(K_{\phi ,s}^{0}\) $K_{\varphi ,s}^0$ ), apparent molar isentropic compression \(\left( {K_{\phi ,S} } \right)\) $\left(K_{\varphi ,S}\right)$ , and partial molar isentropic compression of transfer \((K_{\phi ,s}^{0} )\) $(K_{\varphi ,s}^0)$ have been calculated. Transfer parameters were also determined and further used for the computation of pair and triplet interaction coefficients. The ion–solvent interactions have also been analyzed from conductance studies. Cyclic Voltammetry (CV) studies were further performed to investigate the electrochemical properties of the ternary mixtures for exploring their applications in different energy storage devices. The experimental results were also used to predict the structural behavior of the IL in aqueous benzylamine/benzamide solutions. Additionally, FTIR (Fourier Transformation Infrared Spectroscopy) and DFT (Density Functional Theory) techniques using (B3LYP)/6-311G++ (d, p) basis set of hybrid density functional theory was applied to the optimized geometrical structure of the ionic liquid using the Gaussian 09 program.