Thermo-physical properties of 1,3-Diaminopropane + alkyl acetate (C1-C4) liquid mixtures: Investigation of molecular interactions by insight of IR spectroscopy and DFT studies

Abstract

The density (ρ) and speed of sound (u) data of 1,3-Diaminopropane (1,3-DAP) (1) + alkyl acetate (AAc) (C1-C4) (2) mixtures at the temperatures (298.15, 303.15, 308.15, 313.15, and 318.15) K and pressure 0.1 MPa were measured. ρ and u data have been used to calculate excess molar volume (VmE), excess molar isentropic compressibility (ksE), excess ultrasonic speed (uE), excess free volume (VfE), excess available volume (VaE) and excess intermolecular free length (LfE). The result of speed of sound have been analyzed in term of various correlations like Nomoto, Van Dael, Impedance dependence and Schaaff's collision factor theory at temperature 298.15 K. The calculated deviation and excess properties are well fitted with Redlich-Kister polynomial equation and further results were analyzed with the help of the structural, inter and intramolecular interaction aspects. IR spectra of the liquid mixture supported the intermolecular interaction between the 1,3-DAP and AAc molecules through shifting of the position of the stretching frequency of some specific functional groups. The results obtained from DFT studies clearly indicates the formation of strong intermolecular interaction between 1,3-DAP and AAc.