Computational and experimental study of molecular interaction in a ternary liquid mixture of cyclohexylamine+ethanol+benzene

Abstract

In the present investigation, we undertake the study of molecular interaction in a ternary mixture of cyclohexylamine (CHA), ethanol (Eth) and benzene (B) theoretically as well as experimentally. We study the interaction between CHA dimer and complexes (Eth-CHA, B-CHA, CHA-Eth-B) theoretically using DFT (Density functional theory) in gas phase. It includes the quantum chemical calculations of interaction energy, bond length, and identification of the intermolecular interaction from structural parameter analysis and molecular orbital analysis. Further, we experimentally determine the excess thermo-acoustic parameters of the mixture. For this, we have measured the ultrasonic velocity (u) and density (ρ) of the ternary mixture of CHA+Eth+B and of pure components at 303 K, 308 K and 313 K temperature. From these experimental values of u and ρ, excess thermo-acoustic parameters have been estimated using standard relations. The variations in excess acoustic parameters with the concentration of CHA (x1) are discussed in terms of the interactions and molecular geometry of the liquid mixture. At lower concentration, weak interactions dominate while on increasing x1 strong forces between molecules take place. The strong H-bonding interaction between CHA-ethanol molecules and molar volume differences of pure components leads to interstitial accommodation of molecules. The experimentally determined excess properties behaviour is supported by the theoretical calculation.