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

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) with B3LYP/6-311++G(d,p) level theory in a gas phase. It includes the quantum chemical calculations of interaction energy, bond length, and identification of the intermolecular interaction from structural parameter 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 cyclohexylamine+ethanol+benzene and of pure components at 303, 308 and 313 K temperature. From these experimental values of u and ρ, excess thermo-acoustic parameters have been estimated using standard relation. The variations in excess acoustic parameters with the concentration of cyclohexylamine (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. Experimentally determined excess properties behaviour is supported by the theoretical calculation