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) 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.