Density, viscosity, DFT and FTIR study of tertiary butyl alcohol and ethanol with DMSO and DMF at room temperature

Abstract

In this work, we report a combined experimental density, viscosity, FTIR and theoretical density functional theory (DFT) method of tertiary butyl alcohol (TBA)+dimethyl sulphoxide (DMSO), ethanol (ET)+DMSO, TBA+(dimethyl formamide) DMF, ET+DMF mixtures at room temperature. Density and viscosity data over the entire composition range have been used to compute excess molar volumes and deviation in viscosity, respectively. The excess molar volume (<em>V</em>^E) is negative for whole composition range for both systems, DMF+ET, DMF+TBA. The negative values of <em>V</em>^E indicate of the important interaction between unlike molecules. The deviation in viscosity (∆η) is positive over whole composition range for DMF+ET and negative for the DMSO+ET, DMSO+TBA and DMF+TBA. The negative ∆η suggests the forces between pairs of unlike molecules are less than the forces between like molecules. The molecular geometry, harmonic vibrational frequencies, Mulliken atomic charges have been calculated by using DFT theory/B3LYP method with 6-31G(d) basis set. Energies of HOMO-LUMO predict the strength and stability of complexes.