Molecular interactions of α,ω-alkanediols in pyrrolidin-2-one: Thermophysical and spectroscopic measurements

The thermodynamic parameters viz. excess molar volume VE and speed of sound u, transport parameter viscosity η, and spectroscopic parameters viz. i.r., 1H and 13C n.m.r. have been determined for the mixtures of α,ω-alkanediols (1,2-ethanediol, 1,3-propanediol, and 1,5-pentanediol) and pyrrolidin-2-one over the whole composition range at T = 308.15 K. The partial molar quantities QiE, isentropic compressibility KSE, viscosity deviation Δη, deviation in Gibbs free energies of activation for viscous flow g(x) and excess n.m.r. chemical shift δE have been estimated and analyzed. The results reveal distinctly that the interaction between unlike molecules takes place through hydroxyl groups of α,ω-alkanediols and CO group of pyrrolidin-2-one. An excellent correlation between thermodynamic and spectroscopic measurements has been observed.