The thermodynamic parameters viz. excess molar volume V-E and speed of sound u, transport parameter viscosity eta, and spectroscopic parameters viz. i.r., H-1 and C-13 n.m.r. have been determined for the mixtures of alpha,omega-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 Q(i)(E), isentropic compressibility K-S(E), viscosity deviation Delta eta, deviation in Gibbs free energies of activation for viscous flow g(x) and excess n.m.r. chemical shift delta(E) have been estimated and analyzed. The results reveal distinctly that the interaction between unlike molecules takes place through hydroxyl groups of alpha,omega-alkanediols and > CO group of pyrrolidin-2-one. An excellent correlation between thermodynamic and spectroscopic measurements has been observed. (c) 2007 Elsevier Ltd. All rights reserved.