Effect of intermolecular interactions on the anisotropic rotational motions of molecules. 1H, 2H and 14N nuclear magnetic resonance relaxation study of the acetonitrile–chloroform liquid system

Abstract

² H and ¹⁴N spin–lattice relaxation times for the CD₃CN and CDCl₃ molecules in the CD₃CN–CDCl₃ liquid system have been determined at temperatures between 250 and 315 K. Analyses of these data led to the determination of rotational diffusion coefficients about the C₃ symmetry axis (D‖) and around the axes perpendicular to the symmetry axis (D_⊥). Anisotropy of the rotational motions (D_‖/D_⊥) of CD₃CN increases upon addition of CDCl₃ to CD₃CN liquids and reaches maxima at the mole fraction of CDCl₃ to CD₃CN liquids and reaches maxima at the mole fraction of CDCl₃ to CD₃CN liquids and reaches maxima at the mole fraction of CDCl₃[x(CDCl₃)]= 0.8. Slowing down of the rotational motions of CDCl₃ is also observed, and reaches minima at x(CDCl₃)= 0.6–0.7.