Effect of Pressure on the Anisotropic Reorientation of Acetonitrile-d3 in the Liquid State

The deuteron and nitrogen spin–lattice relaxation times of acetonitrile-d3 have been measured as a function of pressure up to 2 kbar at 23°C using the NMR pulse method. Since the quadrupole coupling constants for nitrogen and deuterons in acetonitrile-d3 are known, the experimental T1 data were interpretable in terms of the rotational diffusion constants for motion perpendicular and parallel to the symmetry axis, D⊥ and D‖, respectively. In agreement with our previous results the calculated activation volumes show that ΔV‡(D⊥) is much larger than ΔV‡(D‖).