Proton spin – lattice relaxation time of aniline-d2 in deuterated benzene and deuterated aniline solution

Abstract

The proton spin – lattice relaxation time of aniline-d2 in deuterated aniline solution was determined as a function of concentration and temperature over the temperature interval 260–360 °K using a pulsed nuclear magnetic resonance technique. In addition the proton spin – lattice relaxation time of aniline-d2 in deuterated benzene solution at 20 °C was also determined. It was found that the activation energies of the intra- and inter-molecular relaxation rates were of similar magnitude, viz. 4.5 and 4.4 kcal/mole, respectively. It was also found that at 20 °C the rotational correlation time, τr, of the C6H5NH2 molecule in infinitely dilute perdeutero benzene solution was approximately half that of the partially deuterated aniline molecule, viz. 3.0 × 10−12 and 6.3 × 10−12 s, respectively, and that τr of C6H5ND2 in infinitely dilute perdeutero aniline solution is much larger than in infinitely dilute perdeutero benzene solution and is equal to 19 × 10−12 s.