A two-dimensional deuterium nuclear magnetic resonance study of molecular reorientation in sugar/water glasses

Two-dimensional nuclear magnetic resonance time domain analysis of the stimulated echo experiment is used to study the molecular reorientation of deuterated glucose molecules in a glucose/water glass at about 15 °C above the glass transition. By measuring both the cos–cos and sin–sin two-time single particle correlation functions it is shown that the reorientation is isotropic, which enables the determination of the relaxation time T1Q and the rotational correlation time. By fitting the cos–cos and sin–sin correlation functions with a modified Kohlrausch–Williams–Watts (KWW) function and comparing the resulting parameters with simulations, it is shown that the reorientation is dominated by small angle jumps (≈3°), but there is also a small fraction of large angle (≈34°) jumps present.