Quadrupole Resonance Study of Molecular Motion in Solid Hydrazine

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Abstract
Linewidths and spin–lattice relaxation times of the six nuclear quadrupole resonance lines of 14N in hydrazine were measured from 200° to 260°K using pulse technique. Cross-relaxation (Overhauser) experiments between corresponding transitions at the two sites were also performed. It is shown that in this temperature range the dominant relaxation mechanism is a molecular motion which interchanges nuclei between the two inequivalent crystallographic sites. A detailed analysis of the cross-relaxation experiment and of the anisotropies in spin–lattice relaxation leads to a determination of the relative orientation of the principal axes system of the field-gradient tensors at the two sites. The molecular motion has an activation energy of 14.3 ± 0.4 kcal/mole and a rate ∼ 2500 sec−1 at 250°K.