Proton NMR Study of Molecular Dynamics in Hydrazinium Perchlorate

The proton spin-lattice relaxation time Tl (at 5.4, 10 and 15 MHz) and second moment M 2 (at 9.8 MHz) have been measured in hydrazinium Perchlorate (N 2 H 5 C10 4 ) . The temperature dependence of T, shows two minima. The low temperature T, minimum has been explained in terms of N H 3 reorientation about the N N axis while the high temperature minimum is attributed to the exchange of protons within the N H 2 group (180° flip about the H N H bisectrix). The activation energies for N H 3 and N H : motions are found to be 20.5 kJ m o l " 1 and 39.8 kJ mo l " 1 , respectively. The second moment variation u ith temperature shows two transitions around 120 K and 210 K and has been discussed in terms of N H 3 / N H 2 motions.