35 Cl Nuclear Quadrupole Resonance Studies of Molecular Motions of the CIO3− Ion in RbCIO3

Abstract

The 35Cl NQR frequency (VQ) and spin‐lattice relaxation time (T1Q) for polycrystalline RbClO3 are measured in the temperature ranges 77 to 445 K and 296 to 445 K, respectively. The observed decrease in the resonance frequencies with increasing temperature permits the determination of the libration frequencies of the ClO 3− ion about two axes perpendicular to the threefold axis of the ion. The experimentally obtained temperature dependence of T1Q suggests two mechanisms in the nuclear quadrupole relaxation process. Librational motions are found to be responsible for the shortening of T1Q up to 330 K, whereas above this temperature hindered rotation of the ClO 3− anion proves to be dominant.

35Cl NQR studies of 1‐chloro‐2,4‐dinitrobenzene and 1,2‐dichloro‐3‐nitrobenzene as a function of pressure and temperature

“…Both of these motions can cause fluctuations in the EFG. In such a case, the effective relaxation rate will have contributions from the torsional oscillations as well as from the reorientation of the molecular groups and will have the form 19 1…”

Caesium and hydrated lead chlorates studied by35Cl NQR spectroscopy

“…So far a large number of compounds from the groups of chlorates [1][2][3][4] have been studied by 35 C1 nuclear quadrupole resonance (NQR) spectroscopy, and for selected compounds the molecular dynamics has been studied as well. The available literature data on 35 C1 NQR (the resonance frequency 35 Cl NQR at the liquid nitrogen temperature or the lowest studied temperature and for the sake of comparison at ambient temperature, quadrupole coupling constant, asymmetry parameter and Tt relaxation time) are collected in Table 1.…”

“…1. It has been established that for the so far studied sodium, barium [1,2], rubidium and caesium [3,4] chlorates the increase in the relaxation rate is a result of the onset of the hindered rotation of the chlorate ion about the threefold axis. The aim of this study was to study the dynamics of caesium and lead chlorates and to compare the results with the data for other compounds from this group.…”