Chlorine-35 NQR frequency and spin-lattice relaxation time measurements as a function of temperature in the range 77-300 K were carried out on 2-amino-3,5-dichloropyridine. Two NQR signals were observed and were assigned to the two chlorines present in the molecule using the additive model for subst
Temperature- and pressure-dependent study of 35Cl NQR frequency and spin lattice relaxation time in 2,3-dichloroanisole
✍ Scribed by L. Ramu; K. P. Ramesh; D. Ramananda; R. Chandramani
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 141 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0749-1581
- DOI
- 10.1002/mrc.2627
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The temperature and pressure dependence of ^35^Cl NQR frequency and spin lattice relaxation time (T~1~) were investigated in 2,3‐dichloroanisole. Two NQR signals were observed throughout the temperature and pressure range studied. T~1~ were measured in the temperature range from 77 to 300 K and from atmospheric pressure to 5 kbar. Relaxation was found to be due to the torsional motion of the molecule and also reorientation of motion of the CH~3~ group. T~1~ versus temperature data were analyzed on the basis of Woessner and Gutowsky model, and the activation energy for the reorientation of the CH~3~ group was estimated. The temperature dependence of the average torsional lifetimes of the molecules and the transition probabilities were also obtained.
NQR frequency shows a nonlinear behavior with pressure, indicating both dynamic and static effects of pressure. The pressure coefficients were observed to be positive for both the lines. A thermodynamic analysis of the data was carried out to determine the constant volume temperature coefficients of the NQR frequency. The variation of spin lattice time with pressure was very small, showing that the relaxation is mainly due to the torsional motions of the molecules. Copyright © 2010 John Wiley & Sons, Ltd.
📜 SIMILAR VOLUMES
## Abstract Carbon‐13 NMR spin–lattice relaxation times, __T__~1~, and nuclear Overhauser effect data were obtained for neat tetra‐__n__‐octyltin at 22.5 and 100.6 MHz over a wide temperature range. __T__~1~ values were also measured at 25.16 MHz at pressures up to 211 MPa. The ambient‐pressure dat
A 35Cl NQR study of 2-chloro-3-pyridinol showed the presence of four NQR signals at 77 K. One of the lines showed a positive temperature coefficient of the NQR frequency. 'HNMR studies showed the presence of intramolecular hydrogen bonding, and the anomalous NQR temperature dependence has been expla
The temperature and pressure dependences of 35 Cl nuclear quadrupole resonance (NQR) frequency and spin-lattice relaxation time (T 1 ) were investigated for 1-chloro-2,4-dinitrobenzene and 1,2-dichloro-3nitrobenzene. T 1 was measured in the temperature range 77-300 K. Furthermore, the NQR frequency