Journal ArticleDOI
Nuclear Pure Quadrupole Relaxation and Its Temperature Dependence in Solids
D. E. Woessner,H. S. Gutowsky +1 more
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TLDR
In this paper, the authors used a torsional molecular oscillator model to measure the T1 of the pure quadrupole T1 in cuprous oxide, paradichlorobenzene, 2,2-dichloropropane, t-butyl chloride, and methylene chloride at temperatures from 77°K to room temperature.Abstract:
The Cu63 and Cl35 pure quadrupole relaxation times have been measured by rf pulse techniques in cuprous oxide, paradichlorobenzene, 2,2‐dichloropropane, t‐butyl chloride, and methylene chloride at temperatures from 77°K to room temperature. The Cu63 T1 data agree with the ionic lattice model. The Cl35 T1 data for paradichlorobenzene agree with a torsional molecular‐oscillator model. For 2,2‐dichloropropane the Cl35 T1 values agree with a model based on field‐gradient fluctuations produced by reorienting CH3 groups. The more complicated T1 temperature dependences observed in t‐butyl chloride and methylene chloride appear to be the result of multiple thermal motions. The same can be said of our limited data on the Cl35 relaxation in 1,2‐dichloroethane. No discernible difference was found for the relaxation times of the two Cl35 resonance lines in methyl chloroform at 77°K.In general, the available proton T1 and linewidth data correlate well with our chlorine results; this agreement is discussed. The chlorine spin phase memory times are governed by the local magnetic fields except when decreased by spin—lattice lifetime broadening. The inverse linewidth parameters exhibit broadening by a distribution of field gradients. The fadeout of the Cl35 quadrupole resonance with increasing temperature in 2,2‐dichloropropane is the result of T1 broadening, while in t‐butyl chloride and methylene chloride it is produced by phase transitions.The Bayer model for spin—lattice relaxation by molecular torsional oscillations is treated in some detail, including a new approach which dispenses with some of his simplifying assumptions. A brief analysis is given of T1 for the case in which field‐gradient fluctuations are produced by random, large‐angle reorientations of groups near to the relaxed nucleus. The theory is presented for a null method of measuring the pure quadrupole T1. The method, which was used in most of our measurements, is similar to the Carr—Purcell 180°—90° pulse method for measuring nuclear magnetic T1's.The Cu63 and Cl35 pure quadrupole relaxation times have been measured by rf pulse techniques in cuprous oxide, paradichlorobenzene, 2,2‐dichloropropane, t‐butyl chloride, and methylene chloride at temperatures from 77°K to room temperature. The Cu63 T1 data agree with the ionic lattice model. The Cl35 T1 data for paradichlorobenzene agree with a torsional molecular‐oscillator model. For 2,2‐dichloropropane the Cl35 T1 values agree with a model based on field‐gradient fluctuations produced by reorienting CH3 groups. The more complicated T1 temperature dependences observed in t‐butyl chloride and methylene chloride appear to be the result of multiple thermal motions. The same can be said of our limited data on the Cl35 relaxation in 1,2‐dichloroethane. No discernible difference was found for the relaxation times of the two Cl35 resonance lines in methyl chloroform at 77°K.In general, the available proton T1 and linewidth data correlate well with our chlorine results; this agreement is discussed. The chlorin...read more
Citations
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Journal ArticleDOI
Preparation and chlorotropic transformation of crystalline diazaphosphetidine
TL;DR: In this paper, a stable crystalline 1, 3-dimethyltrichloroacetamidinium tetrachiordphosphorate (II) was made by rapid cooling from the liquid, which is unstable under normal conditions.
Journal ArticleDOI
Thermoactivated molecular motions in solids and determination of the energy of their activation by NQR spectroscopy methods
TL;DR: In this article, the activation energy of thermoactivated molecular motions in solids is determined by examining the influence of these motions on the temperature dependence of the nuclear quadrupole spin-lattice relaxation rate and NQR signal intensity for chlorine-35.
Journal ArticleDOI
Molecular dynamics and quadrupole relaxation in solid trimethylamine– and trimethylphosphine–boron trichloride complexes
P Kątowski,Mariusz Maćkowiak +1 more
TL;DR: In this article, the temperature dependence of quadrupole spin-lattice relaxation time of 35 Cl nuclei has been measured in solid trimethylamine and trimethylphosphine-boron trichloride complexes.
Journal ArticleDOI
A simple method for determining the orientation of magnetic axes in large single crystals for nuclear quadrupole resonance observations
TL;DR: In this article, the orientation of the magnetic axes in the single crystal samples, grown in glass tubes, that are commonly used in nuclear quadrupole resonance was determined using a simple and rapid method.
References
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Journal ArticleDOI
Effects of Diffusion on Free Precession in Nuclear Magnetic Resonance Experiments
H. Y. Carr,Edward M. Purcell +1 more
TL;DR: In this paper, the effect of diffusion on free precession in nuclear resonance has been studied, and a new scheme for measuring the transverse relaxation time is described, which largely circumvents the diffusion effect.
Journal ArticleDOI
Relaxation Effects in Nuclear Magnetic Resonance Absorption
TL;DR: In this article, the authors studied the effect of the thermal motion of the magnetic nuclei upon the spin-spin interaction in a rigid lattice and the line width of the absorption line.
Book ChapterDOI
Quadrupole Effects in Nuclear Magnetic Resonance Studies of Solids
Morrel H. Cohen,F. Reif +1 more
TL;DR: The field of electric quadrupole interactions in nuclear magnetic resonance can be divided roughly into two areas according to the relative magnitude of the nuclear quadrupoles interactions as discussed by the authors, which can be classified into two categories according to their relative importance.
Journal ArticleDOI
Structural Investigations by Means of Nuclear Magnetism. II. Hindered Rotation in Solids
H. S. Gutowsky,G. E. Pake +1 more
TL;DR: The experimental absorption line widths, for nuclei with spin 1/2, at nuclear magnetic resonance are given as a function of temperature for a number of molecular crystals.
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