ChemInform Abstract: A DETERMINATION OF INDIVIDUAL SPECTRAL DENSITIES IN A SMECTIC LIQUID CRYSTAL FROM ANGLE DEPENDENT NUCLEAR SPIN RELAXATION MEASUREMENTS

1984 ◽  
Vol 15 (12) ◽  
Author(s):  
T. M. BARBARA ◽  
R. R. VOLD ◽  
R. L. VOLD



1977 ◽  
Vol 80 (1) ◽  
pp. 235-243 ◽  
Author(s):  
H. J. Hackelöer ◽  
H. Selbach ◽  
O. Kanert ◽  
A. W. Sleeswyk ◽  
G. Hut


1970 ◽  
Vol 48 (6) ◽  
pp. 793-804 ◽  
Author(s):  
Ronald Y. Dong ◽  
Myer Bloom

The proton and fluorine spin relaxation time T1 has been measured in CH4, CF4, CHF3, and CH3F gases at low densities. By measuring the dependence of T1 on density near the characteristic T1 minimum, new information has been obtained on the spin–rotation interaction coupling constants in CF4, CHF3, and CH3F. The CH4 system was used to test the validity of this method since the spin–rotation coupling constants are accurately known for CH4. The correlation function for the spin–rotation interaction was found to be exponential within experimental error for all of the molecules studied. In the analysis of the experimental data, the effects of the dipolar interactions and of nuclear spin symmetry considerations were completely neglected. The validity of these approximations is discussed in the Appendix.





2021 ◽  
Author(s):  
Neil Robinson ◽  
Eric May ◽  
Michael Johns

Understanding solid-fluid interactions within porous materials is critical for their efficient utilisation across chemical reaction and separation processes. However, detailed characterisation of interfacial phenomena within such systems is hampered by their optically opaque nature. Motivated by the need to bridge this capability gap, we detail here the application of low magnetic field 2D <sup>1</sup>H nuclear spin relaxation measurements as a non-invasive probe of sorbate/sorbent interactions, exploring the relaxation characteristics exhibited by liquid adsorbates confined to a model mesoporous silica. For the first time, we demonstrate the capacity of such measurements to distinguish functional group-specific relaxation phenomena across a diverse range of protic adsorbates of wide importance as solvents, reagents, and hydrogen carriers, with distinct relaxation environments assigned to the alkyl and hydroxyl moieties of the confined liquids. Uniquely, this relaxation behaviour is shown to correlate with adsorbate acidity, with the observed relationship rationalised on the basis of surface-adsorbate proton exchange dynamics.





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