Temperature dependence of proton spin-lattice relaxation times in some paramagnetic transition metal acetylacetonate complexes. The possible influence of the Jahn-Teller effect on electron spin relaxation

1977 ◽  
Vol 99 (4) ◽  
pp. 1281-1282 ◽  
Author(s):  
David M. Doddrell ◽  
M. Robin Bendall ◽  
David T. Pegg ◽  
Peter C. Healy ◽  
Anthony K. Gregson
Keyword(s):  
Spin Relaxation ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Electron Spin Relaxation ◽  
Spin Lattice ◽  
Metal Acetylacetonate ◽  
Jahn Teller ◽  
Jahn Teller Effect

Relaxationszeiten des Elektronenspins von Radikalen in einigen bestrahlten Aminosäuren bei 4,2 °K

1966 ◽  
Vol 21 (3) ◽  
pp. 296-300 ◽  
Author(s):  
G. Bürk ◽  
G. Schoffa
Keyword(s):  
Amino Acids ◽  
Spin Relaxation ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Electron Spin Relaxation ◽  
Spin Lattice ◽  
Saturation Method ◽  
Rapid Adjustment ◽  
Inhomogeneous Line Broadening

Electron spin relaxation times of the irradiated amino acids acetyl valine, sarcosine, betaine, and glycine have been measured at 4.2 °K with two different methods. From the exponential decrease of signals due to saturation after rapid adjustment of the ESR spectrometer on resonance, the following spin-lattice relaxation times have been measured: acetyl valine T1= 0.2 sec, sarcosine T1=0.14 sec, betaine T1=0.07 sec, glycine T1 ∼ 0.3 sec. By the PORTIS saturation method the product T1 T2 was measured, and, T1 being known, the following spin-spin relaxation times T2 have been obtained: acetyl valine 2.1.10-9sec, sarcosine 1.10-9sec, betaine 9.10-10sec. All measured amino acids show the saturation behaviour of substances with “inhomogeneous” line broadening.

Electron Spin Relaxation of (Diphenyl) in Dimethoxyethane

1975 ◽  
Vol 30 (6-7) ◽  
pp. 883-890 ◽  
Author(s):  
F. Köksal ◽  
G. J. Krüger
Keyword(s):  
Spin Relaxation ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Dipolar Interaction ◽  
Translational Diffusion ◽  
Spin Lattice Relaxation ◽  
High Concentration ◽  
Electron Spin Relaxation ◽  
Spin Lattice ◽  
Electron Relaxation

Abstract The electron relaxation times T1 and T2 have been measured by ESR pulse techniques in solutions of normal and perdeuterated (diphenyl)- in dimethoxyethane at various radical concentrations and temperatures. The results are discussed in terms of different relaxation mechanisms. The most important contribution to spin-lattice relaxation at high concentration is dipolar interaction with other radical electrons modulated by translational diffusion. Spin-spin relaxation has in addition contributions from electron exchange and ion pairing.

PROTON SPIN-LATTICE RELAXATION TIMES OF HUMIC ACIDS AS DETERMINED BY SOLUTION NMR

Soil Science ◽  
2003 ◽  
Vol 168 (2) ◽  
pp. 128-136 ◽  
Author(s):  
Kaijun Wang ◽  
L. Charles Dickinson ◽  
Elham A. Ghabbour ◽  
Geoffrey Davies ◽  
Baoshan Xing
Keyword(s):  
Humic Acids ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Solution Nmr ◽  
Spin Lattice

Histopathological Evidence in Support of the Association of Elevated Proton Spin-lattice Relaxation Times with the Malignant State

1979 ◽  
Vol 65 (2) ◽  
pp. 157-162 ◽  
Author(s):  
S. S. Ranade ◽  
Smita Shah ◽  
G. V. Talwalkar
Keyword(s):  
Human Cancer ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Malignant Cell ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Histopathological Study ◽  
Spin Lattice ◽  
Malignant State ◽  
T Values

The pulsed nuclear magnetic resonance technique was explored for its potential diagnostic value in human cancer. Measurements of proton spin-lattice relaxation times (T1) of cellular water protons of normal and malignant esophageal tissues showed elevated T, values in the latter. In some cases, tissues which appeared normal on gross examination assumed as uninvolved tissues had T, values higher than the other grossly uninvolved tissues and often closer to the T, of the corresponding tumor tissue. A histopathological study of the assumed uninvolved areas also studied for the T, values was therefore undertaken. A preliminary study demonstrated the presence of malignant cell groups or clusters in some of the uninvolved samples with higher T1 compared to the true uninvolved tissues, which had a normal histological picture and low T, values. This observation has brought out the importance of histopathological studies in addition to relaxation studies to comprehend contributory factors to relaxation. Secondly, it lends support to the thesis of elevated T, values being characteristics of the malignant state.

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