Elimination of Hl inhomogeneity and spin-spin relaxation in the determination of spin-lattice relaxation times

1970 ◽  
Vol 2 (2) ◽  
pp. 174-180 ◽  
Author(s):  
K Van Putts
Keyword(s):  
Spin Relaxation ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice

A Selective Determination of the Proton Nuclear Relaxation Times of the Alkaloid Vindoline

1972 ◽  
Vol 50 (4) ◽  
pp. 497-503 ◽  
Author(s):  
R. Burton ◽  
C. W. M. Grant ◽  
L. D. Hall
Keyword(s):  
Relaxation Time ◽  
Spin Relaxation ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Nuclear Relaxation ◽  
Methyl Group ◽  
Selective Determination ◽  
Spin Lattice

An audiofrequency-pulse n.m.r. spectrometer has been used to measure the nuclear relaxation times of individual protons of the alkaloid, vindoline. For this substance in deuterochloroform solution the spin–lattice relaxation times (T1) vary between 1.15 and 1.50 s and the spin–spin relaxation times (T2) are between 0.90 and 1.40 s. The N-methyl group has the shortest relaxation time of those resonances which were measured. A discussion of the apparatus and methodology is given.

A Selective Determination of the Proton Nuclear Relaxation Times of the Alkaloid Vindoline: An Extension via Fourier Transform Measurements

1974 ◽  
Vol 52 (5) ◽  
pp. 829-832 ◽  
Author(s):  
L. D. Hall ◽  
Caroline M. Preston
Keyword(s):  
Fourier Transform ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Nuclear Relaxation ◽  
Transform Method ◽  
Fourier Transform Method ◽  
Selective Determination ◽  
Spin Lattice

A Fourier Transform method has been used to measure the spin–lattice relaxation times of essentially all the protons of the alkaloid, vindoline. It is shown that even for a molecule of this size substantial and potentially useful differences exist in the experimental relaxation times which reflect the degree of crowding of each proton by other protons.

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.

The determination of zero-field splittings from measurements of spin-lattice relaxation times

1974 ◽  
Vol 35 (5) ◽  
pp. 73-76 ◽  
Author(s):  
A.M. Vasson ◽  
A. Vasson ◽  
A. Gavaix ◽  
T.S. Yalcin ◽  
P. Steggles ◽  
...  
Keyword(s):  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Zero Field ◽  
Spin Lattice

Self-Diffusion in the Ionic Plastic Phase of (CH3 )3 NHClO4 Studied by 1H NMR and Electrical Conductivity

1996 ◽  
Vol 51 (1-2) ◽  
pp. 83-86
Author(s):  
Hiroyuki Ishida ◽  
Yoshihiro Furukawa
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Spin Relaxation ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Self Diffusion ◽  
Spin Lattice ◽  
H Nmr ◽  
Plastic Phase

Abstract Spin-lattice relaxation times (T1) and spin-spin relaxation times (T2) of 1H NMR and the electrical conductivity (σ) of trimethylammonium perchlorate were measured in the ionic plastic phase obtainable above 480 K. In this phase, both the cation and anion were revealed to perform self-diffusion. The activation energy (Ea ) of the cationic diffusion was evaluated to be 55 ± 4 and 50 ± 4 kJ mol-1 from 1H T1 and 1H T2 respectively, while Ea of the anionic diffusion was 64 ±3 kJ mol-1 from the electrical conductivity.

Sign in / Sign up

Export Citation Format

Share Document