Dynamics of the13C spin‐exchange process in solids: A theoretical and experimental study

1986 ◽  
Vol 85 (12) ◽  
pp. 7077-7086 ◽  
Author(s):  
P. Mark Henrichs ◽  
M. Linder ◽  
J. Michael Hewitt
Keyword(s):  
Experimental Study ◽  
Spin Exchange ◽  
Exchange Process

Direct observation of low spin – high spin electronic ground states and cross-over exchange in manganocene derivatives, (η5-C5H4R)2Mn, R = H, CH3, C2H5 by paramagnetic nuclear magnetic resonance

1986 ◽  
Vol 64 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Daniel Cozak ◽  
François Gauvin ◽  
Jacques Demers
Keyword(s):  
Nmr Spectra ◽  
Spin Exchange ◽  
Exchange Process ◽  
Paramagnetic Species ◽  
Temperature Range ◽  
H Nmr ◽  
Low Field ◽  
Spin Electronic ◽  
Electronic Ground ◽  
C Nmr

The paramagnetic 1H nmr spectra for manganocene (1) and 1.1′-dimethylmanganocene (2), and the 13C nmr spectra for 1,1′-diethylmanganocene (3) have been recorded in toluene solvent over a −90 to 90 °C temperature range. 1 shows a low field and a high field ring proton resonance in its spectrum near −59 °C. At higher temperatures the low field resonance is prevalent and becomes gradually averaged due to a fast spin exchange process that dominates the spectrum at 90 °C. For the ring substituted derivatives 2 and 3, resonances due to only one paramagnetic species were detected in the low temperature range. Above ambient temperature a new spectrum due to rapid spin exchange averaging is observed for these complexes. Results are readily interpreted in terms of ground state molecular cross-over exchanges between the 2E2g, 6A1g, and 2A1g spin states of the complexes.

scholarly journals The xenon hyperpolarization by alexandrite laser spin exchange optical pumping

2019 ◽  
Vol 220 ◽  
pp. 03026 ◽  
Author(s):  
Alexey Putilov ◽  
Alexandr Antipov ◽  
Alexandr Shepelev
Keyword(s):  
Optical Pumping ◽  
Noble Gases ◽  
Spin Exchange ◽  
Noble Gas ◽  
Exchange Process ◽  
Laser Cavity ◽  
Alexandrite Laser ◽  
Optical Elements ◽  
Spin Exchange Optical Pumping ◽  
Magnetic Resonance Imaging Contrast

This paper shows the possibility of the use of a solid-state alexandrite laser as a radiation source for the method of spin-exchange optical pumping of noble gases (xenon, krypton). The use of dispersive optical elements in the laser cavity will allows the adjusting of the radiation wavelength exactly in the rubidium spectral absorption lines 794.7 nm and 780 nm. To obtain a hyperpolarized state of noble gases, it is necessary to excite rubidium atoms for further spin-exchange process with the noble gas nuclei. This fact will allow the increasing of the magnetic resonance imaging contrast in the field of diagnosis of respiratory organs diseases.

scholarly journals Experimental study of spin-exchange effects in elastic and ionizing collisions of polarized electrons with polarized hydrogen atoms

1985 ◽  
Vol 31 (5) ◽  
pp. 2854-2884 ◽  
Author(s):  
G. D. Fletcher ◽  
M. J. Alguard ◽  
T. J. Gay ◽  
V. W. Hughes ◽  
P. F. Wainwright ◽  
...  
Keyword(s):  
Experimental Study ◽  
Spin Exchange ◽  
Hydrogen Atoms ◽  
Polarized Electrons ◽  
Exchange Effects
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