Photochemistry of Pivalaldehyde in Solution Studied by CIDNP

1973 ◽  
Vol 51 (18) ◽  
pp. 3032-3038 ◽  
Author(s):  
Holger E. C. Chen ◽  
Arend Groen ◽  
Michael Cocivera
Keyword(s):  
Free Radicals ◽  
Spin Polarization ◽  
Nuclear Spin ◽  
The Other ◽  
Radical Reactions ◽  
Carbonyl Carbon ◽  
Nuclear Spin Polarization ◽  
Butyl Group ◽  
Spin Polarized ◽  
Tertiary Carbon

The n.m.r. spectrum observed during irradiation of pivalaldehyde dissolved in perfluoromethylcyclohexane indicates the formation of several compounds whose hydrogens are spin polarized. These compounds are 2-methylpropane, 2-methylpropene, and pivalaldehyde. A mechanism involving radical reactions which is consistent with these results is presented. According to this mechanism, the primary photochemical step is cleavage of the bond between the carbonyl carbon and the tertiary carbon of the t-butyl group. In contrast, this step does not appear to be important for acetaldehyde. As a test of the proposed mechanism CCl4 is added to trap free radicals. In this case, one of the products is CCl3COH. A mechanism for the formation of this and the other products having nuclear spin polarization is presented.

Tryptophan 13C nuclear-spin polarization generated by intraprotein electron transfer in a LOV2 domain of the blue-light receptor phototropin

2009 ◽  
Vol 37 (2) ◽  
pp. 382-386 ◽  
Author(s):  
Wolfgang Eisenreich ◽  
Markus Fischer ◽  
Werner Römisch-Margl ◽  
Monika Joshi ◽  
Gerald Richter ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Spin Polarization ◽  
Blue Light ◽  
13C Nmr ◽  
Nuclear Spin ◽  
Nuclear Spin Polarization ◽  
Blue Light Receptor ◽  
Spin Polarized ◽  
Light Receptor

13C-NMR experiments were performed on photo-excited fully and partially 13C-labelled LOV2 domains of the blue-light receptor phototropin. In the present paper, we report on nuclear-spin polarized tryptophan resonances that are generated by light-induced intraprotein electron transfer to the FMN cofactor. The spectra are discussed with respect to earlier data obtained from 13C-NMR experiments on unlabelled LOV2 domains that have been reconstituted with FMN 13C isotopologues.

Nuclear spin polarization by out-of-plane spin injection from ferromagnet into an InAs heterostructure

2012 ◽  
Vol 1396 ◽  
Author(s):  
Tomotsugu Ishikura ◽  
Takahiro Hiraki ◽  
Takashi Matsuda ◽  
Joungeob Lee ◽  
Kanji Yoh
Keyword(s):  
Magnetic Field ◽  
Spin Polarization ◽  
Nuclear Spin ◽  
Spin Injection ◽  
Hall Voltage ◽  
Nuclear Spin Polarization ◽  
Polarized Electrons ◽  
Spin Polarized ◽  
Magnetic Metal ◽  
Out Of Plane

AbstractWe have investigated an InAs channel Hall-bar structure with ferromagnetic spin injector in one of the current terminals. After magnetizing the Fe electrode, spin polarized electrons are injected through the edge of the isolation mesa structure and the anomalous Hall voltage is observed, when electrons are injected from the ferromagnetic terminal. However, when electrons are injected from the non-magnetic metal (Ti/Au) of opposite terminal, the Hall voltage disappeared to the variation error level due to the fabrication imperfections. This result suggests the possibility that out-of-plane spin injection from the channel edge lead to perpendicular nuclear magnetic field. It is presumably caused by nuclear spin polarization in InAs channel near the spin source edge through Overhauser effect. The estimated internal magnetic field was 2000 Gauss.

Dynamical Nuclear Polarization

2018 ◽  
Author(s):  
M. M. Glazov
Keyword(s):  
Spin Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Magnetic Moments ◽  
Nonlinear Effects ◽  
Many Body ◽  
Nuclear Spin Polarization ◽  
Optical Resonances ◽  
Dynamical Nuclear Polarization ◽  
Temperature Concept

The transfer of nonequilibrium spin polarization between the electron and nuclear subsystems is studied in detail. Usually, a thermal orientation of nuclei in magnetic field is negligible due to their small magnetic moments, but if electron spins are optically oriented, efficient nuclear spin polarization can occur. The microscopic approach to the dynamical nuclear polarization effect based on the kinetic equation method, along with a phenomenological but very powerful description of dynamical nuclear polarization in terms of the nuclear spin temperature concept is given. In this way, one can account for the interaction between neighbouring nuclei without solving a complex many-body problem. The hyperfine interaction also induces the feedback of polarized nuclei on the electron spin system giving rise to a number of nonlinear effects: bistability of nuclear spin polarization and anomalous Hanle effect, dragging and locking of optical resonances in quantum dots. Theory is illustrated by experimental data on dynamical nuclear polarization.

scholarly journals Dynamics of nuclear spin polarization induced and detected by coherently precessing electron spins in fluorine-doped ZnSe

2016 ◽  
Vol 93 (8) ◽  
Author(s):  
F. Heisterkamp ◽  
E. Kirstein ◽  
A. Greilich ◽  
E. A. Zhukov ◽  
T. Kazimierczuk ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Nuclear Spin ◽  
Electron Spins ◽  
Nuclear Spin Polarization

Magnetic field dependence of fluorine-19 nuclear spin polarization. The system tetrafluorobenzoquinone-tetrafluorohydroquinone

1982 ◽  
Vol 104 (22) ◽  
pp. 5878-5883 ◽  
Author(s):  
Richard S. Hutton ◽  
Heinz D. Roth ◽  
Marcia L. Manion Schilling ◽  
Anthony M. Trozzolo ◽  
Thomas M. Leslie
Keyword(s):  
Magnetic Field ◽  
Spin Polarization ◽  
Field Dependence ◽  
Nuclear Spin ◽  
Magnetic Field Dependence ◽  
Nuclear Spin Polarization

Effective collinear optical pumping for nuclear spin polarization

2014 ◽  
Vol 31 (10) ◽  
pp. 2278 ◽  
Author(s):  
Sung Jong Park ◽  
Taeksu Shin ◽  
Ju Hahn Lee ◽  
Gi Dong Kim ◽  
Yong Kyun Kim
Keyword(s):  
Spin Polarization ◽  
Nuclear Spin ◽  
Optical Pumping ◽  
Nuclear Spin Polarization
Sign in / Sign up

Export Citation Format

Share Document