scholarly journals Quantum revivals and magnetization tunneling in effective spin systems

2016 ◽  
Vol 18 (3) ◽  
pp. 033029 ◽  
Author(s):  
M Krizanac ◽  
D Altwein ◽  
E Y Vedmedenko ◽  
R Wiesendanger
2007 ◽  
Vol 99 (16) ◽  
Author(s):  
Michael J. Hartmann ◽  
Fernando G. S. L. Brandão ◽  
Martin B. Plenio
Keyword(s):  

1996 ◽  
Vol 89 (5) ◽  
pp. 1397-1408 ◽  
Author(s):  
LAWRENCE LOHR

1975 ◽  
Vol 116 (7) ◽  
pp. 485 ◽  
Author(s):  
V.G. Pokazan'ev ◽  
G.V. Skrotskii ◽  
L.I. Yakub

1993 ◽  
Vol 58 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Václav Křeček ◽  
Miloš Buděšínský ◽  
Bohumil Máca

Reaction of 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) and 20β,28-epoxy-21,22-dioxo-19α,19βH-ursan-3β-yl acetate (IIIb) with diazomethane afforded derivatives XII-XIV with spiroepoxide group in position 21 or 22, which were further converted into hydroxy derivatives XV and XVII. Ethylene ketals VIII-X were also prepared. In connection with the determination of position and configuration of the functional groups at C(21) and C(22), the 1H and 13C NMR spectral data of the prepared compounds are discussed. Complete analysis of two four-spin systems in the 1H NMR spectrum of bisethylenedioxy derivative Xb led to the proton-proton coupling constants from which the structure with two 1,4-dioxane rings condensed with ring E, and their conformation, was derived.


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