scholarly journals Temperature dependence of X-ray absorption and nuclear magnetic resonance spectra: probing quantum vibrations of light elements in oxides

2017 ◽  
Vol 19 (8) ◽  
pp. 6246-6256 ◽  
Author(s):  
Ruidy Nemausat ◽  
Christel Gervais ◽  
Christian Brouder ◽  
Nicolas Trcera ◽  
Amélie Bordage ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Temperature Dependence ◽  
Light Element ◽  
Thermal Fluctuations ◽  
Light Elements ◽  
X Ray ◽  
Nuclear Magnetic Resonance Spectra ◽  
X Ray Absorption ◽  
Quantum Vibrations

Probing the quantum thermal fluctuations of nuclei in light-element oxides using XANES and NMR spectroscopies.

Structure and nuclear magnetic resonance spectra of 6-bromo-3,3′,4′,5,7-penta-O-methylcatechin

1985 ◽  
Vol 63 (8) ◽  
pp. 2176-2180 ◽  
Author(s):  
F. W. B. Einstein ◽  
E. Kiehlmann ◽  
E. K. Wolowidnyk
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Title Compound ◽  
Bromine Atom ◽  
Heterocyclic Ring ◽  
Equatorial Orientation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Nuclear Magnetic Resonance Spectra ◽  
Ring Conformations

The title compound has been synthesized by selective debromination of 6,8-dibromocatechin and indirect methylation of the resulting 6-bromocatechin via its pentaacetate. The structure of C20H23BrO6 has been determined by X-ray crystallography. The compound crystallizes in the space group P1 with a = 9.589(3) Å, b = 11.576(3) Å, c = 11.326(3) Å, α = 118.80(3)°, β = 93.23(3)°, γ = 111.44(3)°, ρc = 1.481 g cm−3, and Z = 2. Intensities were measured for 2584 independent reflections (2θ < 45°) of which 2213 were observed (I > 3.0σ(I)) and used in subsequent refinement (final R values were R = 0.0268 and Rw = 0.0344). Crystallographic and pmr data confirm the position of the bromine atom at C-6, the trans-diaxial arrangement of H-2/H-3 and the quasi-equatorial orientation of the 3,4-dimethoxyphenyl group (ring B). The two heterocyclic ring conformations are consistent with the expected flexibility of the molecule.

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