Carbon-13 NMR studies of chemical-shielding tensors and molecular motion in Meldrum's acid in the solid state

1986 ◽  
Vol 108 (22) ◽  
pp. 6852-6857 ◽  
Author(s):  
K. Takegoshi ◽  
C. A. McDowell
Keyword(s):  
Solid State ◽  
Molecular Motion ◽  
Meldrum's Acid ◽  
Chemical Shielding ◽  
Meldrum’S Acid ◽  
Nmr Studies ◽  
Shielding Tensors

Solid State Carbon-13 NMR Studies of Vulcanized Elastomers. II, Sulfur Vulcanization of Natural Rubber

1987 ◽  
Vol 60 (2) ◽  
pp. 252-277 ◽  
Author(s):  
A. M. Zaper ◽  
J. L. Koenig
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Molecular Motion ◽  
Main Chain ◽  
Repeat Unit ◽  
Crosslinking Agent ◽  
Nmr Studies ◽  
Structural Modifications ◽  
Chain Isomerization ◽  
Cyclic Sulfide

Abstract In summary, the solid-state C-13 NMR technique has proven to be a significant method for the detection of crosslinks and other structural modifications in sulfur-vulcanized NR systems. The use of sulfur as a crosslinking agent by itself generates a considerable amount of main-chain structural modifications. Cyclic sulfide structures and cis-to-trans chain isomerization are detected in addition to polysulfidic crosslinks which are found attached to different carbons of the NR repeat unit. The phenomenon of reversion has also been detected in this study. The nature of the spectral broadening in the NMR spectra of the highly cured vulcanizates has two origins. The broadening arises from lack of molecular motion in the system and from an increase in chemical shift dispersion due to the new structures formed with crosslinking.

Benchmarks for the 13C NMR chemical shielding tensors in peptides in the solid state

2012 ◽  
Vol 527 ◽  
pp. 31-35 ◽  
Author(s):  
Jiří Czernek ◽  
Tomasz Pawlak ◽  
Marek J. Potrzebowski
Keyword(s):  
Solid State ◽  
13C Nmr ◽  
Chemical Shielding ◽  
Shielding Tensors

Solid-state NMR studies of the molecular motion in the kaolinite: DMSO intercalate

1992 ◽  
Vol 114 (17) ◽  
pp. 6867-6874 ◽  
Author(s):  
Melinda J. Duer ◽  
Joao Rocha ◽  
Jacek Klinowski
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Molecular Motion ◽  
Nmr Studies
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