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Title: Cross polarization and magic angle sample spinning NMR spectra of model organic compounds. 1. Highly protonated molecules

Journal Article · · J. Am. Chem. Soc.; (United States)
DOI:https://doi.org/10.1021/ja00346a006· OSTI ID:5833414

CP/MAS /sup 13/C NMR spectra were obtained at various contact times on ten solid organic compounds containing a variety of simple functional groups. The spectra show that signal intensities that agree with atomic ratios can be obtained with a contact time of 2.25 ms and often with a contact time as short as about 1 ms. Computer analysis of signal intensities obtained at a minimum of ten different contact times provides T/sub CH/ data that are consistent with these experimental results. The experimental results are also consistent with the previously reported lack of significant variation in the spectra of complex organic solids obtained with contact times of about 1 to 3 ms. In general, nonprotonated carbon atoms polarize more slowly than protonated carbon atoms. The compounds exhibit a wide range of proton spin lattice relaxation times. Some compounds exhibit more resonances than are found in the /sup 13/C(/sup 1/H) spectra of the compounds in solution because the crystalline environment removes the nominal spatial equivalence found for carbon atoms related to each other by unimolecular symmetry elements.

Research Organization:
Univ. of Utah, Salt Lake City
DOE Contract Number:
AC02-78ER05006
OSTI ID:
5833414
Journal Information:
J. Am. Chem. Soc.; (United States), Vol. 105:8
Country of Publication:
United States
Language:
English