English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

The configuration and the dynamics of the -CD3 groups in methyl deuterated dimethylmalonic acid. A single crystal deuteron NMR study

MPS-Authors
/persons/resource/persons93258

Haeberlen,  Ulrich
Research Group Prof. Dr. Haeberlen, Max Planck Institute for Medical Research, Max Planck Society;

/persons/resource/persons128263

Zimmermann,  Herbert
Department of Molecular Physics, Max Planck Institute for Medical Research, Max Planck Society;
Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Max Planck Society;
Zimmermann Group, Max Planck Institute for Medical Research, Max Planck Society;
Emeritus Group Biophysics, Max Planck Institute for Medical Research, Max Planck Society;

Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Idziak, S., Haeberlen, U., & Zimmermann, H. (1991). The configuration and the dynamics of the -CD3 groups in methyl deuterated dimethylmalonic acid. A single crystal deuteron NMR study. Molecular Physics, 73(3), 571-586. doi:10.1080/00268979100101391.


Cite as: https://hdl.handle.net/11858/00-001M-0000-0019-ACC5-3
Abstract
The angular variation of the deuteron NMR of single crystals of methyl deuterated dimethylmalonic acid, C(CD3)2(COOH)2 (DMMA), was measured at room temperature and at 56 K. From the room temperature data the motionally averaged deuteron quadrupole coupling tensors for rapidly reorienting methyl groups are determined. The C-Cmethyl bond directions are inferred from the unique principal axes of these tensors. A semi-quantitative analysis of the 56 K data leads to the conclusion that at this temperature the methyl groups are immobile and that the configuration of the two methyl groups within the DMMA molecule is an eclipsed one. By line shape analysis of deuteron spectra recorded for 290 K > T > 60 K the Arrhenius parameters for reorienting -CD3 groups E a = 9·5 kJ mol-1 and k (D) 0 = 0·8 × 1011 s-1 were determined. No features giving evidence for tunnelling could be observed in the low temperature deuteron spectra. An upper limit of 3 kHz is derived for the -CD3 tunnel frequency v (D) t for T → 0.