Combination of solid-state NMR, molecular mechanics and DFT calculations for the molecular structure determination of methyl glycoside benzoates

AbstractA reliable method for molecular structure determination, excluding single-crystal X-ray diffraction (SCXRD), has been applied to six methyl glycoside tetrabenzoates. The proposed method is based on a global conformational search using molecular mechanics and subsequent DFT calculations guided by a solid-state NMR experiment. The accuracy of the applied method has been verified on three methyl glycoside benzoates for which the SCXRD analysis has been completed. It appeared that the calculated conformations of unprivileged energy could be found in the solid state. Bulky substituents (benzoates) exerted less energetically favored interactions in crystals in contrast to isolated molecules. Therefore, solid-state NMR was revealed to be an indispensable approach for choosing credible conformations from the calculated conformations.

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Exploiting the Synergy of Powder X-ray Diffraction and Solid-State NMR Spectroscopy in Structure Determination of Organic Molecular Solids

The Journal of Physical Chemistry C ◽

10.1021/jp4041106 ◽

2013 ◽

Vol 117 (23) ◽

pp. 12258-12265 ◽

Cited By ~ 64

Author(s):

Dmytro V. Dudenko ◽

P. Andrew Williams ◽

Colan E. Hughes ◽

Oleg N. Antzutkin ◽

Sitaram P. Velaga ◽

...

Keyword(s):

Solid State ◽

Nmr Spectroscopy ◽

Structure Determination ◽

Solid State Nmr ◽

Molecular Solids ◽

X Ray Diffraction ◽

X Ray ◽

Solid State Nmr Spectroscopy

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Structure Determination of Molecular Solids from Powder X-ray Diffraction Data

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314084423 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C1557-C1557

Author(s):

Kenneth Harris

Keyword(s):

Solid State ◽

Structure Determination ◽

Solid State Nmr ◽

Structural Information ◽

Powder Xrd ◽

Computational Techniques ◽

Molecular Solids ◽

X Ray Diffraction ◽

X Ray

Structure determination of organic molecular solids from powder X-ray diffraction (XRD) data [1] is nowadays carried out extensively by researchers in both academia and industry, and the development of new methodology in this field has made particularly significant impact in the pharmaceuticals industry within the last 20 years or so. However, although software for carrying out each stage of the procedure for structure determination from powder XRD data is now readily accessible and relatively straightforward to use, it is essential that the results from such structure determination calculations are subjected to careful scrutiny to confirm that the final structure obtained is actually correct. In this regard, it can be particularly advantageous to augment the analysis of the powder XRD data and to assist the scrutiny of the structural results by considering complementary structural information derived from other experimental and computational techniques. Techniques that can be particularly valuable in this regard include solid-state NMR spectroscopy, energy calculations (either on individual molecules or periodic crystal structures), vibrational spectroscopies, and techniques of thermal analysis (e.g. DSC and TGA). The lecture will give an overview of the current "state of the art" in the structure determination of organic materials from powder XRD data, giving emphasis [2,3] to the opportunities to enhance the structure determination process by making use of information derived from other experimental (especially solid-state NMR) and computational techniques. Recent results will be presented, with emphasis on raising issues of relevance to research on pharmaceutical materials.

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