Solid-state NMR characterization of diastereoisomeric chiral stationary phases and their soluble models.

TitleSolid-state NMR characterization of diastereoisomeric chiral stationary phases and their soluble models.
Publication TypeJournal Article
Year of Publication2005
AuthorsBorsacchi, S, Geppi, M, Iuliano, A, Veracini, CA
JournalSolid state nuclear magnetic resonance
Volume28
Pagination193–203
Date Publishedsep
Abstract

Two diastereoisomeric chiral stationary phases (CSPs), devised for enantioselective HPLC, showing unexplained differences in their chromatographic performances, have been characterized, together with their soluble models, by means of 13C-cross polarization/magic angle spinning (CP/MAS), 1H-MAS and 1H-free induction decay (FID) analysis. The NMR investigation of the soluble models has not highlighted significant structural/conformational differences between the two diastereoisomers, but has constituted a useful support for the analysis of the more complex NMR data of the CSPs. The organic chiral selectors of the stationary phases show a poor internal mobility and no conformational differences between the two diastereoisomers have been observed. On the contrary, interesting differences between the two CSPs have been found involving the silanols on the silica surface and the dynamics of the linking chains between the organic selectors and the silica surface itself. An explanation of the chromatographic behaviour has been proposed in terms of different proximity of the organic moieties with respect to the inorganic surface in the two CSPs.

URLhttp://www.scopus.com/inward/record.url?eid=2-s2.0-29144510027&partnerID=40&md5=4e70062793f0df2e9e127a7924845d04 http://www.ncbi.nlm.nih.gov/pubmed/16202569
DOI10.1016/j.ssnmr.2005.08.009