کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1202474 | 965071 | 2011 | 17 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Proline-based chiral stationary phases: A molecular dynamics study of the interfacial structure Proline-based chiral stationary phases: A molecular dynamics study of the interfacial structure](/preview/png/1202474.png)
Proline chains have generated considerable interest as a possible basis for new selectors in chiral chromatography. In this article, we employ molecular dynamics simulations to examine the interfacial structure of two diproline chiral selectors, one with a terminal trimethylacetyl group and one with a terminal t-butyl carbamate group. The solvents consist of a relatively apolar n-hexane/2-propanol and a polar water/methanol mixture. We begin with electronic structure calculations for the two chiral selectors to assess the energetics of conformational changes, particularly along the backbone where the amide bonds can alternate between cis and trans conformations. Force fields have been developed for the two selectors, based on these ab initio calculations. Molecular dynamics simulations of the selective interfaces are performed to examine the preferred backbone conformations, as a function of end-group and solvent. The full chiral surface includes the diproline selectors, trimethylsilyl end-caps, and silanol groups. Connection is made with selectivity measurements on these interfaces, where significant differences [1] are observed between these two very similar selectors.
Journal: Journal of Chromatography A - Volume 1218, Issue 37, 16 September 2011, Pages 6331–6347