Chirality Induction and Amplification in the 2, 2, 2‐Trifluoroethanol⋅⋅⋅Propylene Oxide Adduct1. (4th June 2014)

• Record Type: Journal Article
• Authors: Thomas, Javix; Jäger, Wolfgang; Xu, Yunjie
• Is Part Of: Angewandte Chemie. Volume 126:Number 28(2014)
• Page Start: 7405
• Page End: 7408
• Publication Date: 2014-06-04
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201403838
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Chirality induction and amplification in a model system, that is, the 2, 2, 2‐trifluoroethanol (TFE)⋅⋅⋅propylene oxide (PO) adduct, were investigated using free‐space and cavity‐based Fourier transform microwave spectroscopy, complemented with high level ab initio calculations. Rotational spectra of four out of eight predicted TFE⋅⋅PO adducts were assigned, and the remaining four were shown to relax to the geometries of the four observed in a jet expansion. The <italic>g</italic>+ TFE⋅⋅⋅S‐PO adduct was found to be favored over that of <italic>g</italic>− TFE⋅⋅⋅S‐PO by a factor of 2.8 at 60 K. This difference contrasts the TFE dimer for which an extreme case of chirality synchronization was previously reported. All TFE⋅⋅⋅PO conformers observed take on the open arrangement, in contrast to 2‐fluoroethanol⋅⋅⋅PO, which prefers the closed arrangement. Furthermore, perfluorination at CH₃ increases the hydrogen‐bonding energy by about 70 % over its ethanol counterpart.</p> </abstract>