Eiji Yashima
Nagoya University, Japan
Title: Reversible switching and memory of macromolecular helicity of a polyacetylene in the solid state and application to switchable enantio-separation in HPLC
Biography
Biography: Eiji Yashima
Abstract
The helix is ubiquitous in nature and one of the prevalent structural motifs for biological polymers, playing key roles in their sophisticated functions, such as chiral recognition, enantio-selective catalysis, and replication. Here, a quite unique helical polyacetylene is shown, whose main-chain helicity and axial chirality of the pendants are induced in the solid state accompanied by significant amplification of the chirality in a sequential or synchronized fashion upon interaction with a nonracemic alcohol. The induced macromolecular helicity and axial chirality are automatically memorized and further switched in the solid state. This unprecedented feature enables in this polymer the switchable chiral stationary phase (CSP) for separating enantiomers by high-performance liquid chromatography (HPLC) whose elution order or enantio-selectivity can be reversibly switched in the column for the first time. Separation of enantiomers by HPLC is now an essential technique for the research and development of chiral drugs in the pharmaceutical industry and a number of CSPs have been commercialized. However, none of them can switch the elution order of enantiomers, which is one of the most important issues to resolve.