Tuning organic crystal chirality by the molar masses of tailored polymeric additives

Xichong Ye,Xinhua Wan,Jie Zhang,Zhaoxu Wang,Bowen Li,Jing Li

doi:10.1038/s41467-021-27236-1

Xichong Ye, Xinhua Wan + Show 4 more

Open Access

https://doi.org/10.1038/s41467-021-27236-1

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Abstract

Hierarchically ordered chiral crystals have attracted intense research efforts for their huge potential in optical devices, asymmetric catalysis and pharmaceutical crystal engineering. Major barriers to the application have been the use of costly enantiomerically pure building blocks and the difficulty in precise control of chirality transfer from molecular to macroscopic level. Herein, we describe a strategy that offers not only the preferred formation of one enantiomorph from racemic solution but also the subsequent enantiomer-specific oriented attachment of this enantiomorph by balancing stereoselective and non-stereoselective interactions. It is demonstrated by on-demand switching the sign of fan-shaped crystal aggregates and the configuration of their components only by changing the molar mass of tailored polymeric additives. Owing to the simplicity and wide scope of application, this methodology opens an immediate opportunity for facile and efficient fabrication of one-handed macroscopic aggregates of homochiral organic crystals from racemic starting materials.

Highlights

Ordered chiral crystals have attracted intense research efforts for their huge potential in optical devices, asymmetric catalysis and pharmaceutical crystal engineering
Stabilized crystalline building blocks with high shape anisotropy are essential to this process[31,32], which can be achieved by using additives[29,33] or particular ripening conditions[5,24]
We posit that macroscopic homochiral crystal aggregates of a single enantiomer could be generated from a racemic solution by virtue of synergistic combination of stereoselective and nonstereoselective interactions

Summary

Introduction

Ordered chiral crystals have attracted intense research efforts for their huge potential in optical devices, asymmetric catalysis and pharmaceutical crystal engineering. When a L-polymer with a medium molar mass is used, Plus (P)-type fan-shaped crystal aggregates of D-phydroxyphenylglycine p-toluenesulfonate (D-pHpgpTs) are obtained (Fig. 2a). Changing the molar mass of the polymer can switch the chirality of the hierarchically ordered structures formed on both molecular and supramolecular levels (Supplementary Fig. 1).

Results

Conclusion