Design and synthesis of enantiomerically pure chiral sandwichlike lamellar structure: New explorations from molecular building blocks to three-dimensional morphology

This article reports a pair of novel chiral sandwichlike complexes for the first time. In the two complexes, lanthanide Eu³⁺ ions and Na+ ions are sandwiched between Schiff base ligands, resulting in a two-dimensional plane. For both of the complexes, the intraplane and interplane interactions are utterly different. The adjacent planes are held together by weak van der Waals forces, while the single plane is formed by covalently bonded intraplane N-Eu-O, O-Eu-O, and O-Na-O atoms. On the basis of this characteristic information derived from their molecular building blocks, we studied three-dimensional morphology which has good agreement with expected lamellar morphology. Furthermore, to examine the chiroptical and stable activities, the CD spectra were investigated in the solution of methanol and five different solid forms.