Interfacial Coordination Induced Crystalline Metallacyclic Membrane for High-Performance Enantioseparation

Abstract

Membranes offer an attractive route to efficient enantioseparation, especially compared with energy-intensive techniques like chromatography. However, tuning membrane structure and porosity to separate chiral molecules remains challenging. Here, we present a process for producing intrinsically chiral, ordered discrete metallacycycle 1 membranes on polyacrylonitrile supports through interfacial coordination-driven self-assembly using organic precursor 2 and metallic precursor 3. These chiral membranes, with their orientated architecture, exhibit ultra-high enantioselectivity (up to 100%) and permeation efficiency for racemic 1-phenylethanol, 1-phenylethylamine, and 2-phenylglycinol. Thermodynamic data and molecular simulations revealed the retarded transport mechanism of the membrane, resulting in highly efficient enantioseparation. Notably, when integrated into a circuit-controlled 3D-printed module, the aligned metallacyclic membrane retained its enantioselectivity for high-value pharmaceutical racemic salbutamol. This approach provides a feasible strategy for creating supramolecular metallacyclic channels in chiral membranes, demonstrating the potential for accurate enantioseparations.