Metal node exchange-driven ligand-strain modulation strategy for one-dimensional crystalline coordination polymers†

Engineering ideal functional coordination polymers (CPs) via post-synthetic modification has emerged as a powerful synthetic strategy to achieve desirable functionalities and superior properties. In this work, we report a versatile ligand-strain modulation strategy that harnesses ligand strain to modify the skeleton conformation of CPs by metal node exchange. A one-dimensional (1D) crystalline CP, Ag(I)-L, featuring a curved ligand geometry, is prepared through a direct synthesis route. Exploiting polarization differences between different metal ions, we successfully regulate the ligand strain, enabling a metal node exchange process that yields another crystalline CP, Cu(I)-L, exhibiting a distinct linear parallel ligand orientation. Significantly, the complete exchange of AgNO₃ to CuI is achieved via solid–liquid contact, while only partial exchange occurs under grinding. This ligand-strain engineering strategy will open new avenues in constructing functional systems and supramolecular materials through dynamic metal exchange and ligand-strain control.