Latent one-dimensional luminescent coordination polymer emerging from copper(i) iodide secondary building units

Abstract

Luminescent coordination polymers (CPs) often exhibit poor processability and recyclability owing to their insoluble infinite networks. Herein, we report a reversible vapor-induced structural interconversion between a zero-dimensional (0D) complex and a one-dimensional (1D) luminescent CP, which enables both solution processing and recycling. The 1D CP [Cu₂I₂(AsPh₃)₂(meprz)]_n (Crys-B) with intense yellow emission was converted to the weakly emissive 0D complex Cu₂I₂(AsPh₃)₂(meprz)₂ (Crys-A) upon exposure to 2-methylpyrazine (meprz) vapor, and reverted back to Crys-B upon exposure to acetonitrile (CH₃CN) vapor. This transformation proceeded smoothly without amorphization, allowing film fabrication via casting or spin-coating in the 0D state, followed by vapor-induced polymerization, while enabling recovery via depolymerization. Comparative studies revealed that the arsine ligand (AsPh₃) accelerates vapor-induced switching and enhances the emission contrast relative to its phosphine analog (PPh₃). This study established the first copper(I) halide-based luminescent CP to achieve reversible 0D/1D conversion, offering a practical route for processable and recyclable luminescent materials.