Designed Syntheses of Chiral Iodo/Thiocyano Cuprous 3D Supramolecular Frameworks with Ferroelectricity and Circular Polarization Luminescence

A pair of chiral organophosphorus iodide ligands, R/S-2’-(diphenylphosphaneyl)-[1,1’-binaphthalen]-2-yl)(methyl)diphenylphosphonium iodide (abbreviated as R/S-MBINAP⁺I⁻), was designedly synthesized to react with CuSCN, forming a pair of chiral iodo/thiocyano cuprous three-dimensional (3D) supramolecular frameworks, R/S-[Cu₂(SCN)₂I(MBINAP)]_n (abbreviated as R/S-1). The 3D architectures were constructed by the connection of [Cu₂(SCN)₂]_n chains with I⁻ and R/S-MBINAP⁺ ligands hanging on each side by coordination, through strong C–H···π interactions among the neighbouring chains, showing excellent thermal stability. R/S-1 displayed characteristic chiral property of circular dichroism with mirror-symmetric cotton effect. Moreover, R-1 exhibited fasinating ferroelectricity with P_r of 0.036 µC·cm^− 2, E_c of 8.2 kV·cm^− 1 and P_s of 0.13 µC·cm^− 2. As expected, R/S-1 showed luminescence with relatively long lifetime of 569 us (R-1) and 568 us (S-1). Furthermore, R/S-1 exhibited good circular polarization luminescence (CPL) with g_lum being ± 3.0 × 10^− 3. Theoretical calculations have been carried out to clarify the band structure of R-1. This work provides a new research strategy for the design and syntheses of chiral halogeno/pseudohalogeno cuprous polymers, and opens up a prospect for the multiple applications of chiral iodo/thiocyano cuprous materials.