Complexity and Optical Activity Regulation Through Chirality Engineering in Ag-Thiolate Coordination Polymers

Extending morphological complexity and thus achieving emergent functions remain a central challenge in materials science. Here, we report a chirality-engineering strategy to tune morphological complexity and optical activity (OA) in Ag-thiolate coordination polymers (ATCPs). By introducing either the opposite enantiomer D-cys or the achiral 3-mercaptopropionic acid (MPA) into L-cys-induced ATCP synthesis, we found two coinduction systems exhibiting distinct molecular mixing behaviors quantified via the entropy of mixing (EoM) of thiol precursors. The resulting morphologies, including triangular nanosheets, flower-like architectures, nanoscrolls, and nanotube-like assemblies, were quantitatively analyzed using a graph-theoretical complexity index (CI). In the L-/D-cys system, increasing EoM led to chirality cancelation, a decreased CI and an attenuated g-factor, demonstrating that maximum EoM does not necessarily generate higher complexity or stronger OA. In contrast, in the L-cys/MPA system, packing mismatch transformed maximum EoM into an enhanced CI alongside OA inversion and enhancement (a maximal 8.3-fold enhancement). These results reveal that the molecular role of the second thiol component, rather than EoM alone, determines whether molecular mixing suppresses or amplifies complexity and OAs. This work provides ligand-modification strategy for programming complex functional coordination-polymer assemblies.