Unraveling the Substituent-Controlled Fluorescence Modulation in One-Dimensional Cd-Based Coordination Polymers: A Structure-Property Relationship Study

The substituent engineering strategy has emerged as a powerful tool for precise modulation of the structure-property relationships in coordination polymers (CPs), yet the rational design of isostructural CPs with tunable dual-channel fluorescence and integrated stimulus-responsive behaviors remains a compelling challenge. Herein, three isostructural, one-dimensional Cd-based CPs (1-3) were rationally designed and hydrothermally synthesized via systematic substituent modification. Notably, the solid-state fluorescence of 1-3 is precisely regulated by the electronic and steric effects of substituents, enabling dual-channel emission encompassing ligand-centered monomer fluorescence and excimer-derived fluorescence. Furthermore, systematic investigations reveal that these CPs exhibit distinct thermoresponsive and mechanoresponsive fluorescence behaviors, which are closely correlated with substituent-induced structural subtlety. This work not only demonstrates the efficacy of substituent engineering in tailoring dual-channel fluorescence within isostructural CPs but also provides insights into the design of multifunctional, stimulus-responsive fluorescent materials for potential applications in sensors and optoelectronics.