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.