Kaya, İsmetKolcu, FeyzaYılmaz, Zumre NurYağmur, Hatice Karaer2026-02-032026-02-0320251226-086Xhttps://doi.org/10.1016/j.jiec.2025.11.026https://hdl.handle.net/20.500.12428/34296In this study, a series of naphthalene-tethered Schiff bases and their corresponding poly(phenoxy-imine) derivatives were synthesized through condensation and oxidative polycondensation reactions. Quantitative comparison revealed that only SB2 exhibited a remarkable 28-fold enhancement in fluorescence intensity upon coordination with Sn2+ ions, ascribed to by a chelation-enhanced fluorescence (CHEF) mechanism accompanied by the suppression of ?C=N- isomerization. The chemosensor exhibited excellent selectivity, a low detection limit of 45 nM, and a high association constant (2.86 × 1010 M?2). Moreover, Interference experiments performed with competing metal (Ag+, K+, Cd2+, Co2+, Cu2+, Hg2+, Mn2+, Ni2+, Pb2+, Zn2+, Al3+, Cr3+, Fe3+, and Cr6+) five times greater than that of SB2 confirmed the selectivity of its sensing performance. All poly(phenoxy-imine)s displayed substantial char yields and high limiting oxygen index (LOI) values, indicating their potential as impressive flame-retardant properties (LOI ' 33 %). Furthermore, polymers P-SB1 and P-SB2 displayed blue and violet photoluminescence, respectively, under UV excitation, suggesting their utility in light-emitting materials. The novelty of this work lies in the integration of a highly selective “turn-on” fluorescent chemosensor (SB2) for Sn2+ ions with the synthesis of thermally stable, flame-retardant poly(phenoxy-imine)s, establishing a new class of multifunctional materials that combine environmental sensing capability with exceptional thermal and optical performance. © 2025 The Korean Society of Industrial and Engineering Chemistry.eninfo:eu-repo/semantics/closedAccessFluorescent sensorOxidative polycondensationPoly(phenoxy-imine)Sn2+ ionArticle10.1016/j.jiec.2025.11.0262-s2.0-105025058263Q1