Two new Pb (II) ‐based coordination polymers (CPs) with chemical formulas, Pb (L 1) 2 (H 2 O) n (CP 1) and Pb (L 2) (DMF) n (CP 2), were synthesized under solvothermal conditions using adamantane‐1‐carboxylic acid (HL 1) and 5‐nitroisophthalic acid (H 2 L 2) as organic linkers. Single‐crystal X‐ray diffraction shows that CP 1 adopts a 1D chain structure built from mixed chelating/bridging μ 4 ‐adamantane carboxylates and aqua ligands, while CP 2 forms a robust 2D sheet network supported by μ 3 / μ 4 carboxylate modes of H 2 L 2 L 2 2‐ and coordinated DMF. Photophysical studies reveal ligand‐centered enhanced fluorescence upon coordination to Pb (II), attributed to framework‐induced rigidity of the HL 1 and π ‐conjugated H 2 L 2 linkers. Both CPs show negligible response toward metal ions, anions, and amino acids. However, they display highly selective fluorescence quenching toward acetone. Both CP 1 and CP 2 exhibit low detection limits (LOD) of 24. 22 μM and 3. 32 μM, respectively. Stern–Volmer analysis, complemented by density functional theory calculations, indicates that acetone‐induced quenching is attributed to a photoinduced electron transfer (PET) pathway, facilitated by the energy‐level alignment and weak host–guest interactions including possible hydrogen bonding between acetone and the framework of CPs 1 and 2. Notably, both CP 1 and CP 2 are recyclable over five cycles with minimal loss in the sensing activity.
Sharma et al. (Thu,) studied this question.