Novel Schiff-base derivatives and corresponding Eu(III) complexes: multiple-color, pH-responsive mechanism and fluorescence property

Schiff base compounds as fluorimetric pH sensor: a review

“…29,33,41,42 There are several examples also where Schiff base pH sensor molecules are found to consist of a phenolic hydroxyl group. 26,27,29,30,[32][33][34][35][36][38][39][40][41][42][43][44][45][46][47] In a low pH region, in the pH sensor Schiff base compounds containing heterocyclic aromatic rings, the heteroatoms generally get protonated. On the other hand, where there is a phenolic hydroxyl group within the structure of the Schiff base pH sensor, the hydroxyl group gets deprotonated in a basic medium.…”

“…Hu et al reported the synthesis and characterization of methoxypicolinohydrazide based Schiff base molecules. 43 These Schiff base molecules were observed to exhibit pH sensing properties. The authors reported that these Schiff base molecules show distinct emissive characteristics in the alkaline pH range.…”

“…It has been observed over the last two decades that Schiff base pH sensor compounds mainly contain either heterocyclic aromatic rings within its structure or specific functional groups attached to the aromatic rings. 23–47 There are also numerous examples where half condensed Schiff base compounds are found to exhibit pH sensing properties and uncondensed aldehyde groups remain intact. 29,33,41,42 There are several examples also where Schiff base pH sensor molecules are found to consist of a phenolic hydroxyl group.…”

Multifunctional Luminescent 3D Ln-MOFs with High Sensitivity for Trace Detection of Micronutrients

“…10 In addition, Ln 3+ in trivalent states, such as Eu 3+ and Tb 3+ , have obtained extensive attention because of their high color purity, fluorescence efficiency, diverse coordination environments, and high sensitivity. 11,12 In conclusion, it is a novel and feasible design strategy to construct Ln-MOFs by combining ligands with metal ions Ln 3+ . However, the fluorescence detection of Ln-MOFs materials is still in the preliminary stage.…”

“…Ln 3+ was sensitized by the three-wire states to increase luminescence, ensuring stronger emission than free ions. , Effective emission depends on the energy gap between the ligand’s singlet and triplet states, and there will be a stringent restriction on the gap between the ligand’s triplet states and the excited state of the Ln 3+ ion . In addition, Ln 3+ in trivalent states, such as Eu 3+ and Tb 3+ , have obtained extensive attention because of their high color purity, fluorescence efficiency, diverse coordination environments, and high sensitivity. , In conclusion, it is a novel and feasible design strategy to construct Ln-MOFs by combining ligands with metal ions Ln 3+ . However, the fluorescence detection of Ln-MOFs materials is still in the preliminary stage.…”