A micrometer-sized europium(iii)–organic framework for selective sensing of the Cr₂O₇²⁻ anion and picric acid in water systems

Abstract

A micrometer-sized europium(iii)-organic framework with asymmetric binuclear metal subunits extended by 4,5-dichlorophthalaten (DCPA), [Eu(HO)(DCPA)], was easily obtained using a reverse microemulsion method. The framework exhibits good dispersibility, excellent thermal and environmental stability and easy regeneration ability. More importantly, the complex displays strong red emission and can selectively and sensitively detect both inorganic CrO anions (K = 8.7 × 10 M) and organic picric acid contaminants (K = 1.07 × 10 M) in water systems through fluorescence quenching. A luminescent film of 1 was further prepared and successfully used to detect the CrO anion in an aqueous system. These interesting results indicate that the well-dispersed europium(iii)-organic framework can serve as a promising dual-responsive luminescent sensor for environmental pollutant monitoring.

A stable pillared metal–organic framework constructed by H4TCPP ligand as luminescent sensor for selective detection of TNP and Fe3+ ions

“…The plot can be well‐fitted by the Stern–Volmer (S–V) equation ( I o / I = 1 + K sv [M]) in a low concentration range (Figure c). The quenching constant is 6.95 × 10 4 M –1 at low concentration, which can be compared with the previously reported fluorescence‐based MOF materials for detecting TNP, for example, {[Zn( μ ‐HCIP)( μ ‐pbix)]·2H 2 O} n (4.37 × 10 4 M –1 ), [Eu 2 (H 2 O)(DCPA) 3 ] n (1.07 × 10 4 M –1 ), [Zn 5 (DpImDC) 2 (DMF) 4 (H 2 O) 3 ]·H 2 O·DMF (1.0 × 10 5 M –1 ), CSMCRI‐1 (4.6 × 10 4 M –1 ), [Zn(L)] n (3.1 × 10 4 M –1 ) [Cd(L) 2 ]·(DMF) 0.92 (9.3 × 10 4 M –1 ), and Rh6G@1 (4.1 × 10 4 M –1 ) . The limit of detection (LOD) for TNP is also calculated using the following formula: where σ is the standard deviation of initial fluorescence intensity of Zn‐TCPP/BPY and K is the slope of the aforementioned linear curve.…”

3D Cadmium(II)‐Based Coordination Polymer Constructed from V‐Shaped Semirigid Ligand: Selective Detection of Oxoanion Pollutants CrO42–, Cr2O72–, MnO4– in Water

“…Hence, a quenching mechanism due to the collapse or decomposition of the CP can be ruled out. Secondly, the fast and simple regeneration of 1 excludes the possibility of a charge‐transfer‐based quenching . Another possible reason is the competition of the excitation absorptions between the host framework and anions.…”

Solvo‐thermal Preparation of One Novel Cadmium(II) Coordination Polymer with 1‐(4‐Aminobenzyl)‐1,2,4‐Triazole and Bi‐functional Photo‐Luminescent Sensing for Acetone and Dichromate

“…Although some spectroscopic and analytical strategies have been utilized for Cr 2 O 7 2– discrimination, to the best of our knowledge, the luminescent probes base on the aromatic conjugated triazole derivative for convenient and fast detection of Cr 2 O 7 2– pollutants is still scarcely reported. As listed Table , a comparison about K sv and detection limits between sensor 1 and related CP sensors for Cr 2 O 7 2– detection also has been made, it can be seen that the K sv and detection limits of sensor 1 can be compared with previous reports, therefore 1 also can be considered as the limited reported example of 2D triazole‐Cd II photo‐luminescent probes, which can be developed as the new discriminating materials for Cr 2 O 7 2– in aqueous solutions.…”