Pore Wall-Functionalized Luminescent Cd(II) Framework for Selective CO₂ Adsorption, Highly Specific 2,4,6-Trinitrophenol Detection, and Colorimetric Sensing of Cu²⁺ Ions

Abstract

Astute combination of basic functionality and luminescence property can pursue multifunctional metal−organic frameworks (MOFs) with assorted applications such as selective CO 2 adsorption, specific detection of explosive nitro compounds, and toxic metal ion sensing. The bifunctional ligand 4-(4-carboxyphenyl)-1,2,4-triazole (HL) is used to build the framework [Cd(L) 2 ]•(DMF) 0.92 (1) (L = L −1 , DMF = N,N′-dimethylformamide), having a free N atom decorated porous channel. The solvothermal synthesis is extended to produce three isoskeletal frameworks in diverse solvents, where pore size maximizes in 2 by employing N,N′-diethylformamide solvent. The activated framework [Cd(L) 2 ] exhibits strong CO 2 affinity with good CO 2 /N 2 selectivity, and shows minimum CO 2 loss during five adsorption−desorption cycles. Sensing studies for nitro-aromatic compounds in DMF reveal highly specific detection of 2,4,6-trinitophenol (TNP) with remarkable quenching (K SV = 9.3 × 10 4 M −1 ) and low limit of detection (LOD: 0.3 ppm). The quenching mechanism is ascribed to the combined existence of static and dynamic quenching plus resonance energy transfer. The activated framework further shows highly selective luminescent detection of Cu 2+ ions with a quenching constant of 4.4 × 10 3 M −1 and very low LOD of 3.9 ppm. The detection of Cu 2+ ions accompanies a visible color change in solution and solid phase, which validates the present system as a potential colorimetric Cu 2+ sensor. Of note is that bifunctional sensor shows excellent reusability toward TNP and Cu 2+ detection. Overall, selective and multicycle CO 2 adsorption, together with efficient sensing of both TNP and Cu 2+ ion, manifest this pore-functionalized MOF as a versatile material for sustainability.

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.…”

Moisture stability of ethane‐selective Ni(II), Fe(III), Zr(IV)‐based metal–organic frameworks

“…And ΔH s value of ethane for Zr‐bptc is slightly higher than that of ethane for UiO‐66 (26.4 kJ/mol), PCN‐245 (23.0 kJ/mol), and Ni(bdc)(ted) 0.5 (21.5 kJ/mol) . The performance of desorption regeneration is a crucial standard to assess an adsorption material . Compared with other MOFs with high ΔH s value, Zr‐bptc with lower ΔH s means that this material will be easier for the desorption regeneration.…”

Three new coordination polymers based on bis(4-(4H-1,2,4-triazol-4-yl)phenyl)methane: syntheses, structures, multiresponsive luminescent sensitive detection for antibiotics and pesticides, and antitumor activities

“…A variety of CPs-based luminescence sensors were synthesized for the aim of detecting metal cations, aromatic explosives and organic pollutants. [31][32][33] In the past several decades, antibiotics and pesticides originally used in the medical and agricultural elds have emerged as one of typical stubborn organic pollutants in water, simple and convenient methods for their effective recognition is fully meaningful. The design of luminescence sensing materials represents an attractive way to efficiently detect such organics.…”