Zr(IV)-Based Metal-Organic Framework with T-Shaped Ligand: Unique Structure, High Stability, Selective Detection, and Rapid Adsorption of Cr₂O₇^2– in Water

Abstract

Dichromate is known for severe health impairments to organisms. New and valid strategies have been developed to rapidly detect and efficiently remove this pollutant. Constructing stable luminescent metal-organic frameworks (MOFs) for dichromate recognition and removal from aqueous solution could provide a feasible resolution to this problem. Herein, a new luminescent Zr(IV)-MOF, ZrO(OH)(HO)(BTBA) (BUT-39, BUT = Beijing University of Technology) was constructed through the reaction of a newly designed functionalized T-shaped ligand 4,4',4″-(1 H-benzo[ d]imidazole-2,4,7-triyl)tribenzoic acid (HBTBA) with zirconium salt. BUT-39 has a unique porous framework structure, in which Zr cluster acts as a rare low-symmetric 9-connected node and BTBA as a T-shaped 3-connected linker. As far as we know, this represents the first case of a (3,9)-connected Zr(IV)-MOF. BUT-39 could retain its framework integrity in boiling water, 2 M HCl aqueous solution, and pH 12 NaOH aqueous solution. Due to its good water stability and strong fluorescent emission, BUT-39 is then employed in fluorescence sensing for various ions in aqueous solution and shows good performance toward CrO selectively, at a low concentration and a short response time (<1 min). Simultaneously, it also exhibits excellent capacity to rapidly capture CrO (within 1 min) with a high uptake up to 1 mmol g. Taking advantage of its excellent stability, sensitive and selective sensing, as well as rapid and high adsorption, BUT-39 is expected to be useful in CrO detection in and removal from water.

A stable zirconium based metal-organic framework for specific recognition of representative polychlorinated dibenzo-p-dioxin molecules

“…Through the rational design of the ligands and the connectivity of Zr 6 clusters, the Zr-MOFs with expected structure can be constructed. In this work, firstly, we checked the sensing abilities of several Zr-MOFs with different framework structures and pore sizes including UiO-66 33 , BUT-39 34 , BUT-12 35 , BUT-66 36 , BUT-15 37 , NU-1000 32 , and NU-1003 38 toward BCDD (Supplementary Figs. 1–7).…”

Two zinc(ii) coordination polymers based on flexible co-ligands featuring assembly imparted sensing abilities for Cr2O72− and o-NP

“…5b and 6c).The uorescent quenching efficiency was then quantitatively evaluated by the Stern-Volmer equation, I 0 /I ¼ K sv [M] + 1, where I 0 and I are the maximum luminescent intensities before and aer the addition of the probe, [M] is the molar concentration of probe solution, and K sv is the quenching constant (M À1 ). [43][44][45][46][47] As shown in Fig. 6b indicating the high sensitivity of complexes 1-2 for sensing Cr 2 O 7…”

Nanotrap Grafted Anion Exchangeable Hybrid Materials for Efficient Removal of Toxic Oxoanions from Water

“…Reported capture studies have been focused mostly on storage capacity ( Figures S45–S47 and Table S19 ) so far in the literature, but very little attention has been paid to the selectivity in the presence of excessive competitive anions, which is equally important for realistic applications. 40 By virtue of the rapid and efficient oxoanion adsorbing behavior of the material, treatment of Cr(VI)-contaminated wastewater was performed, by mimicking the real-time scenario. We conducted a chromatographic column exchange experiment and observed that the Cr(VI) concentration in the column eluted water was well below (<50 ppb) its permitted drinking water level suggested by USA-EPA ( Figures S48–S51 and Videos S3 and S4 ).…”