Two novel anionic In-MOFs V101 and V102 were synthesized and structurally characterized. The structrual transformation from 2-fold interpenetration to noninterpenetration was completed by changing solvent from DMF to DEF. Luminescence investigations reveal that only V102 not V101 can sensitively and selectively detect traces of antibiotics nitrofurazone in water solution via an environmentally friendly manner, and the detection limit can reach to 0.2 ppm. The luminescent difference between V101 and V102 mainly originates from the divergence of interpenetration structures. Namely, through interpenetration-control, the luminescent probe can switch on or off to detect nitrofurazone. This is the first example of interpenetration-dependent MOFs-based luminescent probe.
Cyclization of propargylic alcohols with CO 2 is an important reaction in industry,a nd noble-metal catalysts are often employed to ensure the high product yields under environmentally friendly conditions.H erein ap orous noblemetal-free framework 1 with large 1D channels of 1.66 nm diameter was synthesized for this reaction. Compound 1 exhibits excellent acid/base stability,a nd is even stable in corrosive triethylamine for one month. Catalytic studies indicate that 1 is an effective catalyst for the cyclization of propargylic alcohols and CO 2 without any solvents under mild conditions,a nd the turnover number (TON) can reach to arecord value of 14 400. Furthermore,t his MOF catalyst also has rarely seen catalytic activity when the biological macromolecule ethisterone was used as as ubstrate.M echanistic studies reveal that the synergistic catalytic effect between Cu I and In III plays ak ey role in the conversion of CO 2 .
pH value is a key
parameter in reflecting the health status, reaction
process, and water quality. The construction of highly sensitive pH
luminescent ratiometric is important but challenging. Herein we designed
and synthesized a unique triple-interpenetrated luminescent lanthanide-organic
framework {[Eu(PPTA)0.5(NO3)(DMF)2]·H2O}
n
(V104) based on an amphoteric ligand 4,4′,4′′,4′′′-(1,4-phenylenebis(pyridine-4,2,6-triyl))tetrabenzoic
acid (H4PPTA). Compound V104 possesses high
solvent and acid/alkaline stabilities. Luminescent investigations
reveal that V104 exhibits dual emission peaks at 390
and 480 nm, and these two peaks can separately detect OH– and H+ among various anions and cations. Importantly, V104 can serve as a self-calibrated pH ratiometric to quantitatively
detect pH value, and the sensitivity can reach 403.2% per pH for OH–, and 129.5% per pH for H+. Furthermore,
by encapsulating magnetic γ-Fe2O3 nanoparticles
in V104, the pH sensor can be readily separated from
the analyte by external magnet and recycled at least four times, suggesting
as-synthesized γ-Fe2O3@V104 has potential for monitoring pH fluctuations in water. To our knowledge,
this is the first self-calibrated ratiometric pH-sensor based on two
responsive wave bands which can separately detect OH– and H+.
Regulating Lewis acid–base sites in catalysts to investigate their influence in the chemical fixation of CO2 is significant but challenging. A metal–organic framework (MOF) with open metal Co sites, {(NH2Me2)[Co3(μ3‐OH)(BTB)2(H2O)]⋅9 H2O⋅5 DMF}n (1), was obtained and the results of the catalytic investigation show that 1 can catalyze cycloaddition of CO2 and aziridines to give 99 % yield. The efficiency of the cyclization of CO2 with propargyl amines is only 32 %. To improve the catalytic ability of 1, ligand XN with Lewis base sites was introduced into 1 and coordinated with the open Co sites, resulting in a decrease of the Lewis acid sites and an increase in the Lewis base sites in a related MOF 2 ({(NH2Me2)[Co3(μ3‐OH)(NHMe2)(BTB)2(XN)]⋅8 H2O⋅4 DMF}n). Selective regulation of the type of active centers causes the yield of oxazolidinones to be enhanced by about 2.4 times, suggesting that this strategy can turn on/off the catalytic activity for different reactions. The catalytic results from 2 treated with acid solution support this conclusion. This work illuminates a MOF‐construction strategy that produces efficient catalysts for CO2 conversion.
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