Fluorescence Enhancement of a Metal-Organic Framework for Ultra-Efficient Detection of Trace Benzene Vapor.

Indoor detection of volatile organic compounds (VOCs) concentration is necessary due to the serious toxicity hazards even at trace level. However, physisorbents usually exhibit weak interactions especially in the presence of trace concentrations of VOCs, thus exhibiting poor responsive signal. Herein, we report a new flexible metal-organic framework (MOF) that exhibits interesting pore-opening behavior after immersing in H2 O. The pore-opening phase shows significant (≈116 folds) and extremely fast (<1 minute) fluorescence enhancement after being exposed to saturated benzene vapor. The limit of detection concentration for benzene vapor can be calculated as 0.133 mg L-1 . Thus this material represents the first MOF to achieve visual detection of trace benzene vapor by the naked eyes. Theoretical calculations and single-crystal structure reveal that the special "bilateral π-π stacking" interactions between the host and guest, which facilitate electron transfer and greatly enhance the intensity of fluorescence.

Boosting the degradation of antibiotics via peroxymonosulfate activation with a Cu-based metal-organic framework.

Highly efficient degradation of antibiotics is a huge challenge due to the extremely stable molecules and the potential for biological resistance. However, conventional degradation methods are limited to lower degradation rate, higher energy consumption and secondary pollution. Herein, we report a new Cu-based metal-organic framework (MOF), featuring classical planar trinuclear [Cu3(µ3-O)]4+ clusters within the pores. The presence of the rich open metal sites and the large pore ratio, as well as the high catalytic activity of Cu2+ ions, are conducive to boosting the degradation of various antibiotics (>95%) under the activation of peroxymonosulfate. Remarkably, this is the first MOF to achieve such exceptional catalytic performance under neutral and even alkaline conditions, which exceeds those of most reported materials. Mechanism investigation demonstrates that multiple active species were produced and promoted the degradation synergistically during the advanced oxidation processes.

A series of naphthalenediimide-based metal-organic frameworks: synthesis, photochromism and inkless and erasable printing.

Three new three-dimensional metal-organic frameworks were synthesized based on a naphthalenediimide derivative ligand, all of which exhibit photochromic behaviour due to the presence of the naphthalenediimide core. Interestingly, two of them possess significant colour changes under light, excellent stability, and appropriate photochromic lifetimes, thus showing potential for application in inkless and erasable printing media.