Two anionic metal-organic frameworks with tunable luminescent properties induced by cations

A New Zn(II) Compound: Luminescent Property and Promoting Knee Cartilage Repair by Modulating Iron Death

The hydrothermal reactions of bis{6-{5-methyl-1 H,7 H-[1,2,4]triazolo[1,5-a]pyrimidin-7-one}}methane (L) and Zn(NO3)2·6H2O at 180 ℃ afforded a novel Zn(II) coordination polymer (CP), that is, {[Zn2(L)(µ2-O)2]·3H2O}n (1), which further characterized via Single crystal X-ray diffraction (SCXRD), elemental analysis (EA), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA). Besides, this CP reveals strong luminescence that may be caused by the charge transfer within the ligand. In biological study, the new compound was evaluated for its protective effect on chondrocytes. This compound significantly up-regulated GPX4 and down-regulated HO-1 mRNA levels, thereby inhibiting iron death in chondrocytes.

Dual Function Based on Switchable Colorimetric Luminescence for Water and Temperature Sensing in Two-Dimensional Metal-Organic Framework Nanosheets

A simple, rapid, highly selective, and real-time determination of water is urgently required for preventing danger from water contamination in materials. Herein, the excited-state proton transfer (ESPT) concept-based luminescent sensor [Cd₂(2,5-tpt)(4,5-idc)(H₂O)₄] (1) (2,5-tpt = 2,5-dihydroxyterephthalic acid and 4,5-idc = 4,5-imidazoledicarboxylic acid) has been designed for discriminative detection via enol-keto tautomerism. To improve the sensitivity, two-dimensional (2D) nanosheets of 1 have been synthesized by top-down liquid ultrasonic exfoliation technology for sensing water in dimethylformamide, which lead to fast detection (<30 s), high selectivity, broad-range detection (0-50% v/v), and a low detection limit value (0.25% v/v). This sensor can serve dual sensing mechanisms along with a luminescent color change via shifted emission (green→yellow) in low water content and a turn-off method in high water content. For ease of use, the test-strip paper-based 2D nanosheets of 1 have been prepared and applied for water detection with long-term stability, pH stability, and good reusability. On-site water detection in real time can be evaluated using a smartphone color-scanning application for quantitative scanometric assays coupled with test-strip paper-based 2D nanosheets of 1. Also, 1 can be utilized for a colorimetric luminescent thermometer in the ranges of physiological and high temperature with good linearity and recyclability.