Fluorescence Turn-On/Off Responses of In(Ⅲ)-MOF to Short-Chain Perfluorocarboxylic Acids

Short-chain perfluorocarboxylic acids(PFCAs) are a class of persistent organic pollutants that are widely used as substitutes for long-chain PFCAs. However, they also pose a non-negligible risk to ecosystems. In this study, we demonstrated that a fluorescent metal–organic framework(MOF)(named V-101) constructed from In^(3+)and an aromatic-rich tetratopic carboxylate ligand 5-[2,6-bis(4-carboxyphenyl) pyridin-4-yl] isophthalic acid(H4BCPIA) exhibited highly efficient turn-off and turn-on fluorescence responses toward five short-chain PFCAs in water and methanol, respectively. The limits of detection of V-101 toward five short-chain PFCAs are down to μg/L level, and it showed good anti-interference abilities toward short-chain PFCAs in the presence of common metal ions. The major mechanisms associated with fluorescence responses were molecular collisions and interactions between V-101 and short-chain PFCAs. This work demonstrates that the structure variety of MOFs imparts them with the potential of MOFs in the detection of short-chain PFCAs for pollution control.

Seed-aided green synthesis of metal-organic frameworks in water

Green synthesis of metal-organic frameworks(MOFs)in water with alleviated environmental influence and reduced cost is an essential step to transfer laboratory MOFs research to industrial application.Switching from the commonly used organic solvents to pure water encounters challenges of the poor solubility of organic linkers,slow reaction kinetics,and the formation of polymorphic products.So far,a universal MOFs synthetic strategy in water system has yet to be developed.This study reports the seed-aided synthesis of eleven MOFs with diverse compositions and structures while pure water serving as solvent.The corresponding reaction temperature and time of using this new strategy were reduced compared with original synthetic approaches,while the products maintain porous structure and high crystallinity.The success of this strategy relies on the addition of parent MOFs as seeds which could promote crystallization process by skipping the time-consuming induction period and avoiding the formation of polymorphic impurities.

An anionic In(Ⅲ)-based metal-organic framework with Lewis basic sites for the selective adsorption and separation of organic cationic dyes

In this paper, a new anionic metal-organic framework, [In(PBPTTBA)][(CH_3)_2 NH_2](BUT-29) has been synthesized through the reaction of tetratopic acid ligand with double Lewis pyridine sites, 4,4',4'',4'''-(4,4'-(1,4-phenylene)bis(pyridine-6,4,2-triyl)) tetrabenzoic acid(H_4 PBPTTBA) and In(NO_3)_2·5H_2O and fully characterized by single-crystal X-ray diffraction(SXRD), powder X-ray diffraction(PXRD),thermogravimetric analysis(TGA), infrared spectroscopy(IR), and elemental analysis(EA). BUT-29 can be used as an efficient adsorbent for the selective removal of organic cationic dyes in N,N0-dimethylformamide(DMF) solution. The adsorption capacities of BUT-29 toward methylene blue and crystal violet at 298 K can reach 1119 mg/g and 832 mg/g, respectively. Moreover, the adsorbed dyes can be released in the DMF solution of LiNO_3 gradually.