A super water-stable europium–organic framework: guests inducing low-humidity proton conduction and sensing of metal ions

Abstract

The ordered dimethylammonium cations [H2N(CH3)2](+) and helical water spirals as guest species make a super water stable europium-organic framework possess a proton conductivity of over 10(-3) S cm(-1) at 68% relative humidity. A fluorescent probe for Fe(3+) and Cu(2+) ions via a different mechanism has also been realized.

A luminescent Terbium-Succinate MOF thin film fabricated by electrodeposition for sensing of Cu2+ in aqueous environment

“…However, these quenched films can recover most of its original luminescence back via treated with Na 2 EDTA weak solution (see SI for details). These results suggested that partial ion-exchange might occur in the framework according to previously reported literatures [12,13].…”

“…However, most MOFs are unstable in water, which strictly limited their sensing application in practical case [12]. The stability of Tb-SA films were investigated via time-dependent luminescence intensity analysis of strongest 5 D 4 → 7 F 5 emission at 545nm for 30 minutes, as illustrated in Fig.4.…”

“…In particular, Eu(III) MOFs and Tb(III) MOFs with carboxylic organic ligands are considered most useful in practical application due to their visible red/green characteristic luminescence as well as long luminescence lifetimes [11]. Until now, various types of lanthanide metal-organic frameworks in sensing of metal ions [12][13][14], anions [15], gas molecules [16,17], nitro explosives [18][19][20], small molecules [21][22][23][24][25][26] and temperature [27] have been realized and reported. However, most of them are brittle crystals or loose powders synthesized by hydrothermal/solvothermal methods and require specific solvent condition to detect analyte, which strictly limited their in-field application.…”

Insights into the Fluorescence Sensing Mechanism of Scandium‐Based Metal‐Organic Frameworks by Solid‐State NMR Spectroscopy

“…The quenching on fluorescent MOFs by metal ions can be mainly caused by (1) the MOF structure being collapsed by the metal ion inbreak; (2) ion exchange occurrence between the metal nodes and the incoming cations; and (3) strong interaction between incoming metal ions and luminophores in the MOFs . In this case, to gain insights into the fluorescence sensing mechanism of Sc 2 (NH 2 ‐BDC) 3 in the selective detection of Ni 2+ and Co 2+ ions from molecule level, XPS, FTIR, EPR and ssNMR are utilized to reveal the interaction between the framework of Sc 2 (NH 2 ‐BDC) 3 and Ni 2+ /Co 2+ ions.…”

Structural characterization of three semi-rigid tetracarboxylate-containing transition-metal coordination polymers

“…Metal-multicarboxylate CPs not only possess the rich structures [6][7][8][9][10], many interesting physical properties have also been investigated [11][12][13][14][15][16][17][18][19][20]. For example, (i) porous metal-multicarboxylate CPs can selectively adsorb gases, in particular H 2 (for energy storage) and CO 2 (for purification of the environment) [21][22][23][24][25]; (ii) Zn 2+ /Cd 2+ /Ln 3+ -multicarboxylate CPs can emit light.…”