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Updated: Oct 6, 2025
Surface Functionalization of Metal-Organic Frameworks for Improved Moisture Resistance
Published on: September 5, 2018
Crystal Packing-Driven Selective Hg(II) Ion Sensing Using Thiazolothiazole-Based Water-Stable Zinc Metal-Organic
Akashdeep Nath1, Gegari M Thomas1, Shivali Hans2
1School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala 695551, India.
Abstract:
A soft acid-soft base interaction is highly predictable. However, we demonstrate how the crystal packing of the newly synthesized zinc framework [Zn2(5-AIA)2(DPTTZ)]·DMF (where 5-AIA = 5-aminoisophthalic acid, DPTTZ = N,N'-di(4-pyridyl)thiazolo-[5,4-d]thiazole, DMF = N,N'-dimethylformamide) directs an unexpected interaction between the soft acid Hg(II) and the hard base oxygen instead of having a soft center like nitrogen and sulfur in the system attributed to a strong solvent interaction and a favorable ionic radius of Hg(II) ion for oxygen chelation. This engenders selective Hg(II) ion sensing through a "turn-off" emission quenching in water (limit of detection = (2.174 ± 0.06) × 10-9 M) along with natural water resources and in a broad pH range. A quantum-chemical calculation elucidates the turn-off quenching mechanism and favorable Hg(II) interaction with encompassed oxygen atoms inside the framework.
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