Solvo‐thermal Preparation and Characterization of Two Cd II Coordination Polymers Constructed From 2,6‐(1,2,4‐Triazole‐4‐yl)pyridine and 5‐R‐Isophthalic Acid (R = Nitro, Sulfo)

Under the solvo‐thermal conditions, two novel Cd II mixed‐ligand coordination materials with 2,6‐(1,2,4‐triazole‐4‐yl)pyridine(L 1 ) and aromatic poly‐carboxylic acid co‐ligands such as 5‐R‐isophthalic acid (R = nitro, sulfo), namely [Cd(L 1 )(NO 2 ‐BDC)(H 2 O) 2 ] · 2H 2 O ( 1 ) and [Cd(L 1 )(HSIP)(H 2 O)] · 4H 2 O ( 2 ) (NO 2 ‐H 2 BDC = 5‐nitroisophthalic acid, H 3 SIP = 5‐sulfobenzene ‐isophthalic acid) were successfully prepared. These Cd II mixed‐ligand coordination polymers 1 – 2 have been measured by crystal X‐ray analysis, FT‐IR spectra and powder X‐ray diffraction analyses. In 1 , these seven‐coordinate Cd II atoms (Cd1) are inter‐linked by didentate 5‐nitroisophthalic acid ligands forming 1D chain structures. In 2 , these L 1 and partially de‐pronated HSIP 2– are inter‐linked by central Cd II centers and are arranged into the unique 2D micro‐porous metal‐organic framework of 2 . Side view of 2 , it is noted that numerous oxygen atoms of un‐coordinated carboxylate groups and coordinated SO 3 groups protrude out and decorate the 2D framework of 2 . PXRD patterns of 1 and 2 sample is tested, which is consistent with the simulated PXRD diffraction pattern. Photoluminescence studies show that 2 is highly selective and sensitive to trace elements of Eu 3+ with excellent K sv value (7.86 × 10 4 m – 1 ) and low detection limit (5.56 × 10 –2 mM), which also provides a convenient method and platform for real‐time detection of Eu 3+ .