Four new Zn/Cd coordination polymers constructed by the asymmetrical N-heterocyclic rigid carboxylate: Synthesis, crystal structure, photoluminescence and sensing properties.

Abstract Four new coordination polymers, namely, [Zn 2 (L) 2 (1,3-bdc)(H 2 O) 2 ] n (1) , [Cd 2 L 2 (Cl) 2 ] n ·0.5nH 2 O (2) , [Cd 2 L 2 (adip)] n ·2nH 2 O (3) , and [CdLCl] n (4) were solvothermally synthesized by reaction of Zn(NO 3) 2 ·6H 2 O, CdCl 2 ·H 2 O with an asymmetrical rigid N-heterocyclic carboxylatic acid (HL), where HL = 1-(4-carboxylphenyl)-3-(prazin-2-yl)-1H-1,2,4-triazole, 1,3-bdc = benzene- 1,3-dicarboxylic acid, H 2 adip = adipic acid, H 2 glu = glutaric acid. Compound 1 is a 1D ladder chain. Compound 2 is a (3,6)-connected network with the Point symbol of (42·6) 2 (44·62·88·10). Compound 3 displays a intriguing (3,3,4,4)-connected topological net with the Point symbol of (4·64·8)(4·72)(42·6·72·9)(42·6). Compound 4 presents a new (3,5)-connected topological net with the Point symbol of (3·4·5)(32·4·5·62·74). In addition, the thermal stabilities and photoluminescence properties of these compounds were also studied. Dramatically, compound 3 shows the high selectivity and sensitivity for Fe3+ cation via a luminescence quenching effect. Graphical abstract In this paper, we have synthesized four new Zn/Cd compounds based on HL, namely, [Zn 2 (L) 2 (1,3-bdc)(H 2 O) 2 ] n (1) , [Cd 2 L 2 (Cl) 2 ] n ·0.5nH 2 O (2) , [Cd 2 L 2 (adip)] n ·2nH 2 O (3) , [CdLCl] n (4). Meanwhile, the luminescence properties and thermal stabilities of 1 – 4 were also studied. Compound 3 shows the high selectivity and sensitivity for Fe3+ cation, via a luminescence quenching effect. fx1 Highlights • Four new coordination polymers were solvothermally synthesized. • HL ligand displays multiple coordination modes. • Compound 3 shows the high selectivity and sensitivity for Fe3+ cation. [ABSTRACT FROM AUTHOR]