Three coordination networks of Cd(II) with 2-hydroxy-trimesic acid and their photoluminescence properties

•Three cadmium coordination polymers have been synthesized by using rigid carboxylic ligand.•The bidentate auxiliary ligands with different lengths have an important influence on their final structures.•Compound 1 might be developed as a functional luminescent probe for detecting both nitrobenzene and Fe3+. With a rigid carboxylic acid ligand, 2-hydroxy-trimesic acid (H4L), coordination polymers {[Cd3(L)2(H2O)6]·4H2O}n (1), [Cd2(H2L)2(pdp)0.5(µ-H2O)]n(2) azobispridine (pdp) and [Cd(4,4ʹ-bipy)2(H2O)2]n·[H2L]n (3) 4,4’-bipyridine (4,4’-bipy) were synthesized. Compound 1 is a three-dimensional network of linear trinuclear clusters [Cd3(μ2-COO)2(μ1-COO)2]. Compound 2 can be simplified as a 3.12-connected 3-nodal net with a new topological point symbol of {4.52}4{416.516.626.88}. Compound 3 features a two-dimensional grid cationic architecture with rectangle channels encapsulating [H2L]2− anions. The powder X-ray diffraction, the thermal stabilities, and solid-state luminescence properties were studied for 1–3. Furthermore, compound 1 shows high selectivity and sensitivity for detecting both NB and Fe3+. Three cadmium complexes with rigid carboxylic acid ligands have been synthesized. The bidentate auxiliary chain nitrogenous ligands with different lengths play an important role to affect their final structures. The luminescent sensing of compounds 1 toward nitrobenzene and Fe3+ has also been investigated [Display omitted]