With the purpose of exploring the catalytic and sensing properties of crystalline materials, two coordination polymers were rationally constructed by the reactions of Zn(II)/Cd(II) ions with methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate (H2L) and bis(4-pyridylformyl)piperazine (bpfp) mixed ligands. Compound 1 features a 2D layered structure and compound 2 shows a 2D + 2D → 3D inclined polycatenation structure. Due to the presence of uncoordinated carbonyl moieties, the two CPs exhibit effective heterogeneous Lewis base catalytic activities to Knoevenagel condensation, and compound 1 shows higher catalytic activity than compound 2 under the same reaction conditions. Interestingly, the two CPs display strong ligand-based photoluminescence both in the solid state and in aqueous solution. More importantly, the sensing test results indicate that compound 2 as a sensor material can selectively recognize L-cysteine through the luminescence quenching effect.
