Polytorsional-amide/carboxylates-directed Cd(II) coordination polymers exhibiting multi-functional sensing behaviors

By rational assembly of polytorsional-amide [N,N'-bis(4-methylenepyridin-4-yl)-1,4-naphthalene dicarboxamide (L)] and polytorsional-carboxylates [H(2)ADI = adipic acid, H2PIM = pimelic acid, H2SUB = suberic acid], three new Cd-based coordination polymers (CPs) C30H30CdN4O7 (1), C31H32CdN4O7 (2) and C31.03H30.55CdCl0.24N4O5.52 (3) were successfully synthesized. CPs 1-2 and 3 are 2D networks and a 3D framework, which all display 3,5-connected topologies with different structural details. The effects of carboxylates with different carbon chains on the structure of the complexes were studied. Fluorescence experiments show that CPs 1-3 have good multi-functional sensing ability for metal cations (Fe3+), anions (MnO4-, CrO42-, Cr2O72-) and organochlorine pesticides (2,6-dichloro-4-nitroamine) with good anti-interference and recyclable characteristics. The possible sensing mechanism is also investigated in detail.