Multiresponsive luminescent sensors for antibiotics and CrVI with two luminescent ZnII/CdII coordination complexes

Two new ZnII/CdII luminescent coordination polymers (CPs) based on the V-shaped bis(imidazole) ligand 3,6-bis (1H-benzo[d]imidazol-1-yl)-9-methyl-9H-carbazole (bbimc) with [1,1 '-biphenyl]-4,4 '-dicarboxylic acid ligand (H2bpdc) have been synthesized under solvothermal conditions: {[Zn(bbimc)(bpdc)]center dot DMF center dot 2.5H2O} (CP 1), {[Cd (bbimc)(bpdc)]center dot 2DMF} (CP 2). CP 1 and CP 2 both display a uninodal 4-c unimodal sql topology 2D framework with vertex symbols of {44 center dot 62}. In addition, the two identical 2D nets of CP 2 were interpenetrated each other to form a 2D + 2D -* 3D and generate a 2-fold interpenetrating architecture. Moreover, sensing investigations of CP 1 and CP 2 revealed that both of compounds can be used as a highly sensitive and selective multi-responsive luminescent sensor for sensing Cr2O72- , CrO42- and antibiotics (TC: Tetracycline; CTC: Chlortetracycline) in H2O by exhibiting fluorescence quenching with significant quenching constants (Ksv = 1.369 x 104 M-1 (Cr2O72- ), 2.003 x 104 M-1 (CrO42- ), 5.343 x 104 M-1 (TC), 8.706 x 104 M-1 (CTC) for CP 1 and 4.452 x 104 M-1 (Cr2O72- ), 2.119 x 104 M-1 (CrO42- ), 4.175 x 104 M-1 (TC), 1.257 x 105 M-1 (CTC) for CP 2). The detection limit are 0.67 mu M (Cr2O72- ), 0.48 mu M (Cr2O72- ), 0.23 mu M (TC), 0.14 mu M (CTC) for CP 1 and 0.28 mu M (Cr2O72- ), 0.54 mu M (CrO42- ), 0.31 mu M (TC), 0.098 mu M (CTC) for CP 2, respectively. In addition, the probable fluorescence