Three Luminescent Cd(Ii) Coordination Polymers as Highly Sensitive and Selective Sensors for Detection of Cr2o72– Oxoanions in Water

Three Cd(II) coordination polymers (CPs), {[Cd(TCPA)(L)]·H 2 O} n ( 1 ), {[Cd(1,2-BDC)(L)]·H 2 O} n ( 2 ) and [Cd(1,3-BDC)(L) 0.5 (H 2 O)] n ( 3 ) (L = 1,3-bis(5,6-dimethylbenzimidazol-1-yl)propane, H 2 TCPA = 2,3,5,6-tetrachloroterephthalic acid, 1,2-H 2 BDC = 1,2-benzenedicarboxylate and 1,3-H 2 BDC = 1,3-benzenedicarboxylate) were hydrothermally synthesized and characterized. 1 features a 2D {4 4 } structure, which constructs a 3D supramolecular structure through π - π stacking interactions. 2 shows a 1D ladder-like chain which is additional extended into a 3D supramolecular network via two different types of π-π stacking interactions. 3 retains a 2D (3,4)-connected 3,4L83 net which can be broadened into a 3D supramolecular structure by O–H···O hydrogen bonds. Both 1 , 2 and 3 could serve as efficient probes for detecting of Cr 2 O 7 2– anions with high quenching efficiency ( K sv) values (7820 M –1 for 1 , 9460 M –1 for 2 and 20018 M –1 for 3 , separately) and low detection limit (0.42 μM for 1 , 0.37 μM for 2 and 0.15 μM for 3 , respectively)