Pyridinium-based symmetrical diamides as chemosensors in visual sensing of citrate through indicator displacement assay (IDA) and gel formation

The design and synthesis of pyridinium-based symmetrical diamides 1 and 2 along with their anion binding studies through 'indicator-diplacement assay' are reported. Both the chemosensors effectively respond in in CH3CN-H2O (4: 1 v/v) at pH= 6.3 for the selective naked-eye detection of citrate. Additionally, chemosensor 2 (c = 6.29 x 10(-3) M) forms a stable gel only with citrate in CH3CN, which validates its visual sensing.