Tight binding and fluorescent sensing of oxalate in water.

A dinuclear copper complex that binds tightly and selectively to oxalate over other dicarboxylates like malonate, succinate, and glutarate has been developed. This receptor can be used for fluorescent detection of oxalate in water at physicological pH by chemosensing ensemble approach. Crystal structure of oxalate bound to the receptor together with molecular mechanics and DFT computations provide insights into the tight and selective binding of the anion by the receptor.