A Luminescent Inorganic-Organic hybrid, [Cd(C16H10N2O8S)(H2O)], for the Selective and Recyclable Detection of Chromates and Dichromates in Aqueous Solution

A new inorganic organic hybrid compound [Cd(H2L)(H2O)], 1, {where, H2L2- = 4,4′-sulfonylbis(phenylene)bis(oxamate)} has been prepared under solvothermal conditions. The compound has a three dimensional structure. The compound exhibits strong luminescent behavior, which was used for the detection of chromate and dichromate anions in aqueous media at low concentrations. The compound exhibited high selectivity and recyclablity for the detection of low concentrations (ppm levels) of chromate and dichromate ions. Compound 1 was also found to be an effective catalyst for the Knoevenagel condensation involving aromatic aldehyde and malononitrile under green solvent free conditions with high yield and recyclability.