Syntheses, crystal structures and electrochemical properties of two new supramolecular compounds based on hexamolybdates and crown ethers

摘要

Two new supramolecular compounds based on hexamolybdates and crown ethers, (Na(Benzo-15-crown-5)(H2O)(CH3CN)](2)Mo6O19 1 and [Na(Dicyclohexyl-18-crown-6)](2)Mo6O19 2 have been synthesized and characterized by elemental analysis, IR, TG, single crystal Xray diffraction and electrochemical analysis. There are dominantly the electrostatic interactions between the crown ether-Na+ complex cations and the Mo6O192- polyanions in the compounds. In 2, the Mo6O192- anions are packed in the AB center dot center dot center dot AB layers along the c axis and the nearest O-t...O-t distances of neighboring Mo6O192- anions in the A layers are shorter than those in the B layers. The POM-crown ether supramolecular compounds have been used as the bulk-modifier to fabricate the chemically modified carbon paste electrodes (MCPE) successfully. They display well-defined cyclic voltammograms with three two-electron reversible redox couples in acidic aqueous solution, electrocatalytic activities toward the reduction of hydrogen peroxide and good stability due to their insolubility.