Preparation of multilayer films containing a crown heteropolyanion and an osmium functionalised pyrrole monomer

Investigating Cation Binding in the Polyoxometalate‐Super‐Crown [P8W48O184]40−

“…This considerable electron-storage capability, combined with the unique stability of the {P 8 W 48 } heteropolyanion, confers effective catalytic properties, as demonstrated in the reduction of nitrites. [8] Over the past decade, the initial indifference of the POM community towards {P 8 W 48 } has been redressed, with a number of papers published concerning transition-metal substitution, [10] transition-metal-linked networks, [11] electrochemistry, [12] and vesicle-like "blackberry" formation. [13] However, this relative explosion of interest has created an imbalance, with the fundamental physical properties of the heteropolyanion rarely addressed.…”

“…Crystallographically, this is observed by a lengthening of hydrogen bonds in 1 b compared with those in 1 a [5] showing the positions of internal potassium ions, located at regular sites within the cavity. At 12,3,6, and 9 o'clock, are located eight half-occupancy sites of the hinge positions, bridging {P 2 W 12 } subunits. Other key K + binding sites lie directly between these positions on the nucleophilic faces of the {P 2 W 12 } subunits.…”

Redox, surface and electrocatalytic properties of layer-by-layer films based upon Fe(III)-substituted crown polyoxometalate [P8W48O184Fe16(OH)28(H2O)4]20-

“…Polyoxometalates have previously been employed for the reduction of nitrite [62] and hydrogen peroxide [34,63,64]. Here the electrodes modified with LBL films with both outer layers were investigated for the electrocatalytic reduction of nitrite and hydrogen peroxide.…”

“…The growth of such films on solid surfaces has been monitored by cyclic voltammetry [16,20,22,31,[34][35][36], UV -Vis absorption spectroscopy [16,20,22,30,35,36] or impedance spectroscopy [20]. The LBL films have then been characterised by electrochemical quartz crystal microgravimetric technique [16], SEM [36,37], AFM [22,30,31,38], XPS [22,31,38], fluorescence spectroscopy [37], FTIR spectroscopy [30] and electron spin resonance techniques (ESR) [22].…”

Electrocatalysis by crown-type polyoxometalates multi-substituted by transition metal ions; Comparative study

“…Indeed, it can accommodate transition metals or lanthanide ions [12][13][14][15][16][17] and reveals electrocatalytic activity towards the reduction of nitrite [18] and hydrogen peroxide [19]. Also, Fe 3+ - [20], Co 2+ -and Ni 2+ -substituted [21,22] P8W48 anions revealed independent metal ion centres available for redox switching.…”