Manganese-phosphomolybdate molecular catalysts for the electron transfer reaction of ferricyanide to ferrocyanide

Abstract

¼ 1,3-bi(4pyridyl)-propane) have been constructed and characterized. The inorganic moieties of the three hybrids consist of 'hourglass-shaped' anionic clusters, composed of two reduced polymolybdenum phosphate units [P 4 V Mo 6 V O 28 (OH) 3 ] 9 {P 4 Mo 6 } bridged by one manganese ion. Preliminary experiments show that these hybrids, as a unique class of molecular catalyst, are highly active for promoting the inorganic electron transfer (redox) reaction of ferricyanide to ferrocyanide by thiosulphate with high rate constants under mild conditions. These catalysts maintain their structural identity both in solution and solid state and can be easily separated from the reaction solution for the next catalytic cycle.

Highly Efficient Photoreduction of Low‐Concentration CO2to Syngas by Using a Polyoxometalates/RuIIComposite

“…The one peaking at 240 and 307 nm may be attributed to pπ (Oterminal) →dπ* (Mo) electronic transitions in the Mo=O bond and dπ–pπ–dπ electronic transitions between the energetic levels of the Mo−O−Mo bond. The moderate absorption bands in the range 450–620 nm are ascribed to coordinated Co II whereas the weak and broad bands at 600–700 nm are typical absorptions coming from reduced polyoxoanions . The optical absorption spectrum of the composite (Figure b, red curve) exhibits characteristic peaks of both [Co 20 Mo 16 P 24 ] 4− and [Ru(bpy) 3 ] 2+ , which leads to the wide and high adsorption of visible light.…”

“…The moderatea bsorption bands in the range 450-620 nm are ascribed to coordinated Co II whereas the weak and broad bands at 600-700 nm are typical absorptions coming from reduced polyoxoanions. [35][36][37] The optical absorption spectrum of the composite (Figure 2b (Figure 2c). Considering the reported highesto ccupied molecular orbital( HOMO) and lowest unoccupied molecular orbital( LUMO) energy levels of [Ru(bpy) 3 ]Cl 2 are À5.68 and À3.19 eV (versus vacuum level; Figure 2d), [38] the band alignment between [Ru(bpy) 3 ]Cl 2 and Co 2 [Co 20 Mo 16 P 24 ]w ill facilitatet he photoinduced electron transfer.…”

Reduced Phosphomolybdates as Molecular Catalysts for Hexavalent Chromium Reduction

“…[21] All the reagents were commercially purchased and used without further purification. FTIR spectra were recorded in KBr pellets with a FTIR-8900 IR spectrometer in the range of 400-4000 cm -1 .…”

“…Our recent work described three manganese-containing phosphomolybdate hybrids: (H 2 bpp) 5 [21] The three hybrids were built upon hourglass-type {Mn[P 4 Mo 6 ] 2 } units surrounded by protonated bpp cations. The hybrids were also shown to be catalytically active as heterogeneous molecular catalysts for the electron-transfer reaction of ferricyanide to ferrocyanide.…”

“…6 } polyhedra link each other in a manner of corner-and edge-sharing modes ( Figure 1). [21] Hydrogen bonding and van der Waals interactions are the main contributors to the noncovalent contacts that exist in 1-3. [30] In addition, there are complex O-H···O interactions between the anionic clusters and water molecules, as well as the N-H···O and C-H···O interactions between organic cations and inorganic anions.…”