Hybrid Organic-Inorganic Materials Based on Polyoxometalates and Ionic Liquids and Their Application in Catalysis

Abstract

An overview of the recent advances in the field of polyoxometalate, ionic liquid hybrids, is proposed with a special attention paid to their application in catalysis, more precisely biphasic and heterogeneous catalysis. Both components of the hybrids are separately outlined pointing to their useful properties and potential for catalysis, followed by the description of the hybrids preparation and synergy between components in a large range of organic transformations. And finally a vision on the future developments is proposed.

Colorimetric determination of total phenolic contents in ionic liquid extracts by paper microzones and digital camera

“…18 ILs have been proposed as greener alternatives to volatile organic solvents because of their unique characteristics, such as negligible vapour pressure, good thermal stability, wide liquid range, good dissolving and extracting ability, excellent microwave-absorbing ability, designable structures, etc. [23][24][25] POMs are a class of anionic metal-oxygen clusters built by the connection of [MO] x polyhedra of the early transition metals in their highest oxidation states. The simplest technique for quantication of extracted phenols is the spectrophotometric assay.…”

2‐Methyl‐1,3‐disulfoimidazolium polyoxometalate hybrid catalytic systems as equivalent safer alternatives to concentrated sulfuric acid in nitration of aromatic compounds

“…Thus combining all their structural changes and newly added unique physical/chemical properties of ionic liquids makes POMs water‐tolerant and recyclable heterogeneous catalysts. This concept of organic–inorganic hybrids has been employed to synthesize a new class of task‐specific ionic liquid‐based POM salts by pairing of anionic POMs with or without functional group‐tethered organic cations . The presence of Brønsted acidic functional groups (e.g.…”

Influence of the ionic liquid presence on the selective oxidation of glucose over molybdenum based catalysts

“…The ILs are compounds consisting in ions with melting points below 100 • C whose principal advantages could be resumed in high ionic mobility, good electric conductivity, low vapor pressure and good thermal and chemical stability [18,19]. Most commonly used ILs are composed by quaternary ammonium salts or cyclic amine salts [20]. They have already found its application in catalysis as a solvents [21][22][23][24] in electrochemistry [25] and organic synthesis, however, the use of the ionic liquid as a part of hybrid catalyst is barely studied [20,[26][27][28][29][30].…”

“…On the other hand the polyoxometalates, well-known catalytically active compounds were also considered as a potential glucose transformation catalysts [20]. In particular, the Keggin-type polyoxometalates, classified as anionic metal-oxygen clusters of the early transition metals, appear as a good candidates for carbohydrate conversion [31][32][33].…”

“…Additionally, the substitution of all the protons with organic cations could results in a new class of organic-inorganic hybrid materials which takes advantages on both inorganic (strength, thermal stability and chemical resistance) and organic part (lightness, flexibility and versatility) features. Perfect example of organic cations which could be applied in the hybrid are those of ionic liquids (ILs) [20,[37][38][39].…”