Introduction - New Synthetic Routes to Polyoxometalate Containing Ionic Liquids - page 16

1.4.2.2 POM-ILs applied for industrial processes
The application of POM-IL-3 was even further extended and a recent study has
highlighted the use of this POM-IL for the hydrothermal catalytic conversion of cellulose
into a range of useful fine chemicals, thereby demonstrating the assets of POM-ILs in
synthetic industrial processes. [52]
Another example is the deep desulfurization of model diesel fuels which has been
demonstrated using a Keggin-based POM-IL featuring the N -propanesulfone pyridinium
(PsPy + ) cation. [53] The compound, POM-IL-5 , (PsPy) 3 [PW 12 O 40 ] was employed in a three-
phase system consisting of the POM-IL as bottom layer, an aqueous hydrogen peroxide
phase as middle layer and the diesel oil as top layer. It was shown using POM-IL-5
together with a standard IL, [omim]PF 6 , almost complete oxidative removal of the
model sulphur pollutant dibenzothiophene was achieved within 1 hour at a
temperature of T = 30 ˚C. The system could be recycled several times with only marginal
loss of activity, thus demonstrating the industrial importance of this new compound
class.
1.4.2.3 Inorganic chemistry beyond the aqueous phase
Employing POMs as fully inorganic compounds with high crystal lattice energies in ionic
liquids, drastically expands their applicability as it allows dissolution in organic solvents.
POMs may thus be used as homogenous catalyst or Brønsted acids with reactions
necessitating organic media which is not or only partially possible with many
"traditional" POMs.
Beside increasing their field of application the ionic liquid medium can exhibit altered
chemical conditions and therefore change the reactivity of POMs. A remarkable
example is the photochemical oxidation of water carried out at interfaces of water with
ionic liquids in the working group of Alan M. Bond . [54] [P 2 W 18 O 62 ] 6- is photochemically
reduced in "wet" ionic liquids like 1-butyl-3-methylimidazolium tetrafluoroborate
[BMIM][BF 4 ] where water acts as an electron donor and is itself oxidized to dioxygen.
Such type of redoxreaction does not occur if the [P 2 W 18 O 62 ] 6- is dissolved in neat water