SUPPORTED IONIC LIQUIDS BY CHEMICAL BONDS

The first example of SILP-catalysis was the fixation of an acidic chloroaluminate ionic liquid on an inorganic support. The acidic anions of the ionic liquid, [AI2CI7] and [AI3CI10], react with free OH-groups of the surface to create an anionic solid surface with the ionic liquid cations attached [72]. The catalyst obtained was applied in the Friedel-Crafts acylation of aromatic compounds. Later, the immobilisation of acidic ionic liquids by covalent bonding of the ionic liquid cation to the surface was developed and applied again in Friedel-Crafts chemistry [73]. 

Analysis of the surface coverage revealed an average of 0.4 ionic liquid fragments nm 2, corresponding to the involvement of approximately 35% of all the hydroxyl groups of the pre-treated silica gel. 

To introduce the Rh-centre in the supported ionic liquid, a solution of [Rh(CO)2(acac)] in acetonitrile was treated with either the ligand tri(m-sulfonyl)triphenyl phosphine trisodium salt (TPPTS) or the ligand tri(m-sulfonyl)triphenyl phosphine tris(l- butyl-3-methyl-imidazolium) salt (TPPTI) (Rh/P ratio of 1 10). The ligand TPPTI was found to dissolve in [BMIM][BF4] and 

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