Are ionic liquids and liquid coordination complexes really different? - Synthesis, characterization, and catalytic activity of AlCl3/base catalysts.

Lewis acid/base catalysts of AlCl3/N-methyl-2-pyrrolidone (O-NMP) and AlCl3/1-methylimidazole (N-Mim) were prepared and found to have higher catalytic activity in the Friedel-Crafts alkylation of benzene than the known super acidic ionic liquid chloroaluminate [HN222][Al2Cl7] ([HN222]+ = triethylammonium). Crystals structures were obtained for AlCl3(N-Mim), [AlCl2(O-NMP)2][AlCl4], and [Al(O-NMP)6][AlCl4]3·(C6H6)3 supporting the assignments of neutral and charged catalytic species.