Soft Ionization of Thermally Evaporated Hypergolic Ionic Liquid Aerosols

Isolated ion pairs of a conventional ionic liquid, 1-Ethyl-3-Methyl-Imidazolium Bis(trifluoromethylsulfonyl)imide ([Emim+][Tf2N?]), and a reactive hypergolic ionic liquid, 1-Butyl-3-Methyl-Imidazolium Dicyanamide ([Bmim+][Dca?]), are generated by vaporizing ionic liquid submicron aerosol particles for the first time; the vaporized species are investigated by dissociative ionization with tunable vacuum ultraviolet (VUV) light, exhibiting clear intact cations, Emim+ and Bmim+, presumably originating from intact ion pairs. Mass spectra of ion pair vapor from an effusive source of the hypergolic ionic liquid show substantial reactive decomposition due to the internal energy of the molecules emanating from the source. Photoionization efficiency curves in the near threshold ionization region of isolated ion pairs of [Emim+][Tf2N?]ionic liquid vapor are compared for an aerosol source and an effusive source, revealing changes in the appearance energy due to the amount of internal energy in the ion pairs. The aerosol source has a shift to higher threshold energy (~;;0.3 eV), attributed to reduced internal energy of the isolated ion pairs. The method of ionic liquid submicron aerosol particle vaporization, for reactive ionic liquids such as hypergolic species, is a convenient, thermally ?cooler? source of isolated intact ion pairs in the gas phase compared to effusive sources

Biphasic Ni-Catalyzed Ethylene Oligomerization in Ionic Liquids

Diimine nickel complexes activated with aluminoxane in chloroaluminate ionic liquids are highly active catalysts either for the biphasic ethylene oligomerization or for polymerization depending on the bulkiness of the diimine ligand. The activation of Ni(0) with a Brönsted acid in different non-chloroaluminate ionic liquids is also reported. The nature of the ionic liquid and the presence or not of a nitrogen ligand affect significantly the catalytic performances. The olefinic products are weakly soluble in ionic liquids and can be separated from the catalytic ionic phase by simple decantation. The nickel catalysts are immobilized and stabilized in the ionic liquids and can be recycled

Chloroaluminate Ionic Liquids: from their Structural Properties to their Applications in Process Intensification

The structural properties of new organochloroaluminate ionic liquids based on mixtures of (Ethyl)nAlCl$_{(3-n)}$ (n = 1 to 3) with 1-methyl-3-butyl-imidazolium chloride (BMIC) have been studied by Raman spectroscopy. With this technique, the mono and polynuclear anions present in these melts have been identified and quantified. The mixed salts formed with AlCl3 and EtAlCl2 or [ EtAlCl2 and Et2AlCl] together with BMIC are also considered. All behave as regular chloroaluminates; in particular, their acid-base properties depend on their compositions. Thanks to this study, it has been possible to anticipate and to optimize the composition of an ionic liquid based on EtAlCl2, with the aim of performing industrially the Ni-catalyzed olefin oligomerization in chloroaluminates. The influence of the solvent composition on the overall mechanism of the catalysis is now basically understood. The resulting ionic liquids play the dual role of solvents and nickel activator (or co-catalyst)

Oligomerization of Monoolefins by Homogeneous Catalysts

In this article are summarized the different mechanistic pathways for the oligomerization of monoolefins by homogeneous catalysts, particularly for ethylene and alpha olefins. The major topics are: the production of non regioselective and also regioselective olefin dimers, the production of linear alpha olefins by ethylene oligomerization as well as the selective dimerization of ethylene and its selective trimerization. Several industrial developments initiated by IFP are presented to illustrate this topic