Room-temperature ionic liquids complexation study

So far, there have been few published simulation studies of room-temperature ionic liquids, although a number of groups have started programs in this area. Simulations of molecular liquids have been common for thirty years and have proven important in clarifying our understanding of molecular motion, local stmcture and thermodynamics of neat liquids, solutions and more complex systems at the molecular level [1 ]. There have also been many simulations of molten salts with atomic ions [5]. Room-temperature ionic liquids have polyatomic ions and so combine properties of both molecular liquids and simple molten salts. 

A study of the use of room temperature ionic liquids as a new class of nonaqneous solvents for 2-phase catalytic hydrocarbon transformations. The liquids investigated were mixtures of quartemary ammonium salts and organo-aluminum componnds. They were found to be very effective solvents for metal-catalyzed olefin dimerization and metathesis reactions. Their complexing ability and acidity can be tuned as re-... 

Chaumont, A., Wipff, G. (2004), M3+ Lanthanide Chloride Complexes in "Neutral" Room-Temperature Ionic Liquids. A Theoretical Study, J. Phys. Chem A 108, 3311-3319. 

In order to probe the potential use of room temperature ionic liquids (RTILs) as media for transition metal-based catalysts, a study comparing the displacement rate of an RTIL with those for conventional solvents, each coordinated to a transitional metal center, has been undertaken. " It had been noted that kinetic studies of such reactions of RTILs have not been reported. The system chosen was the chromium complex [(C6H6)Cr(CO)3], since it is readily converted by ultraviolet photolysis to [(C6Hg)Cr(CO)2(solv)]. ... 

A wide variety of metals can be electrodeposited from room-temperature ionic liquids. The electrodeposition mechanisms of transition metals, lanthanides and Group 13 metals have been investigated as have cobalt,iron, manganese," tin," gold, " " silver, " palladium, " mercury, cerium, and lead, and the actinides. In addition, ionic liquids have been used extensively to study the electrochemistry and spectrochemistry of metal-chloride complexes. ... 

Chaumont A, Wipff G (2005) Solvation of fluoro and mixed solvation of fluoro and mixed fluoro/chloro complexes of Eulll in the [BMIMliPFg] room temperature ionic liquid. A theoretical study. Phys Chem Chem Phys 7 1926-1932... 

Hu, Z. Huang, X. Armapureddy, H. V. R. Margulis, C. J. (2008). Molecular dynamics study of the temperatme-dependent optical Kerr effect spectra and intermolecular dynamics of room temperature ionic liquid 1-methoxyethylpyridinium dicyanoamide. Journal of Physical Chemistry B, 112, 7837-7849 Hunt, N. T. Jaye, A. A. Meech, S. R. (2007). Ultrafast dynamics in complex fluids observed through the ultrafast optically-heterodyne-detected optical-Kerr-effect (OHD-OKE), Physical Chemistry Chemical Physics, 9, 2167-2180 Hyun, B.-R. Dzyuba, S. V. Bartsch, R. A. Quitevis, E. L. (2002). Intermolecular dynamics of room-temperature ionic liquids femtosecond optical Kerr effect measurements on l-alkyl-3-ethylimidazoliinn bis((trifluoromethyl)sulfonyl)imides. Journal of Physical Chemistry A, 106, 7579-7585. 

Seddon, K.R. Stark, A. Torres, M-J. (2000) Influence of chloride, water and organic solvents on the physical properties of ionic liquids, PureAppl. Chem., 72 in o-13jSJ. Shimojo, K. Goto, M. (2004) Solvent Extraction and Stiip>ping of Silver Ions in Room-Temperature Ionic Liquids Containing Calixarenes, AnnZ. Chem. 76 5039-5044. Smetana, A.J. Popov, A.I. (1980) Lithium-7 Nuclear Magnetic Resonanoe and Calorimetric Study of Lithium Crown Complexes in Various Solvents, J. Solut. Chem., 9 183-196. Song, X. Li, H. Li, J. Liu, J. Li, Z. Liu, S. Li, C. Wu, P. (2005) The study on the coordination equilibiimn of Cu + -ethylenediamine in ionic liquid. Polymer Preprints, 46 842. 

In this study, at first a series of nickel(II)-triphenylphosphine complexes with derivatives of A-(2-pyridyl)-N -(salicylidene)hydrazine (NiLl-NiL5) were prepared and catalytic activity of complexes was studied in ethyl-methylimidazolium (emim) at room temperature. The results show that this method is very useful for the oxidation of aromatic, aliphatic, and allylic alcohols to their corresponding carbonyl compounds in a conversion range of 60-96%. The catalytic activity of complexes notably varies with the size of the substituents. It was observed that the activity decreases with increase in the bulkiness of the substituents. This may be due to steric hindrance causes by the substituent, which can affect the planarity of the ligand in the complexes. Further, ionic liquid ethyl-methylimidazolium (emim) was recycled up to 90% along with the catalyst. Both ionic liquid and catalyst could be reused at least for ten times. 

The authors of this study demonstrated that similar species, along with an unidentified one, were present during the Mizoroki-Heck reaction. It was proved that isolated trans-90 behaved as an efficient catalyst for this reaction. Finally, when [bmim] [BF4] was used as the starting material, no palladium carbene complex was obtained. This observation might explain why Mizoroki-Heck reactions proceed more quickly in halide ionic liquids than in non-coordinating ones such as PFe salts. Ultrasound-promoted formation of carbene palladium complexes can also allow their in situ preparation at room temperature. ... 

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