- Influence of C2-Methylation of Imidazolium Based Ionic Liquids on Photoinduced Spin Dynamics of the Dissolved ZnTPP Studied by Time-Resolved EPR
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Unusual physical properties of ionic liquids (ILs) can be implemented in many different applications and are very sensitive to the structure of IL. In this work we investigate the spin dynamics of probe molecule Zn tetraphenylporphyrin (ZnTPP) dissolved in a series of ILs using time-resolved electron paramagnetic resonance (TR EPR). We compare the TR EPR characteristics in C2-methylated imidazolium-based ILs [bmmim]BF4 and [bmmim]PF6 and in their C2-protonated analogs [bmim]BF4 and [bmim]PF6 to assess the influence of C2-methylation. The corresponding TR EPR signatures are drastically different in the two types of ILs. The analysis of experimental data allows assumptions that the ZnTPP molecule is distorted in C2-methylated ILs, contrary to other organic media and C2-protonated analogs. The mobility of ZnTPP in C2-methylated ILs is smaller compared to that in C2-protonated analogs, implying different microenvironment formed around dissolved ZnTPP.
- Ivanov, Mikhail Yu.,Prikhod'Ko, Sergey A.,Adonin, Nicolay Yu.,Bagryanskaya, Elena G.,Fedin, Matvey V.
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- Alkyl vs. alkoxy chains on ionic liquid cations
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The crystal structures and thermal behavior of the 1-(2-methoxyethyl)-2,3- dimethylimidazolium chloride and hexa-fluorophosphate salts are compared with the analogous 1-butyl-2,3-dimethylimidazolium salts to examine the influence of the ether oxygen on salt thermal properties for a typical constituent cation used in the preparation of ionic liquids. The Royal Society of Chemistry 2006.
- Henderson, Wesley A.,Young Jr., Victor G.,Fox, Douglas M.,De Long, Hugh C.,Trulove, Paul C.
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- The impact of ionic liquids on the coordination of anions with solvatochromic copper complexes
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Solvatochromic transition metal (TM)-complexes with weakly associating counter-anions are often used to evaluate traditional neutral solvent and anion coordination ability. However, when employed in ionic liquids (IL) many of the common assumptions made are no longer reliable. This study investigates the coordinating ability of weakly coordinating IL anions in traditional solvents and within IL solvents employing a range of solvatochromic copper complexes. Complexes of the form [Cu(acac)(tmen)][X] (acac = acetylacetonate, tmen = tetramethylethylenediamine) where [X]- = [ClO4]-, Cl-, [NO3]-, [SCN]-, [OTf]-, [NTf2]- and [PF6]- have been synthesised and characterised both experimentally and computationally. ILs based on these anions and imidazolium and pyrrolidinium cations, some of which are functionalised with hydroxyl and nitrile groups, have been examined. IL-anion coordination has been investigated and compared to typical weakly coordinating anions. We have found there is potential for competition at the Cu-centre and cases of anions traditionally assigned as weakly associating that demonstrate a stronger than expected level of coordinating ability within ILs. [Cu(acac)(tmen)][PF6] is shown to contain the least coordinating anion and is established as the most sensitive probe studied here. Using this probe, the donor numbers (DNs) of ILs have been determined. Relative donor ability is further confirmed based on the UV-Vis of a neutral complex, [Cu(sacsac)2] (sacsac = dithioacetylacetone), and DNs evaluated via23Na NMR spectroscopy. We demonstrate that ILs can span a wide donor range, similar in breadth to conventional solvents.
- Kuzmina,Hassan,Patel,Ashworth,Bakis,White,Hunt,Welton
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supporting information
p. 12185 - 12200
(2017/09/25)
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- A simple halide-to-anion exchange method for heteroaromatic salts and ionic liquids
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A broad and simple method permitted halide ions in quaternary heteroaromatic and ammonium salts to be exchanged for a variety of anions using an anion exchange resin (A- form) in non-aqueous media. The anion loading of the AER (OH- form) was examined using two different anion sources, acids or ammonium salts, and changing the polarity of the solvents. The AER (A- form) method in organic solvents was then applied to several quaternary heteroaromatic salts and ILs, and the anion exchange proceeded in excellent to quantitative yields, concomitantly removing halide impurities. Relying on the hydrophobicity of the targeted ion pair for the counteranion swap, organic solvents with variable polarity were used, such as CH3OH, CH3CN and the dipolar nonhydroxylic solvent mixture CH3CN:CH2Cl 2 (3:7) and the anion exchange was equally successful with both lipophilic cations and anions.
- Alcalde, Ermitas,Dinares, Immaculada,Ibanez, Anna,Mesquida, Neus
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experimental part
p. 4007 - 4027
(2012/07/28)
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- A general halide-to-anion switch for imidazolium-based ionic liquids and oligocationic systems using anion exchange resins (A- form)
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Further studies on the application of an AER (A- form) method broadened the anion exchange scope of representative ionic liquids and bis(imidazolium) systems. Depending on the hydrophobicity nature of the targeted imidazolium species and counte
- Alcalde, Ermitas,Dinares, Immaculada,Ibanez, Anna,Mesquida, Neus
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supporting information; scheme or table
p. 3266 - 3268
(2011/05/30)
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- Baylis-Hillman reaction in [bdmim][PF6] ionic liquid
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A new use of ionic liquid [bdmim][PF6] as solvent for the Baylis-Hillman reaction is presented. Unlike the commonly used [bmim][PF 6] that evidently reacts with electrophilic aldehydes under basic conditions, ionic liquid [bdmim][PF
- Hsu, Jen-Chuah,Yen, Ya-Hew,Chu, Yen-Ho
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p. 4673 - 4676
(2007/10/03)
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- Method of producing nitrile compounds
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The present invention relates to the manufacture of nitrile compounds from unsaturated organic compounds by reaction with hydrogen cyanide. It relates more particularly to the manufacture of nitrile compounds of use in the synthesis of adiponitrile, an important chemical intermediate in the manufacture of major chemical compounds, such as hexamethylenediamine and ε-caprolactam. The invention provides a process for the manufacture of organic compounds comprising at least one nitrile functional group by carrying out a hydrocyanation reaction between hydrogen cyanide and an organic compound comprising at least one ethylenic unsaturation. This reaction is carried out in the presence of a catalytic system comprising a metal element chosen from the group consisting of nickel, platinum and palladium and an organophosphorus ligand, the reaction medium additionally comprising an ionic liquid in the liquid state at least at the temperature at which the hydrocyanation reaction is carried out.
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- A Novel and Eco-friendly Method for the Preparation of Ionic Liquids
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A novel and eco-friendly method is described for the direct preparation of a series of ionic liquids containing alkylimidazolium-based cations and hexafluorophosphate-based (or tetrafluoroborate-based) anions in a one-pot procedure by using ionic liquids themselves as solvents.
- Xu, Dan-Qian,Liu, Bao-You,Luo, Shu-Ping,Xu, Zhen-Yuan,Shen, Yin-Chu
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p. 2626 - 2628
(2007/10/03)
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