In order for Ionic Liquids (ILs) to be utilized to their full potential, it is necessary to have a complete understanding of their physical properties, including phase transitions temperatures1.

We have previously reported into the extent of structuring of ILs using photochromic molecular probes, and investigated the appropriate IL water content to yield hydrated IL systems for analysis of polarity and to create environments suitable for effective enzyme activity 1,2,3.

In this study we investigated interactions in hydrated ILs containing variable hydrophobic and hydrophilic regions through optical and thermal analysis. The enthalpies and phase transitions of the systems were compared, between the temperature range -50°C to +30°C for the ILs with varying degrees of hydration. Reichardtʼs dye was used as a molecular probe to monitor changes in interactions in the ILs as a function of temperature. Comparisons were made between ILs and for ILs with varying degrees of hydration. Spectroscopic studies were performed using Perkin Elmer UV-Visible Spectrometer and phase transitions monitored using a Perkin Elmer Differential Scanning Calorimeter.

The ILs examined are; Trihexyltetradecylphosphonium Chloride [P6,6,6,14 Cl] Tributyl-tetradecylphosphonium Chloride, [P4,4,4,14 Cl], 1-Ethyl-methyl-3-imidazolium-ethyl Sulfate [Emim][EtSO4] and Trihexyltetradecylphosphonium Dicyanamide [P6,6,6,14 DCA].

1. Robert Byrne, Simon Coleman, Simon Gallagher, and Dermot Diamond. Designer Molecular Probes for Phosphonium Ionic Liquids. Physical Chemistry Chemical Physics, 2010.

2. Kyoko Fujita, Douglas R. MacFarlane, Maria Forsyth, Masahiro Yoshizawa-Fujita, Kenichi Murata,† Nobuhumi Nakamura, and Hiroyuki Ohno*,Solubility and Stability of Cytochrome c in Hydrated Ionic Liquids: Effect of Oxo Acid Residues and Kosmotropicity, 2007.

3. SergeiV.DzyubaandRichardA.Bartsch,Expandingthepolarityrange of ionic liquids, Tetrehedron Letters, 2002

Byrne, Robert

Coleman, Simon

Diamond, Dermot

Fraser, Kevin J.

Gallagher, Simon

English

In order for Ionic Liquids (ILs) to be utilized to their full potential, it is necessary to have a complete understanding of their physical properties, including phase transitions temperatures1.
We have previously reported into the extent of structuring of ILs using photochromic molecular probes, and investigated the appropriate IL water content to yield hydrated IL systems for analysis of polarity and to create environments suitable for effective enzyme activity 1,2,3.
In this study we investigated interactions in hydrated ILs containing variable hydrophobic and hydrophilic regions through optical and thermal analysis. The enthalpies and phase transitions of the systems were compared, between the temperature range -50°C to +30°C for the ILs with varying degrees of hydration. Reichardtʼs dye was used as a molecular probe to monitor changes in interactions in the ILs as a function of temperature. Comparisons were made between ILs and for ILs with varying degrees of hydration. Spectroscopic studies were performed using Perkin Elmer UV-Visible Spectrometer and phase transitions monitored using a Perkin Elmer Differential Scanning Calorimeter.
The ILs examined are; Trihexyltetradecylphosphonium Chloride [P6,6,6,14 Cl] Tributyl-tetradecylphosphonium Chloride, [P4,4,4,14 Cl], 1-Ethyl-methyl-3-imidazolium-ethyl Sulfate [Emim][EtSO4] and Trihexyltetradecylphosphonium Dicyanamide [P6,6,6,14 DCA].
1. Robert Byrne, Simon Coleman, Simon Gallagher, and Dermot Diamond. Designer Molecular Probes for Phosphonium Ionic Liquids. Physical Chemistry Chemical Physics, 2010.
2. Kyoko Fujita, Douglas R. MacFarlane, Maria Forsyth, Masahiro Yoshizawa-Fujita, Kenichi Murata,† Nobuhumi Nakamura, and Hiroyuki Ohno*,Solubility and Stability of Cytochrome c in Hydrated Ionic Liquids: Effect of Oxo Acid Residues and Kosmotropicity, 2007.
3. SergeiV.DzyubaandRichardA.Bartsch,Expandingthepolarityrange of ionic liquids, Tetrehedron Letters, 2002

Irish Universities

Physico-chemical properties of ionic-liquid water mixtures

In order for Ionic Liquids (ILs) to be utilized to their full potential, it is necessary to have a complete understanding of their physical properties, including phase transitions temperatures1.\ud
We have previously reported into the extent of structuring of ILs using photochromic molecular probes, and investigated the appropriate IL water content to yield hydrated IL systems for analysis of polarity and to create environments suitable for effective enzyme activity 1,2,3.\ud
In this study we investigated interactions in hydrated ILs containing variable hydrophobic and hydrophilic regions through optical and thermal analysis. The enthalpies and phase transitions of the systems were compared, between the temperature range -50°C to +30°C for the ILs with varying degrees of hydration. Reichardtʼs dye was used as a molecular probe to monitor changes in interactions in the ILs as a function of temperature. Comparisons were made between ILs and for ILs with varying degrees of hydration. Spectroscopic studies were performed using Perkin Elmer UV-Visible Spectrometer and phase transitions monitored using a Perkin Elmer Differential Scanning Calorimeter.\ud
The ILs examined are; Trihexyltetradecylphosphonium Chloride [P6,6,6,14 Cl] Tributyl-tetradecylphosphonium Chloride, [P4,4,4,14 Cl], 1-Ethyl-methyl-3-imidazolium-ethyl Sulfate [Emim][EtSO4] and Trihexyltetradecylphosphonium Dicyanamide [P6,6,6,14 DCA].\ud
1. Robert Byrne, Simon Coleman, Simon Gallagher, and Dermot Diamond. Designer Molecular Probes for Phosphonium Ionic Liquids. Physical Chemistry Chemical Physics, 2010.\ud
2. Kyoko Fujita, Douglas R. MacFarlane, Maria Forsyth, Masahiro Yoshizawa-Fujita, Kenichi Murata,† Nobuhumi Nakamura, and Hiroyuki Ohno*,Solubility and Stability of Cytochrome c in Hydrated Ionic Liquids: Effect of Oxo Acid Residues and Kosmotropicity, 2007.\ud
3. SergeiV.DzyubaandRichardA.Bartsch,Expandingthepolarityrange of ionic liquids, Tetrehedron Letters, 2002

Name not available

!"#$%&'#()*+,--%.%*/!0-#"***!***/!0-#"*+#()*!"#$%&'#()***!***()"/1--*"1(#,"1-*#"'(#(!(%**INTRODUCTION •  Investigations into the thermophysical properties and extent of nano-structuring of ionic liquids using photochromic responsive dyes have yielded hydrated IL systems for polarity analysis and created environments suitable for effective enzyme activity.1,2 •  In this study we investigate hydrated ILs containing hydrophillic and hydrophobic regions through Raman spectroscopy and thermal analysis.  •  The ILs investigated were Trihexyltetradecylphosphonium Chloride [P6,6,6,14][Cl] Tributyl-tetradecylphosphonium Chloride, [P4,4,4,14][Cl], 1-Ethyl-methyl-3-imidazolium-ethyl Sulfate [C2mIm][EtSO4] and Trihexyltetradecylphosphonium Dicyanamide [P6,6,6,14][DCA].  Figure 1. Cations and Anions used in this study •  The aim of this investigation was to analyze the changes in peak intensities and peak positions of the cation and anion of the ILs after the addition of water. Looking at hydrogen interactions between water and the anion of the ILs. And to see if these interactions manifest a change in the melting point of these systems. EXPERIMENTAL •  All of the ILs studied were commercially available (CYTEC, Sigma-aldrich)3. The IL/water systems were prepared using a weight ratio of 1:1. Regarding impurities the ILs were purified using previously published techniques4, in order to prevent acidic impurities protonating the phenolate ion of the Reichardt’s dye. •  The Raman spectra was measured in the spectra range 600-3200 cm-1 at a resolution of 1 cm-1.This accounted for all the characteristic peaks of the ILs, displaying any changes of the system after the addition of water. •  UV-Vis spectroscopy was performed between the range of 400-900 nm at a resolution of 2 cm-1.The concentration of Reichardt’s dye used was 10-4 M. The dye was used to locate specific domains that had been formed as a result of specific interactions between the water and the IL. •  Thermal scans were measured between the temperature range -50 oC to +30 oC at increments of 1,10 and 20 oC/min. The thermal characteristics of the ILs were analyzed to monitor any change after the addition of bulk water. Physico-chemical Properties of Ionic-Liquid Water Mixtures •  Symmetrical stretch of sulphate occurs in narrow region  •  When mixed with H2O the symmetry is distorted due to interactions  &2324*'56789:;7:5<*=C2mIm>=%8',?>*&2324*'56789:;7:5<*':@AB3*/0'1*SOCH2(CH2)10CH3OOHOH•  NaDBSA used as a derivative to compare with sulphate stretch of [C2mIm][EtSO4], shows more symmetrical peak when mixed with H2O, due to more structured solvation. •  Na+ is more hydrophillic than C2mIm+ so forms a more structured solvation shell than [C2mIm][EtSO4] !$C$#'*'56789:;7:5<*=C2mIm>=%8',?>*0.15 0.17 0.19 0.21 0.23 0.25 0.27 0.29 450 470 490 510 530 550 570 590 610 630 650 Absorbance (%) Wavelength (nm) EMIM ETSO4 & H2O EMIM EtSO3 •  Bathochromic shift of IL/ H2O mix shows specific solvation. •  The IL head groups coordinates with H2O creating specific regions. •  Shows a reduction in the interaction between Reichardt’s dye and the IL (Fig 1).  [C2mIm][EtSO4] 542nm [C2mIm][EtSO4]+H2O 550nm (bathochromic shift) Results and Discussion                Simon Gallagher, Robert Byrne, Kevin Fraser, Simon Coleman and Dermot Diamond CLARITY, National Centre for Sensor Research Dublin City University, Glasnevin, Dublin 9, Ireland +:47DB;A:4*•  UV-VIS: Using Riechardt’s Dye, [C2mIm][EtSO4] is seen to experience a bathochromic shift when mixed with water. Polar H2O coordinating with head-groups of IL, forming specific solvation shells, leading to reduction of the stabilization ground state of Reichardt’s dye.5  •  Raman: Sulphate symmetrical stretch of [C2mIm][EtSO4] becomes unsymmetrical when mixed with H2O, showing interactions at head-group of IL  DSC: Coordinating of ionic head-groups with H2O shows structural changes by shifting of melting points of , [C2mIm][EtSO4]. REFERENCES 1.  Robert Byrne, Simon Coleman, Simon Gallagher, and Dermot Diamond. Designer Molecular Probes for Phosphonium Ionic Liquids. Physical Chemistry Chemical Physics, 2010. 2.  Kyoko Fujita, Douglas R. MacFarlane, Maria Forsyth, Masahiro Yoshizawa-Fujita, Kenichi Murata,† Nobuhumi Nakamura, and Hiroyuki Ohno*,Solubility and Stability of Cytochrome c in Hydrated Ionic Liquids: Effect of Oxo Acid Residues and Kosmotropicity, 2007. 3.  www.cytec.com, www.sigmaaldrich.com 4.  ˇK. J. Fraser, E. I. Izgorodina, M. Forsyth, J. L. Scott and D. R. MacFarlane, Chem. Commun., 2007, 3817-3819. 5.   Christian Reichardt, Polarity of ionic liquids determined empirically by means of solvatochromic pyridinium N-phenolate betaine dyes. Green Chemistry, 2005 PC6H13 C6H13C6H13C14H29NNNCCNN[P6,6,6,14]+ [C2mIm]+ [EtSO4]- [DCA]- •  After the addition of H2O to [C2mIm][EtSO4t], the above graph clearly shows that there is a shift of the ILs melting point. •  This shows that the interactions occurring at a molecular level between the IL and the solvent are manifested physically in the shifting of the ILs  melting point and change of transition enthalpy. Figure 1. (a) IL anions (orange) and cations (yellow) interacting with Reichardt’s dye. (b) Addition of H2O and formation of solvation shell to mediate dissolution of probe dye an IL interaction with water. Reduced interaction with dye results in bathochromic shift in dye Lmax.  Acknowledgements  •  Dr. Steven Bell from Queen’s University, Belfast for providing very helpful advice towards the project. •  Science Foundation Ireland, grant code 07/CE/I1147 [C2mIm][EtSO3] H2O [C2mIm][EtSO3]  H2O RD !max = 542nm RD !max = 550nm SOOO OSO OOOOHHOHHE2F*+-  +  +  +  +  +  -  -  -  -  -  -  -  -  -  -  -  +  +  +  +  +  +  +  +  +  +  +  +  -  -  -  -  -  - -  +  +  +  +  +  -  -  -  -  -  -  -  -  -  -  -  +  +  +  +  +  + H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O  + H2O H2O H2O H2O  - H2O H2O H2O H2O  +  +  +  +  -  - H2O H2O H2O +H2O +(a) (b) 

DCU Online Research Access Service

Designer Molecular Probes for Phosphonium Ionic Liquids. Physical Chemistry Chemical Physics,

Masahiro Yoshizawa-Fujita, Kenichi Murata,† Nobuhumi Nakamura, and Hiroyuki Ohno*,Solubility and Stability of Cytochrome c in Hydrated Ionic Liquids: Effect of Oxo Acid Residues and Kosmotropicity,

Polarity of ionic liquids determined empirically by means of solvatochromic pyridinium N-phenolate betaine dyes. Green Chemistry,

http://doras.dcu.ie/16385/2/COIL_POSTER.pdf

Physico-chemical properties of ionic-liquid water mixtures

Abstract

Similar works

Full text

Available Versions

Irish Universities

Name not available

DCU Online Research Access Service