A Molecular Simulation Study
Supporting Information
What Determines CO2 Solubility in Ionic Liquids? A Molecular Simulation Study Marco Klähn,1* Abirami Seduraman2 1
Institute of Chemical and Engineering Science, Agency for Science, Technology and Research,
1 Pesek Road, Jurong Island, Singapore 627833 2
Institute of High Performance Computing, Agency for Science, Technology and Research, 1
Fusionopolis Way, #16-16, Connexis, Singapore 138632, Rep. of Singapore
*To whom correspondence should be addressed. Phone: (65) 67963946. E-mail: [email protected]
Table S1: Comparison of Measured and Calculated Mass Densities of ILsa
ILs
ρexp [mol/l]
ρcalce [mol/l]
BMIM-PF6a
4.811-2
4.691
BMIM-BF4a
5.331, 3
5.161
BMIM-NO3b
5.764
5.621
BMIM-NTF2a
3.435-6
3.491
BMIM-Clb
6.177-8
6.031
C6MIM-NTf2b
3.079
3.061
C8MIM-PF6a
3.643
3.491
C2OHMIM-BF4b
6.1110
5.971
C6F9MIM-NTf2c
3.5611
3.581
MOEMIM-BF4d
5.7312
5.501
a
At T = 298 K and P = 10 bar.
b
At T = 298 K and P = 1 bar.
c
Saturated with CO2 at T = 298 K and P = 11.1 bar.
d e
At T = 293 K and P = 1 bar. Statistical uncertainties of the last digit are given as subscripts.
Figure S1: Structural formulas of all considered cations (left hand side) and anions (right hand side) in simulations together with their abbreviations used in the text.
Figure S2a: Atomistic partial charges used in force fields for the ions in BMIM-PF6, BMIMBF4, BMIM-NO3, and BMIM-NTf2. The partial charges are based on the electrostatic potential of the ions (ESP charges) in the actual liquid phase of the corresponding IL, derived with the CHELPG scheme.13 Charges of chemically equivalent atoms were averaged. Partial charges are given in units of the elementary charge.
Figure S2b: Atomistic partial charges used in force fields for the ions in BMIM-Cl, C6MIMNTf2, and C8MIM-PF6. The partial charges are based on the electrostatic potential of the ions (ESP charges) in the actual liquid phase of the corresponding IL, derived with the CHELPG scheme.13 Charges of chemically equivalent atoms were averaged. Partial charges are given in units of the elementary charge.
Figure S2c: Atomistic partial charges used in force fields for the ions in C2OHMIM-BF4, C6F9MIM-NTf2, and MOEMIM-BF4. The partial charges are based on the electrostatic potential of the ions (ESP charges) in the actual liquid phase of the corresponding IL, derived with the CHELPG scheme.13 Charges of chemically equivalent atoms were averaged. Partial charges are given in units of the elementary charge.
Figure S3: Distribution of empty space in pure C2OHMIM-BF4 (top) and when saturated with CO2 (bottom) in a cross section of a sample structure of the equilibrated IL. Regions of empty space were located with XCav and are shown in orange. CO2 is displayed in green. Ions and CO2 are shown in the van der Waals representation.
Figure S4: Distribution of empty space in pure C6MIM-NTf2 (top) and when saturated with CO2 (bottom) in a cross section of a sample structure of the equilibrated IL. Regions of empty space were located with XCav and are shown in orange. CO2 is displayed in green. Ions and CO2 are shown in the van der Waals representation.
References 1.
2.
3.
4. 5.
6.
7.
8.
9.
10.
11. 12. 13.
Jacquemin, J.; Husson, P.; Mayer, V.; Cibulka, I., High-Pressure Volumetric Properties of Imidazolium-Based Ionic Liquids: Effect of the Anion. J. Chem. Eng. Data 2007, 52 (6), 22042211. Tekin, A.; Safarov, J.; Shahverdiyev, A.; Hassel, E., (p, , T) Properties of 1-butyl-3methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate at T=(298.15 to 398.15) K and pressures up to p=40 MPa. J. Mol. Liq 2007, 136 (1-2), 177-182. Gardas, R. L.; Freire, M. G.; Carvalho, P. J.; Marrucho, I. M.; Fonseca, I. M. A.; Ferreira, A. G. M.; Coutinho, J. A. P., High-Pressure Densities and Derived Thermodynamic Properties of Imidazolium-Based Ionic Liquids. J. Chem. Eng. Data 2007, 52 (1), 80-88. Valderrama, J. O.; Zarricueta, K., A simple and generalized model for predicting the density of ionic liquids. Fluid Phase Equilibr. 2009, 275, 145-151. de Castro, C. A. N.; Langa, E.; Morais, A. L.; Lopes, M. L. S. M.; Lourenco, M. J. V.; Santos, F. J. V.; Santos, M. S. C. S.; Lopes, J. N. C.; Veiga, H. I. M.; Macatrao, M.; Esperanca, J. M. S. S.; Marques, C. S.; Rebelo, L. P. N.; Afonso, C. A. M., Studies on the density, heat capacity, surface tension and infinite dilution diffusion with the ionic liquids [C4mim][NTf2], [C4mim][dca], [C2mim][EtOSO3] and [Aliquat][dca]. Fluid Phase Equilibr. 2010, 294 (1-2), 157-179. Aki, S. N. V. K.; Mellein, B. R.; Saurer, E. M.; Brennecke, J. F., High-Pressure Phase Behavior of Carbon Dioxide with Imidazolium-Based Ionic Liquids. J. Phys. Chem. B. 2004, 108 (52), 2035520365. Govinda, V.; Attri, P.; Venkatesu, P.; Venkateswarlu, P., Thermophysical properties of dimethylsulfoxide with ionic liquids at various temperatures. Fluid Phase Equilibr. 2011, 304, 3543. He, R. H.; Long, B. W.; Lu, Y. Z.; Meng, H.; Li, C. X., Solubility of Hydrogen Chloride in Three 1Alkyl-3-methylimidazolium Chloride Ionic Liquids in the Pressure Range (0 to 100) kPa and Temperature Range (298.15 to 363.15) K. J. Chem. Eng. Data 2012, 57, 2936-2941. Esperanca, J. M. S. S.; Guedes, H. J. R.; Lopes, J. N. C.; Rebelo, L. P. N., Pressure−Density−Temperature (p−ρ−T) Surface of [C6mim][NTf2]. J. Chem. Eng. Data 2008, 53, 867-870. Restolho, J.; Serro, A. P.; Mata, J. L.; Saramago, B., Viscosity and Surface Tension of 1-Ethanol-3methylimidazolium Tetrafluoroborate and 1-Methyl-3-octylimidazolium Tetrafluoroborate over a Wide Temperature Range. J. Chem. Eng. Data 2009, 54, 950-955. Muldoon, M. J.; Aki, S. N. V. K.; Anderson, J. L.; Dixon, J. K.; Brennecke, J. F., Improving carbon dioxide solubility in ionic liquids. J. Phys. Chem. B 2007, 111 (30), 9001-9009. Carrera, G. V. S. M.; Afonso, C. A. M.; Branco, L. C., Interfacial Properties, Densities, and Contact Angles of Task Specific Ionic Liquids J. Chem. Eng. Data 2010, 55, 609-615. Breneman, C. M.; Wiberg, K. B., Determining Atom-Centered Monopoles from Molecular Electrostatic Potentials - The Need for High Sampling Density in Formamide ConformationalAnalysis. J. Comput. Chem. 1990, 11 (3), 361-373.
What Determines CO2 Solubility in Ionic Liquids? A Molecular Simulation Study Marco Klähn,1* Abirami Seduraman2 1
Institute of Chemical and Engineering Science, Agency for Science, Technology and Research,
1 Pesek Road, Jurong Island, Singapore 627833 2
Institute of High Performance Computing, Agency for Science, Technology and Research, 1
Fusionopolis Way, #16-16, Connexis, Singapore 138632, Rep. of Singapore
*To whom correspondence should be addressed. Phone: (65) 67963946. E-mail: [email protected]
Table S1: Comparison of Measured and Calculated Mass Densities of ILsa
ILs
ρexp [mol/l]
ρcalce [mol/l]
BMIM-PF6a
4.811-2
4.691
BMIM-BF4a
5.331, 3
5.161
BMIM-NO3b
5.764
5.621
BMIM-NTF2a
3.435-6
3.491
BMIM-Clb
6.177-8
6.031
C6MIM-NTf2b
3.079
3.061
C8MIM-PF6a
3.643
3.491
C2OHMIM-BF4b
6.1110
5.971
C6F9MIM-NTf2c
3.5611
3.581
MOEMIM-BF4d
5.7312
5.501
a
At T = 298 K and P = 10 bar.
b
At T = 298 K and P = 1 bar.
c
Saturated with CO2 at T = 298 K and P = 11.1 bar.
d e
At T = 293 K and P = 1 bar. Statistical uncertainties of the last digit are given as subscripts.
Figure S1: Structural formulas of all considered cations (left hand side) and anions (right hand side) in simulations together with their abbreviations used in the text.
Figure S2a: Atomistic partial charges used in force fields for the ions in BMIM-PF6, BMIMBF4, BMIM-NO3, and BMIM-NTf2. The partial charges are based on the electrostatic potential of the ions (ESP charges) in the actual liquid phase of the corresponding IL, derived with the CHELPG scheme.13 Charges of chemically equivalent atoms were averaged. Partial charges are given in units of the elementary charge.
Figure S2b: Atomistic partial charges used in force fields for the ions in BMIM-Cl, C6MIMNTf2, and C8MIM-PF6. The partial charges are based on the electrostatic potential of the ions (ESP charges) in the actual liquid phase of the corresponding IL, derived with the CHELPG scheme.13 Charges of chemically equivalent atoms were averaged. Partial charges are given in units of the elementary charge.
Figure S2c: Atomistic partial charges used in force fields for the ions in C2OHMIM-BF4, C6F9MIM-NTf2, and MOEMIM-BF4. The partial charges are based on the electrostatic potential of the ions (ESP charges) in the actual liquid phase of the corresponding IL, derived with the CHELPG scheme.13 Charges of chemically equivalent atoms were averaged. Partial charges are given in units of the elementary charge.
Figure S3: Distribution of empty space in pure C2OHMIM-BF4 (top) and when saturated with CO2 (bottom) in a cross section of a sample structure of the equilibrated IL. Regions of empty space were located with XCav and are shown in orange. CO2 is displayed in green. Ions and CO2 are shown in the van der Waals representation.
Figure S4: Distribution of empty space in pure C6MIM-NTf2 (top) and when saturated with CO2 (bottom) in a cross section of a sample structure of the equilibrated IL. Regions of empty space were located with XCav and are shown in orange. CO2 is displayed in green. Ions and CO2 are shown in the van der Waals representation.
References 1.
2.
3.
4. 5.
6.
7.
8.
9.
10.
11. 12. 13.
Jacquemin, J.; Husson, P.; Mayer, V.; Cibulka, I., High-Pressure Volumetric Properties of Imidazolium-Based Ionic Liquids: Effect of the Anion. J. Chem. Eng. Data 2007, 52 (6), 22042211. Tekin, A.; Safarov, J.; Shahverdiyev, A.; Hassel, E., (p, , T) Properties of 1-butyl-3methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate at T=(298.15 to 398.15) K and pressures up to p=40 MPa. J. Mol. Liq 2007, 136 (1-2), 177-182. Gardas, R. L.; Freire, M. G.; Carvalho, P. J.; Marrucho, I. M.; Fonseca, I. M. A.; Ferreira, A. G. M.; Coutinho, J. A. P., High-Pressure Densities and Derived Thermodynamic Properties of Imidazolium-Based Ionic Liquids. J. Chem. Eng. Data 2007, 52 (1), 80-88. Valderrama, J. O.; Zarricueta, K., A simple and generalized model for predicting the density of ionic liquids. Fluid Phase Equilibr. 2009, 275, 145-151. de Castro, C. A. N.; Langa, E.; Morais, A. L.; Lopes, M. L. S. M.; Lourenco, M. J. V.; Santos, F. J. V.; Santos, M. S. C. S.; Lopes, J. N. C.; Veiga, H. I. M.; Macatrao, M.; Esperanca, J. M. S. S.; Marques, C. S.; Rebelo, L. P. N.; Afonso, C. A. M., Studies on the density, heat capacity, surface tension and infinite dilution diffusion with the ionic liquids [C4mim][NTf2], [C4mim][dca], [C2mim][EtOSO3] and [Aliquat][dca]. Fluid Phase Equilibr. 2010, 294 (1-2), 157-179. Aki, S. N. V. K.; Mellein, B. R.; Saurer, E. M.; Brennecke, J. F., High-Pressure Phase Behavior of Carbon Dioxide with Imidazolium-Based Ionic Liquids. J. Phys. Chem. B. 2004, 108 (52), 2035520365. Govinda, V.; Attri, P.; Venkatesu, P.; Venkateswarlu, P., Thermophysical properties of dimethylsulfoxide with ionic liquids at various temperatures. Fluid Phase Equilibr. 2011, 304, 3543. He, R. H.; Long, B. W.; Lu, Y. Z.; Meng, H.; Li, C. X., Solubility of Hydrogen Chloride in Three 1Alkyl-3-methylimidazolium Chloride Ionic Liquids in the Pressure Range (0 to 100) kPa and Temperature Range (298.15 to 363.15) K. J. Chem. Eng. Data 2012, 57, 2936-2941. Esperanca, J. M. S. S.; Guedes, H. J. R.; Lopes, J. N. C.; Rebelo, L. P. N., Pressure−Density−Temperature (p−ρ−T) Surface of [C6mim][NTf2]. J. Chem. Eng. Data 2008, 53, 867-870. Restolho, J.; Serro, A. P.; Mata, J. L.; Saramago, B., Viscosity and Surface Tension of 1-Ethanol-3methylimidazolium Tetrafluoroborate and 1-Methyl-3-octylimidazolium Tetrafluoroborate over a Wide Temperature Range. J. Chem. Eng. Data 2009, 54, 950-955. Muldoon, M. J.; Aki, S. N. V. K.; Anderson, J. L.; Dixon, J. K.; Brennecke, J. F., Improving carbon dioxide solubility in ionic liquids. J. Phys. Chem. B 2007, 111 (30), 9001-9009. Carrera, G. V. S. M.; Afonso, C. A. M.; Branco, L. C., Interfacial Properties, Densities, and Contact Angles of Task Specific Ionic Liquids J. Chem. Eng. Data 2010, 55, 609-615. Breneman, C. M.; Wiberg, K. B., Determining Atom-Centered Monopoles from Molecular Electrostatic Potentials - The Need for High Sampling Density in Formamide ConformationalAnalysis. J. Comput. Chem. 1990, 11 (3), 361-373.
