Characterization of Ionic Liquid Solvents using a Temperature Independent, Ion-Specific Abraham ...

859 Pages·2014·19.6 MB·English

by  Stephens, Timothy W.

CHARACTERIZATION OF IONIC LIQUID SOLVENTS USING A TEMPERATURE INDEPENDENT,

ION-SPECIFIC ABRAHAM PARAMETER MODEL

Timothy W. Stephens, B. A.

Dissertation Prepared for the Degree of

DOCTOR OF P HILOSOPHY

UNIVERSITY OF NORTH TEXAS

December 2014

APPROVED:

William E. Acree, Jr., Major Professor and Chair
of the Department of Chemistry
Teresa Golden, Committee Member
Martin Schwartz, Committee Member
Ruthanne D. Thomas, Committee Member
Mark Wardell, Dean of the Toulouse Graduate
School
Stephens, Timothy W. Characterization of Ionic Liquid Solvents using a Temperature
Independent, Ion-Specific Abraham Parameter Model. Doctor of Philosophy (Chemistry –
Analytical Chemistry), December 2014, 846 pp., 71 tables, 7 figures, chapter references.
Experimental data for the logarithm of the gas-to-ionic liquid partition coefficient (log K)
have been compiled from the published literature for over 40 ionic liquids over a wide
temperature range. Temperature independent correlations based on the Gibbs free energy
equation utilizing known Abraham solvation model parameters have been derived for the
prediction of log K for 12 ionic liquids to within a standard deviation of 0.114 log units over a
temperature range of over 60 K. Temperature independent log K correlations have also been
derived from correlations of molar enthalpies of solvation and molar entropies of solvation, each
within standard deviations of 4.044 kJ mol-1 and 5.338 J mol-1 K-1, respectively. In addition, molar
enthalpies of solvation and molar entropies of solvation can be predicted from the Abraham
coefficients in the temperature independent log K correlations to within similar standard
deviations. Temperature independent, ion specific coefficients have been determined for 26
cations and 15 anions for the prediction of log K over a temperature range of at least 60 K to
within a standard deviation of 0.159 log units.
Copyright 2014
by
Timothy W. Stephens

ii
ACKNOWLEDGMENTS
I would like to thank the University of North Texas Department of Chemistry for the
guidance and support during my journey in completing this dissertation. I will forever be
grateful to Dr. William Acree for everything he has done. Dr. Acree has been an invaluable
wealth of information and has helped me stay focused and on-track with my research. I also
need to thank Drs. Teresa Golden, Martin Schwartz, and Ruthanne Thomas for their many
valued pieces of advice and guidance. Additionally, I would like to thank Dr. Diana Mason for
introducing me to Dr. Acree and getting me started on this journey. Lastly, I would like to thank
Ms. Susan Brockington for helping me navigate all of the intricacies of my graduate student
career.
Much of the research presented in this dissertation would not have been possible
without the contributions of Dr. Jared Anderson and Mr. Fabrice Mutelet. I would like to thank
both of these men for generously sharing their data for use in this dissertation. I also need to
thank all of the undergraduate students and TAMS students that have been a part of the Acree
Research Group for help in analyzing the data presented in this dissertation.
Last, and certainly not least, this dissertation would not have been possible without the
support and encouragement of my family and friends. There are not enough words to thank
Anna George, Robyn Ford, Jim Marshall, or Leroy Theriot for keeping me sane while working on
this dissertation. Everything I have done is in dedication to my parents Doug and Lorene
Stephens, as well as my little sister Tammy. If not for your constant pushing and forcing me to
do better, I never would have made it this far. Thank you everyone for putting up with me and
bearing with me during everything.
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TABLE OF CONTENTS
ACKNOWLEDGMENTS ................................................................................................................III
LIST OF TABLES ........................................................................................................................ VIII
LIST OF FIGURES ........................................................................................................................XII
CHAPTER 1 THE ABRAHAM SOLVATION MODEL AND ITS APPLICATIONS .....................................1
Solute Descriptors and Process Coefficients ............................................................................2
and ................................................................................................................................2
𝑬 𝑒
and ................................................................................................................................3
𝑺 𝑠
and ...............................................................................................................................4
𝑨 𝑎
and ...............................................................................................................................5
𝑩 𝑏
and .................................................................................................................................5
𝑳 𝑙
and ...............................................................................................................................6
𝑽 𝑣
Applications of the Abraham model ........................................................................................7
Solute Partitioning ...............................................................................................................7
Enthalpy of Solvation ...........................................................................................................9
Ionic Liquids ......................................................................................................................31
Other Applications of the Abraham model ........................................................................31
References ............................................................................................................................33
CHAPTER 2 COMPUTATIONAL METHODS AND DATA TRANSFORMATION..................................42
iv
Data Collection and Transformation ......................................................................................42
Multiple Linear Regression ....................................................................................................43
Validation of Regression ........................................................................................................46
References ............................................................................................................................46
CHAPTER 3 DETERMINATION OF TEMPERATURE INDEPENDENT CORRELATIONS FOR THE
PREDICTION OF THE LOGARITHM OF THE GAS-TO-SOLVENT COEFFICIENT FOR VARIOUS IONIC
LIQUIDS .....................................................................................................................................48
Introduction ..........................................................................................................................48
Computational Methods and Data Analysis ...........................................................................50
Results and Discussion ..........................................................................................................52
Conclusions and Future Work ................................................................................................59
References ............................................................................................................................60
CHAPTER 4 DETERMINATION OF ENTHALPIES OF SOLVATION FOR VARIOUS IONIC LIQUID
SOLVENTS .................................................................................................................................62
Introduction ..........................................................................................................................62
Computational Methods and Data Analysis ...........................................................................64
Results and Discussion ..........................................................................................................65
Conclusions and Future Work ................................................................................................70
References ............................................................................................................................71
v
CHAPTER 5 DETERMINATION OF ENTROPIES OF SOLVATION FOR VARIOUS IONIC LIQUID
SOLVENTS .................................................................................................................................73
Introduction ..........................................................................................................................73
Computational Methods and Data Analysis ...........................................................................75
Results and Discussion ..........................................................................................................79
Conclusions and Future Work ................................................................................................80
References ............................................................................................................................81
CHAPTER 6 A DIFFERENT METHOD FOR DERIVING TEMPERATURE INDEPENDENT CORRELATIONS
FOR THE PREDICITON OF THE LOGARITHM OF THE GAS-TO-SOLVENT COEFFICIENT FOR
VARIOUS IONIC LIQUIDS ............................................................................................................82
Introduction ..........................................................................................................................82
Computational Methods and Data Analysis ...........................................................................83
Results and Discussion ..........................................................................................................83
Conclusions ...........................................................................................................................87
References ............................................................................................................................88
CHAPTER 7 DETERMINATION OF TEMPERATURE INDEPENDENT, ION-SPECIFIC SOLVENT
COEFFICIENTS FOR USE IN THE ABRAHAM SOLVATION MODEL .................................................89
Introduction ..........................................................................................................................89
Computational Methods and Data Analysis ...........................................................................91
Results and Discussion ..........................................................................................................93
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Conclusions and Future Work .............................................................................................. 101
References .......................................................................................................................... 102
CHAPTER 8 DETERMINATION OF SOLVENT COEFFICIENTS THROUGH THE USE OF A
TEMPERATURE INDEPENDENT, GROUP CONTRIBUTION METHOD FOR IONIC LIQUIDS ............ 109
Introduction ........................................................................................................................ 109
Computational Methods and Data Analysis ......................................................................... 113
Results and Discussion ........................................................................................................ 113
Conclusions and Future Work .............................................................................................. 123
References .......................................................................................................................... 123
CHAPTER 9 CONCLUSIONS....................................................................................................... 125
References .......................................................................................................................... 127
APPENDIX A ABBREVIATIONS OF COMPOUNDS USED IN CHAPTER 1 ....................................... 128
APPENDIX B SUPPLEMENTAL INFORMATION FOR CHAPTERS 3 AND 6 ..................................... 133
APPENDIX C SUPPLEMENTAL INFORMATION FOR CHAPTER 4 ................................................. 305
APPENDIX D SUPPLEMENTAL INFORMATION FOR CHAPTER 5 ................................................. 338
APPENDIX E SUPPLEMENTAL INFORMATION FOR CHAPTERS 7 AND 8 ..................................... 490

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LIST OF TABLES
Table 1.1: Values for Non-metal Atoms .................................................................................6
𝑉𝑎
Table 1.2: Abraham Model Coefficients ............................................................................10
log𝐾
Table 1.3: Abraham Model Coefficients ............................................................................22
log𝑃
Table 1.4: Abraham Model Coefficients .......................................................................29
∆𝐻𝑠𝐻𝑙𝑣
Table 1.5: Abraham Model Coefficients for Toxicity Predictions in Various Organisms ..............32
Table 3.1: List of Ionic Liquids and Abbreviations ......................................................................51
Table 3.2: Proportionality Constants .........................................................................................52
Table 3.3: Temperature Independent Coefficients ....................................................................53
Table 4.1: List of Ionic Liquids and Abbreviations ......................................................................64
Table 4.2: Experimental Molar Enthalpy of Solvation Coefficients for Various Ionic Liquids .......66
Table 4.3: Molar Enthalpy of Solvation Coefficients from Temperature Independent
log𝐾
Correlations ..............................................................................................................................67
Table 5.1: Calculated Process Coefficients for the Prediction of for Various Ionic Liquids
∆𝑆𝑠𝐻𝑙𝑣
.................................................................................................................................................76
Table 5.2: Predicted Process Coefficients for the Prediction of Based on Values from
log𝐾
Tables 4.1 and 5.1 .....................................................................................................................77
Table 6.1: Partial Copy of Table 3.3 ...........................................................................................84
Table 6.2: Temperature Independent Coefficients Based on Eqn. 6.2 ........................................85
Table 7.1: Matrix Before Calculations ........................................................................................92
Table 7.2: Matrix After Calculations ..........................................................................................92
Table 7.3: List of Ion Names and Abbreviations Used in this Study. ...........................................95
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Table 7.4: Cation-Specific Coefficients .......................................................................................97
Table 7.5: Anion-Specific Coefficients ........................................................................................99
Table 7.6: Predicted Coefficients to Determine ............................................................... 100
log𝐾
Table 8.1: Functional Groups as Defined by Mutelet et al. [1]. ................................................ 110
Table 8.2: Updated Functional Groups .................................................................................... 111
Table 8.3: Calculated Group Coefficients Based on the Functional Groups Listed in Table 8.1 . 114
Table 8.4: Calculated Group Coefficients Based on the Functional Groups Listed in Table 9.2 . 116
Table 8.5: Predicted Temperature Independent Coefficients Based on the Values in Table
log𝐾
8.3 ........................................................................................................................................... 121
Table 8.6: Predicted Temperature Independent Coefficients Based on the Values in Table
log𝐾
8.4 ........................................................................................................................................... 121
Table A.1: List of Abbreviations and Full Names of Compounds listed in Table 1.2 and Table 1.3
............................................................................................................................................... 129
Table B.1: Data for [MEIm]+[N(CN) ]- .............................................................................. 134
2
Table B.2: log𝐾 Data for [HiQuin]+[SCN]- ................................................................................. 145
Table B.3: log𝐾 Data for [HMPip]+[Tf N]- ................................................................................. 156
2
Table B.4: log𝐾 Data for [MeoeMMorp]+[FAP]- ....................................................................... 165
Table B.5: log𝐾 Data for [MeoeMMorp]+[Tf N]- ...................................................................... 191
2
Table B.6: log𝐾 Data for [MeoeMPip]+[FAP]- ........................................................................... 204
Table B.7: log𝐾 Data for [MeoeMPip]+[Tf N]- .......................................................................... 224
2
Table B.8: log𝐾 Data for [MeoeMPyrr]+[FAP]- ......................................................................... 237
Table B.9: log𝐾 Data for [MeoeMPyrr]+[Tf N]- ........................................................................ 260
2
log𝐾
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