Deep Eutectic Solvents contains a comprehensive review of the use of deep eutectic solvents (DESs) as an environmentally benign alternative reaction media for chemical transformations and processes. The contributors cover a range of topics including synthesis, structure, properties, toxicity and biodegradability of DESs. The book also explores myriad applications in various disciplines, such as organic synthesis and (bio)catalysis, electrochemistry, extraction, analytical chemistry, polymerizations, (nano)materials preparation, biomass processing, and gas adsorption.
The book is aimed at organic chemists, catalytic chemists, pharmaceutical chemists, biochemists, electrochemists, and others involved in the design of eco-friendly reactions and processes. This important book:
-Explores the promise of DESs as an environmentally benign alternative to hazardous organic solvents
-Covers the synthesis, structure, properties (incl. toxicity) as well as a wide range of applications
-Offers a springboard for stimulating critical discussion and encouraging further advances in the field
Deep Eutectic Solvents is an interdisciplinary resource for researchers in academia and industry interested in the many uses of DESs as an environmentally benign alternative reaction media.
Table of Contents
Preface xiii
1 Synthesis and Properties 1
Karine De Oliveira Vigier and Francois Jerome
1.1 Introduction 1
1.2 Synthesis 2
1.3 Properties 4
1.3.1 Freezing Point (Tf) 4
1.3.2 Density 5
1.3.3 Viscosity 11
1.3.4 Ionic Conductivity 16
1.3.5 Polarity 19
1.3.6 Surface Tension 19
1.4 Summary and Conclusions 21
References 21
2 Structure and Implications 25
Oliver S. Hammond and Karen J. Edler
2.1 Introduction 25
2.2 Nanostructure of DES 26
2.2.1 Complex Ion Model 26
2.2.2 An Extended Hydrogen Bond Network Model: “Alphabet Soup” 27
2.2.3 Non‐cholinium DES 36
2.3 Conclusions and Implications 38
Abbreviations 40
References 40
3 Toxicity and Biodegradability of Deep Eutectic Solvents and Natural Deep Eutectic Solvents 43
Zhen Yang
3.1 Introduction 43
3.2 Toxicity to Microorganisms 44
3.2.1 Toxicity to Bacteria 44
3.2.2 Toxicity to Other Microorganisms 47
3.3 Toxicity to Animals 48
3.3.1 In Vitro Toxicity Tests on Vertebrates and Invertebrates 48
3.3.2 Cytotoxicity 49
3.3.3 In Vivo Acute Toxicity Tests and Pharmacokinetics 53
3.4 Toxicity to Plants 55
3.5 Biodegradability 56
3.6 Summary and Conclusions 57
Abbreviations 58
References 59
4 Natural Deep Eutectic Solvents: From Their Discovery to Their Applications 61
Henni Vanda, Robert Verpoorte, Peter G. L. Klinkhamer, and Young H. Choi
4.1 Introduction 61
4.2 Natural Deep Eutectic Solvents is a Concept Based on How Physicochemical Features Could Be Used for Biological Functions 63
4.3 Extraction and Solubilization of Non‐water‐Soluble Metabolites 66
4.4 Solvents for Macromolecules 69
4.4.1 Application of ILs and DES to Macromolecules 69
4.4.2 Recent NADES Application for DNA, RNA, and Proteins 70
4.5 Application to Enzyme Reactions 75
4.6 Pharmaceutical Applications 76
4.7 Perspective of NADES 76
Abbreviations 79
References 79
5 Hydrophobic Deep Eutectic Solvents 83
Samah E.E. Warrag and Maaike C. Kroon
5.1 Introduction 83
5.2 Physiochemical Properties of Hydrophobic DESs 84
5.2.1 Density 85
5.2.2 Viscosity 86
5.3 Thermal Stability Window 86
5.4 Applications of Hydrophobic DESs 87
5.4.1 The Extraction of Fatty Acids and Biomolecules from Water 87
5.4.2 The Removal of Transition Metal Ions from Water 89
5.4.3 Impregnation in Membranes 90
5.4.4 The Removal of Pesticides from Water 90
5.4.5 CO2 Capture 90
5.5 Prediction of the Hydrophobic DESs Phase Behavior 91
5.5.1 The Use of PC‐SAFT 91
5.6 Outlook and Recommendations 92
Abbreviations 92
References 93
6 Deep Eutectic Solvents: Exploring Their Role in Nature 95
Rita Craveiro, Francisca Mano, Alexandre Paiva, and Ana Rita C. Duarte
6.1 (Introduction) DES in Nature 95
6.2 Honey 97
6.2.1 Behind Beehive: How Honey is Really Produced? 98
6.2.2 Honey and Its Properties 99
6.2.3 Honey as the First THEDES 99
6.3 Maple Syrup: How is Maple Syrup Produced? 100
6.3.1 Maple Syrup Nutraceutical Value 101
6.3.2 Maple Syrup and NADES 102
6.4 Sugar Beet 102
6.5 Resurrection Plants 106
6.6 Summary and Conclusions 107
Abbreviations 107
Acknowledgments 108
References 108
7 Organic Synthesis in DESs 111
Filippo M. Perna, Paola Vitale, and Vito Capriati
7.1 Introduction 111
7.2 DESs in Organocatalysis 112
7.3 DESs in the Synthesis of Heterocycles 116
7.3.1 Synthesis of Nitrogen‐ or Nitrogen‐ and Oxygen‐Containing Rings in DESs 117
7.3.2 Synthesis of Thiophenes in DESs 119
7.3.3 Synthesis of Benzo‐Condensed Rings in DESs 120
7.4 Multicomponent Reactions in DESs 123
7.4.1 Multicomponent Reactions in the Synthesis of Heterocycles 123
7.4.2 Synthesis of Betti Bases in DESs 128
7.4.3 Ugi and Passerini Reactions 128
7.5 Miscellaneous Transformations in DESs 129
7.6 Conclusion and Perspective 130
Abbreviations 131
References 132
8 DES as Catalyst 135
Mehran Shahiri‐Haghayegh and Najmedin Azizi
8.1 Introduction 135
8.2 DES Promoted Organic Transformations 136
8.2.1 Fischer Indole Synthesis 136
8.2.2 Carbon-Carbon Bond Formation 138
8.2.3 Synthesis of Pyrroles 141
8.2.4 Oxidation Reactions 141
8.2.5 “Green” Multicomponent Reactions 142
8.2.5.1 Isocyanide‐Based MCRs 143
8.2.5.2 Mannich‐Type Reactions 144
8.2.5.3 Biginelli Reaction 147
8.2.5.4 Synthesis of Chromene, Pyran, and Spiroxindole Derivatives 149
8.2.5.5 Multicomponent Synthesis of Pyrrole and Pyrazole 149
8.2.5.6 Synthesis of Quinazoline 153
8.2.5.7 A3‐Coupling Reaction 153
8.3 Desulfurization of Fuels 154
8.3.1 Olefin Alkylation of Thiophenic Sulfur 155
8.3.2 Oxidative Desulfurization of Fuels 156
8.4 Biodiesel Production 157
8.4.1 Transesterification of Triglycerides 158
8.4.2 Esterification of Free Fatty Acids 159
8.4.3 Hydrolysis/Dehydration of Carbohydrates 160
8.5 CO2 Chemical Fixation 161
8.6 Chemical Recycling of Polymers 163
8.7 Epoxy Resin Crosslinking 165
8.8 Supramolecular Macrocyclic Host Synthesis 166
8.9 Conclusion 166
References 167
9 Metal‐Promoted Organic Transformation in DES 171
Cristian Vidal and Joaquin Garcia‐Alvarez
9.1 Introduction 171
9.2 Design of New Synthetic Sustainable Organic Procedures Coupling Deep Eutectic Solvents and Highly‐Polarized Organometallic Reagents (RLi and RMgX) 173
9.3 Transition‐Metal‐Catalyzed Organic Reactions in Deep Eutectic Solvents 177
9.3.1 Palladium Catalyzed C-C Coupling Reactions in DESs 177
9.3.2 Ruthenium Catalyzed Isomerization of Allylic Alcohols and Design of One‐Pot Tandem Reactions in DESs 179
9.3.3 Gold Catalyzed Cycloisomerizations of Unsaturated Organic Substrates in DESs 180
9.4 Summary and Conclusions 181
Abbreviations 182
Acknowledgments 182
References 183
10 Polymerizations 187
Josue D. Mota‐Morales
10.1 Introduction 187
10.2 Deep Eutectic Solvents and Green Chemistry 188
10.3 The Role of Deep Eutectic Solvents in Polymerizations 189
10.3.1 Polymerizations Carried Out in Deep Eutectic Solvents 189
10.3.2 Polymerization of Monomers Containing Deep Eutectic Solvents: DES Monomers 191
10.3.3 DES as Cosolvents and Auxiliaries in Polymerizations 192
10.3.4 Cooperative Hydrogen Bonding Network of Water Added to DESs 194
10.4 Mechanisms of Polymerization Explored 194
10.4.1 Polycondensation 194
10.4.2 Free‐Radical Polymerization 197
10.4.3 Ring Opening Polymerization 207
10.4.4 Other Mechanisms of Polymerizations 209
10.5 Outlook and Future Directions 210
Abbreviations 212
References 212
11 Extraction of Bioactive Compounds 217
Mohamad H. Zainal‐Abidin, Maan Hayyan, Gek C. Ngoh, Won F. Wong, and Adeeb Hayyan
11.1 Introduction 217
11.2 The Main Features of DESs as an Extractive Agent 218
11.2.1 Effect of Water Addition on Extraction Efficiency 219
11.3 DESs in the Bioactive Compound Extractions 221
11.3.1 Phenolic Compounds 222
11.3.1.1 Flavonoid Compounds 225
11.3.2 Polysaccharides 226
11.3.3 Proteins 227
11.3.4 Hydrophobic Compounds 228
11.4 Summary 230
Abbreviations 230
References 231
12 Processing of Biomass in Deep Eutectic Solvents 235
Miao Zuo, Xianhai Zeng, Yong Sun, Xing Tang, and Lu Lin
12.1 Introduction 235
12.2 Chemical Process of Products Extraction from Biomass in DESs 235
12.2.1 Extraction and Solubility of Lignocellulose in DESs 235
12.2.2 Value‐Added Products Extraction from Biomass in DESs 238
12.3 Modification of Cellulose in DESs 240
12.4 Catalytic Conversion of Carbohydrates in DESs 242
12.4.1 Catalytic Conversion of Carbohydrates in Neat DESs 242
12.4.2 HMF Production from Carbohydrates in Bio‐Based DESs 244
12.4.3 Carbohydrates Dehydration in Biphasic DES/Organic Solvent Systems 246
12.4.4 Carbohydrates Dehydration to Other Value‐Added Products in DESs 249
12.5 Conclusions and Prospects 251
Abbreviations 252
Acknowledgments 252
References 253
13 Enzyme Catalysis: In DES, with DES, and in the Presence of DES 257
Pablo Dominguez de Maria, Nadia Guajardo, and Selin Kara
13.1 DESs as “Non‐Conventional Media” and “Non‐Conventional Solutions” for Biocatalysis 257
13.2 Hydrolases and Deep Eutectic Solvents 259
13.3 Oxidoreductases and Deep Eutectic Solvents 264
13.4 Other Biocatalytic Concepts in Deep Eutectic Solvents 266
13.5 Conclusions 267
Abbreviations 268
References
268
14 Nanoscale and Functional Materials 273
Diego A. Alonso, Alejandro Baeza, Rafael Chinchilla, Cecilia Gomez, and Isidro M. Pastor
14.1 Introduction 273
14.2 Nanoparticulated Materials 274
14.3 Nanofilms and Nanolayers 282
14.4 Carbonaceous Materials 283
14.5 Porous Materials 287
14.6 DNA Manipulation 290
14.7 Summary and Conclusions 291
Abbreviations 292
References 292
15 Carbon Dioxide Capture 297
Yingying Zhang, Xiaohua Lu, and Xiaoyan Ji
15.1 Introduction 297
15.2 Properties of DESs 299
15.2.1 Thermophysical Properties 299
15.2.1.1 Gas Solubility 299
15.2.1.2 Viscosity 305
15.2.1.3 Molar Heat Capacity 309
15.2.2 Kinetic Property 312
15.3 Screening and Evaluation of DESs for CO2 Separation 313
15.3.1 Property‐Based Method 313
15.3.2 Thermodynamic Analysis‐Based Method 313
15.3.3 Process Simulation‐Based Method 314
15.4 Further Conversion with DESs 314
15.5 Conclusions 314
Abbreviations 315
References 316
16 DES‐Mediated Approaches Toward Green Analytical Chemistry 321
Federico J.V. Gomez, Magdalena Espino, Maria de los A. Fernandez, Joana Boiteux, and Maria F. Silva
16.1 Introduction 321
16.2 Extraction Techniques and Deep Eutectic Solvents 323
16.2.1 Ultrasound Assisted Extraction (UAE) 324
16.2.2 Microwave Assisted Extraction (MAE) 325
16.2.3 Liquid Phase Microextraction (LPME) 325
16.2.4 Solid Phase Microextraction (SPME) 326
16.3 Separation Techniques and DES 326
16.3.1 Gas Chromatography and DES 327
16.3.2 Liquid Chromatography and DES 327
16.3.3 Capillary Electrophoresis and DES 328
16.4 DES Detection Techniques Compatibility 328
16.5 Future Trends and Challenges for Green Solvents in Analytical Chemistry 330
Abbreviations 331
Acknowledgments 332
References 332
17 Electrochemistry 335
Zhimin Xue, Wancheng Zhao, and Tiancheng Mu
17.1 Introduction 335
17.2 Conductivity 336
17.3 Electrochemical Stability 347
17.4 Electrochemical Applications 350
17.4.1 Electrodeposition 350
17.4.2 Electropolishing 357
17.5 Summary and Conclusions 359
Abbreviations 359
Acknowledgments 360
References 360
Index 363
