Ionic Liquids

Home , Ionic liquid

Vol. 5 No. 6

Enabling Technologies Ionic Liquids

BASIL™

BASIONICS™

Ionic Liquids for Catalysis

Ionic Liquids for Electrochemical Applications

Enzymatic Reactions in Ionic Liquids

Task-Specific Ionic Liquids

CYPHOS® Phosphonium Ionic Liquids

Imidazolium-Based Ionic Liquids

Pyridinium-Based Ionic Liquids

Pyrrolidinium-Based Ionic Liquids

Ammonium-Based Ionic Liquids

Phosphonium-Based Ionic Liquids

sigma-aldrich.com/chemicalsynthesis 2

Introduction

Sigma-Aldrich is proud to offer a new series of ChemFiles—called The strong ionic (Coulomb-) interaction within these substances results Enabling Technologies—to our Chemistry customers. Each piece will in a negligible vapor pressure (unless decomposition occurs), a non- highlight enabling products or technologies for chemical synthesis, drug flammable substance, and in a high thermally, mechanically as well discovery, and other areas of chemistry. as electrochemically stable product. In addition to this very interesting Ionic Liquids have experienced a comet-like boost in the last few years. combination of properties, they offer other favorable properties: for In this edition of ChemFiles, we highlight some current applications example, very appealing solvent properties and immiscibility with water of this fascinating class of new materials. We present over 50 new or organic solvents that result in biphasic systems. additions to our portfolio of 130+ Ionic Liquids, ranging from well- The choice of the cation has a strong impact on the properties of known imidazolium and pyridinium derivatives to ammonium, the Ionic Liquid and will often define the stability. The chemistry and pyrrolidinium, phosphonium, and sulfonium derivatives. At Sigma- functionality of the Ionic Liquid is, in general, controlled by the choice Aldrich, we are committed to being your preferred supplier for Ionic of the anion. The combination of a broad variety of cations and Liquids. Please visit sigma-aldrich.com/ionicliquids for a regular anions leads to a theoretically possible number of 1018 Ionic Liquids. update of the latest Ionic Liquids. If you cannot find a product for your However, a realistic number will be magnitudes lower. Today about specific research, “please bother us” at [email protected] 1000 Ionic Liquids are described in the literature, and approximately with new suggestions! 300 are commercially available. Typical structures combine organic cations with inorganic or organic anions:

R2 R4 N R N 1 R3 Introduction N N R2 R1 R2 R1

imidazolium pyridinium pyrrolidinium

cation R4 R4 (organic) R1 R1 P R4 R N R 1 4 S R R R2 R2 2 3

phosphonium ammonium sulfonium

O O O Ionic Liquids are a new class of purely ionic, salt-like materials that are R O S O H3C S O R3CS O liquid at unusually low temperatures. Currently, the “official” definition O O O of Ionic Liquids uses the boiling point of water as a point of reference: alkylsulfate tosylate methanesulfonate anion “Ionic Liquids are ionic compounds which are liquid below 100 °C.” (organic) More commonly, Ionic Liquids have melting points below room temperature; some of them even have melting points below 0 °C. O O N anion These new materials are liquid over a wide temperature range (300– S S PF6 BF4 Hal (inorganic) F C CF 400 °C) from the melting point to the decomposition temperature of 3 O O 3 the Ionic Liquid. If we compare a typical Ionic Liquid, e.g., 1-ethyl-3-methylimidazolium bis(trifluoromethyl- hexafluoro- tetrafluoro- halide sulfonyl)imide phosphate borate ethylsulfate (m.p. <-20 °C), with a typical inorganic salt, e.g., table salt (NaCl, m.p. 801 °C), it becomes obvious why there is a difference. The Ionic Liquid has a significantly lower symmetry! Furthermore, the The growing academic and industrial interest in Ionic Liquid charge of the cation as well as the charge of the anion is distributed technology is represented by the yearly increase in the number of over a larger volume of the molecule by resonance. As a consequence, publications (source Sci-Finder™): starting from far below 100 in 1990 the solidification of the Ionic Liquid will take place at lower to more than 1500 papers published last year. temperatures. In some cases, especially if long aliphatic side chains are involved, a glass transition is observed instead of a melting point. Publications per year anion, 1600 anion, large symmetric, 1400 large 1200 1000 cation, cation, symmetric, large, 800 small unsymmetric 600

No. of papers 400 200 0 1990 1992 1994 1996 1998 2000 2002 2004 Year

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 3

Use and Applications References The reason for the increase in number of publications can be 1. Lubricants: Wang, H.; Lu, Q.; Ye, C.; Liu, W.; Cui, Z. Wear 2004, attributed to the unique properties of these new materials. Ultimately, 256, 44–48. the possible combinations of organic cations and anions places Artificial Muscles: Potential application, personal note. chemists in the position to design and fine-tune physical and chemical properties by introducing or combining structural motifs and, thereby, MALDI-TOF-Matrices: Armstrong, D. W.; Zhang, L. K.; He, L.; making tailor-made materials and solutions possible. The following Gross, M. L. Anal. Chem. 2001, 73, 3679–3686. chart summarizes important properties of Ionic Liquids and their GC-Head-Space-Solvents: Andre, M.; Loidl, J.; Schottenberger, 1 potential and current applications: H.; Bentivoglio, G.; Wurst, K.; Ongania, K.-H. Anal. Chem. 2005,

LUBRICANTS & ADDITIVES 77, 702–705. • lubricants • fuel additives Protein-Crystallization: Ionic Liquids Technologies, Patent pending. SEPARATION • gas seperations Bio-Catalysis: Moriguchi, T.; Yanagi, T.; Kunimori, M. J. Org. ELECTROELASTIC • extractive distillation MATERIALS Chem. 2000, 65, 8229–8238. • extraction • artificial muscles • membranes Hayakawa, Y.; Kawai, R. Hirata, A. J. Am. Chem Soc. 2001, 123, • robotics IONIC LIQUIDS 8165–8176. Eckstein, M.; Filho, M. V.; Liese, A.; Kragl, U. Chem. Comm. 2004, • thermal stability ELECTROLYTES • low vapor pressure 1084–1085. • fuel cells • electric conductivity ANALYTICS Liu, Y.; Wang, M.; Li, J.; Li, Z.; He, P; Liu, H.; Li, J. Chem. Comm. • sensors • interesting solvent properties • MALDI-TOF-matrices • biphasic systems possible • batteries • GC-head-space-solvents 2005, 1778–1780. • supercaps • liquid crystalline structures • protein-crystallization • metal finishing • high electroelasticity Organic Synthesis & Catalysis: For a general overview see: • coating • high heat capacity • non flammability Wasserscheid, P.; Welton, T. Ionic Liquids in Synthsis; Wiley-VCH: Weinheim, 2003. Introduction

SOLVENTS Deep Desulfuration: Bösmann, A.; Datsevich, L.; Jess, A.; Lauter, HEAT STORAGE • thermal fluids • bio-catalysis A.; Schmitz, C.; Wasserscheid, P. Chem. Comm. 2001, 2494–2495 • organic reactions & catalysis Nakashima, K.; Kubota, F.; Maruyama, T.; Goto, M. Chem. Mater. LIQUID CRYSTALS • Nano-particle-synthesis • displays • polymerization 2003, 15, 1825–1829. © IOLITEC 2005. Nano-Particle-Synthesis: Zhou, Y.; Antonietti, M. J. Am. Chem. Soc. 2003, 125, 14960–14961; Chem. Mater. 2004, 16, 544–550. The corresponding applications of Ionic Liquids can be divided in Liquid Crystals: Holbrey, J. D.; Seddon, K. R. J. Chem. Soc., their use as process chemicals and performance chemicals. In 1948, Dalton Trans. 1999, 2133–2139. this class of electrically conducting materials (1-butylpyridinium Haristoy, D.; Tsiourvas, D. Chem. Mater. 2003, 15, 2079–2083. chloride/AlCl3) first drew attention for their use as electrolytes for electrodeposition of aluminium.2 This field is still the subject of current Thermal Fluids: Wu, B.; Reddy, R. G.; Rogers, R. D. Proceedings research efforts. Other important applications in this context are their of Solar Forum, 2001. use as electrolytes for batteries and fuel cells. See also: Ionic Liquids Technologies GmbH & Co. KG, http://www.iolitec.de. The major breakthrough came with the advent of less corrosive, air-stable materials in 1992. Wilkes and Zaworotko introduced Fuel Cells: Yanes, E. G.; Gratz, S. R.; Baldwin, M. J.; Anal. Chem. 1-ethyl-3-methylimidazolium tetrafluoroborate and focused on 2001, 73, 3838–3844. 3 solvent applications. Although 1-butyl-3-methylimidazolium Sensors: See also: http://www.iolitec.de. hexafluorophosphate and -tetrafluoroborate still dominate the current literature, there are better choices with respect to Supercaps: Sato, T; Masuda, G; Takagi, K. Electrochim. Acta performance and handling. It was demonstrated in aqueous media 2004, 49, 3603–3611. the hexafluorophosphate anion and the tetrafluoroborate anion Metal Finishing: Zell, C. A.; Freyland, W. Langmuir 2003, 19, will degrade, resulting in the formation of HF, a noxious and 7445–7450. aggressive acid. Scheeren, C. W.; Machado, G.; Dupont, J.; Fichtner, P.F.P.; Texeira, Over the past five years, other interesting applications were S.R. Inorg. Chem. 2003, 42, 4738–4742. suggested, derived from the unique combination of physical Huang, J.-F.; Sun, I.-W. J. Chromat. A, 2003, 1007, 39–45. properties. For example, the use of Ionic Liquids as thermal fluids Gas Separations: Scovazzo, P; Kieft, J.; Finan, D. A.; Koval, C.; combines their heat capacity with thermal stability and a negligible DuBios, D.; Noble, R. J. Membr. Sci. 2004, 238, 57–63. vapor pressure. It is quite feasible to expect that many more applications will be brought forward by potential users and some of Extractive Distillation: Jork, C.; Seiler, M.; Beste, Y.-A.; Arlt, W. them will be realized in the next couple of years. In order to enable J. Chem. Eng. Data 2004, 49, 852–857. potential users to make use of Ionic Liquids, it will be necessary to Extraction: Uerdingen, M.; Chem. unserer Zeit 2004, 38, 212–213. give technological support and to make a range of Ionic Liquids Membranes: Branco, L. C.; Crespo, J. G.; Afonso, C. A. M. available for testing. This support also includes the development of Angew. Chem. 2002, 104, 2895–2897. toxicological data and government required notification as well as the Fortunato, R.; Afonso, C. A. M.; Reis, M. A. M.; Crespo, J. G. J. implementation of recycling concepts for the Ionic Liquid. Membr. Sci. 2004, 242, 197–209. 2. Hurley, F. H. U.S. Patent 2,446,331, 1948. Wier, T. P.; Hurley, F. S. U.S. Patent 2,446,349, 1948. Wier, T. P. U.S. Patent 2,446,350, 1948. 3. Wilkes, J. S.; Zaworotko, M. J. Chem. Comm. 1992, 965–967.

Ready to scale up? For competitive quotes on larger quantities or custom synthesis, ™ contact SAFC at 1-800-244-1173 (USA), or visit www.safcglobal.com. Order: 1.800.325.3010 Technical Service: 1.800.231.8327 4

BASIL™—BASF’s Processes Based on Ionic Liquids

Dr. Matthias Maase, Dr. Klemens Massonne, Dr. Uwe Vagt, BASF After the reaction, there are two clear liquid phases that can easily Aktiengesellschaft, 67056 Ludwigshafen, Germany, www.basf.de/new- be worked up by a simple phase separation. The upper phase is the intermediates. pure product and no reaction solvent is needed. The lower phase is Currently, the most important application of Ionic Liquids described the pure Ionic Liquid and can be deprotonated with sodium hydroxide, is their use as reaction media for chemical processes. A major regenerating the methylimidazole. breakthrough was reached with BASF’s introduction of the first ™ application on a commercial scale: the BASIL -process, which received R R N N the “Innovation for Growth Award 2004” of ECN. P + EtOH + P + R Cl R OEt NH Many chemical processes produce acids as by-products—most N Cl commonly hydrochloric acid (HCl). In those cases where the reaction Ionic Liquid product has to be protected from decomposition or other side reactions, the acid needs to be scavenged. Usually, tertiary amines such as triethylamine are added to the reaction mixture, generating an 1-Methylimidazole was doing a wonderful job in scavenging the acid, ™ ammonium salt. In many cases, this ammonium salt can be removed via but in the very first lab trials another exciting observation was made. an aqueous extraction phase. In the case of reaction mixtures that are The Ionic Liquid functioned as a nucleophilic catalyst. The combined sensitive to water, the situation is more complicated. The generation of effect is a tremendous increase in the yield per unit volume time from 8 to 690,000 kg m-3h-1. This enabled BASF to carry out the reaction, ammonium salts leads to the formation of a slurry during the reaction. 3 The slurry formation results in a number of disadvantages: highly which previously needed a 20 m batch vessel, in a little jet reactor the viscous solutions, limited heat transfer, and the ammonium salt has to size of a thumb. This little reactor is part of a continuously operated plant with a capacity of more than 1000 t/a. The plant went on stream /BASIONICS be separated by filtration.

™ in Q3/2004 at BASF’s Ludwigshafen site. This was exactly the situation BASF faced in the production of ™ diethoxyphenylphosphine, a photoinitiator intermediate prepared This BASIL -technology for scavenging acids has been applied for by reaction of dichlorophenylphosphine with ethanol. HCl had to esterifications, acylations, silylations, phosphorylations, sulfurylations, BASIL be removed from the reaction mixture or the product would have eliminations, deprotonations, and acid removals in general in lab undergone an unwanted side reaction. An aqueous extraction phase trials. BASF, having gained experience with this process from lab to would have led to hydrolysis of the desired product and therefore commercial scale up today, is in a position to offer this process for the reaction had to be carried out in a non-aqueous medium in the licensing to others with a full package of services. presence of equimolar quantities of triethylamine. The resulting mixture An additional process already developed in pilot plant scale at was a thick, nearly non-stirrable slurry. While attempting to improve this BASF is the chlorination of alcohols with HCl in the presence of unfavorable process, the idea came up: “If an acid has to be scavenged methylimidazolium chloride. The chlorination reaction is normally with a base, the formation of a salt cannot be avoided; but why not carried out with the use of phosgene or thionyl chloride as chlorinating form a liquid salt, an Ionic Liquid?” agents. In the presence of the Ionic Liquid, the Cl- is apparently a much Instead of triethylamine, 1-methylimidazole was used as an acid stronger nucleophile and, therefore, makes it possible to carry out the scavenger and immediately led to excellent results. The Ionic chlorinations in an easier and more cost-efficient method. Liquid formed in the reaction was methylimidazolium chloride. Ionic Liquids also show advantages in separation processes, such as Methylimidazolium chloride has a melting point of 75 °C and, azeotropic or extractive distillations. In separation processes, they are therefore, is a liquid at the reaction temperature of approx. 80 °C. used as entrainers or as solvent for the extraction of phenols.

BASIONICS™—BASF’s Portfolio of Ionic Liquids

Under the trade name BASIONICS™, BASF offers a portfolio of Ionic process or an application, the set of specification parameters (purity, by- Liquids—mainly based on imidazolium cations. The BASIONICS™ products, halogen content, color, viscosity, etc.) will be defined in detail. portfolio opens up a broad range of basic properties of Ionic Liquids Based on these specifications, the process for the commercial-scale and is classified into standard, acidic, basic, liquid at RT and low viscosity production is designed. products and opens up a wide range of possible applications. All of these ™ ™ It is important to note that the BASIONICS portfolio of Ionic Liquids is products are provided by Sigma-Aldrich on kg scale. The BASIONICS a living portfolio! It will be extended, but even more importantly, driven portfolio is available from BASF in 100 kg or ton scale with the same by customer requests. This is true for the cation as well as for the specification as offered by Sigma-Aldrich on sufficient notice. anion. Both parts of the molecule can be designed to the requirements Another important part of BASF’s concept in bringing Ionic Liquids in of the specific application the customer demands. With the given commercial quantities to the market is the definition of product quality. technological expertise in chemical processing as well as existing value It is apparent that for any application the right set of specification chains and raw materials from the “Verbund”, BASF is in a position parameters needs to be defined. For example, an Ionic Liquid that is to make a broad portfolio of Ionic Liquids available in commercial used for dye-sensitized solar-cells has to be colorless, but if the same quantities and at reasonable prices. Ionic Liquid is used as a non-aqueous electrolyte in a galvanic process, the color has no relevance. In the non-aqueous electrolyte example, Application Examples another parameter may have to be clearly defined. Hence, BASF As described above, there are numerous publications on Ionic Liquids. works with the following concept: once a customer (either alone or The following are examples that present some applications where in cooperation with BASF) has identified an Ionic Liquid suitable for a BASIONIC™ Ionic Liquids could be used.

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 5

Prod. # Name Applications

30764 1-Ethyl-3-methylimidazolium chloride (BASIONIC™ ST 80) precursors for the preparation of other Ionic Liquids by 38899 1-Butyl-3-methylimidazolium chloride (BASIONIC™ ST 70) anion metathesis

29164 1-Ethyl-3-methylimidazolium methanesulfonate (BASIONIC™ ST 35) electrodeposition of metals, e.g., titanium-aluminum 30881 1-Butyl-3-methylimidazolium methanesulfonate (BASIONIC™ ST 78) or platinum-zinc alloys;1–3 esterification of starch;4 dissolution and delignification of lignocellulosic materials;5 dissolution of silk fibroin6

38938 Methyl-tributylammonium methylsulfate (BASIONIC™ ST 62) electrochemical synthesis of organic compounds7

50365 1,2,3-Trimethylimidazolium methylsulfate (BASIONIC™ ST 99) production of organopolysiloxanes8

40477 Methylimidazolium chloride (BASIONIC™ AC 75) separation of acids from chemical reaction mixtures;9 ™ halogenating agent and recyclable catalyst;10 electroplating bath for Tungsten11 and Molybdenum12

59760 Methylimidazolium hydrogensulfate (BASIONIC™ AC 39) extraction medium for removing impurities from 56486 1-Ethyl-3-methylimidazolium hydrogensulfate (BASIONIC™ AC 25) aprotic solvents;13 synthesis of coumarins;14 solvent 57457 1-Butyl-3-methylimidazolium hydrogensulfate (BASIONIC™ AC 28) for GC-headspace;15 solvent and catalyst for Mannich- reaction,16 Friedel–Crafts-alkylations,17 and aromatic BASIONICS sulfonation18

51059 1-Ethyl-3-methylimidazolium tetrachloroaluminate (BASIONIC™ AC 09) electrolyte for batteries;19 synthesis of polyisoolefins;20 55292 1-Butyl-3-methylimidazolium tetrachloroaluminate (BASIONIC™ AC 01) reaction medium for Rh-catalyzed hydrogenations21 and Diels–Alder-reactions;22 extractive desulfuration of hydrocarbon fuels;23 reaction medium for synthesis and catalysis;24–26 polymerization of ethylene carbonate27

51053 1-Ethyl-3-methylimidazolium acetate (BASIONIC™ BC 01) electrolytes for non-aqueous capillary electrophoresis28 39952 1-Butyl-3-methylimidazolium acetate (BASIONIC™ BC 02)

51682 1-Ethyl-3-methylimidazolium ethylsulfate (BASIONIC™ LQ 01) extractive deep desulfuration;29 extraction of 53177 1-Butyl-3-methylimidazolium methylsulfate (BASIONIC™ LQ 02) contaminant gases;30 lipase-catalyzed enantioselective acylation31

43437 1-Ethyl-3-methylimidazolium thiocyanate (BASIONIC™ VS 01) electrolyte for dye-sensitized solar cells;32 electrolyte for 42254 1-Butyl-3-methylimidazolium thiocyanate (BASIONIC™ VS 02) dye-sensitized semiconductor-particles;33 solvent for the dissolution of cellulose with Ionic Liquids34

05338 1-Ethyl-2,3-dimethylimidazolium ethyl sulfate (BASIONIC™ ST 67)

1-Butyl-3-methylimidazolium acetate, 8 1-Butyl-3-methylimidazolium hydrogen sulfate, 8 BASF quality, ≥95% BASF quality, ≥95%

C10H18N2O2 CH3 C8H16N2O4S CH3 + N N+ FW: 198.26 O FW: 236.29 HO mp: <-20 °C N - mp: 28 °C N O OCH3 S [284049-75-8] [262297-13-2] O O-

CH3 H3C

39952-100G 100 g 198.00 57457-100G 100 g 99.00 39952-1KG 1 kg 546.50 57457-1KG 1 kg 273.20

1-Butyl-3-methylimidazolium chloride, 8 1-Butyl-3-methylimidazolium methanesulfonate, 8 BASF quality, ≥95% BASF quality, ≥95%

CH C8H15ClN2 CH3 C9H18N2O3S 3 N+ N+ FW: 174.67 Cl- FW: 234.32 H C N 3 O mp: 41 °C N mp: 75–80 °C S [79917-90-1] [342789-81-5] O O-

H3C H3C

38899-100G 100 g 79.20 30881-100G 100 g 99.00 38899-1KG 1 kg 218.60 30881-1KG 1 kg 273.20

1-Butyl-3-methylimidazolium methyl sulfate, 8 1-Ethyl-3-methylimidazolium ethyl sulfate, 8 BASF quality, ≥95% BASF quality, ≥95%

CH3 CH3 C9H18N2O4S C8H16N2O4S + H C FW: 250.32 N FW: 236.29 N+ 3 H CO N 3 O N O mp: <-20 °C S mp: <-20 °C O O - S O O - [401788-98-5] [342573-75-5] H3C O

H3C 53177-100G 100 g 79.20 51682-100G 100 g 79.20 53177-1KG 1 kg 218.60 51682-1KG 1 kg 218.60 1-Ethyl-3-methylimidazolium hydrogen sulfate, 1-Butyl-3-methylimidazolium tetrachloroaluminate, 8 8 BASF quality, ≥95% BASF quality, ≥95% CH3 CH3 C6H12N2O4S C8H15AlCl4N2 N+ + HO N – FW: 208.24 O FW: 308.01 AlCl4 N S [412009-61-1] O - mp: -10 °C N O

™ H C [80432-09-3] 3

H3C 56486-100G 100 g 118.80 55292-100G 100 g 99.00 56486-1KG 1 kg 327.90 55292-1KG 1 kg 273.20 1-Ethyl-3-methylimidazolium methanesulfonate, 8 1-Butyl-3-methylimidazolium thiocyanate, 8 BASIONICS BASF quality, ≥95% BASF quality, ≥95% CH3 C7H14N2O3S CH + C9H15N3S 3 N FW: 206.26 H3C N+ O N S FW: 197.30 – mp: 35 °C O SCN O- N mp: <-20 °C [145022-45-3] H3C [344790-87-0] H3C 29164-100G 100 g 118.80 42254-100G 100 g 158.40 29164-1KG 1 kg 327.90 42254-1KG 1 kg 437.10 1-Ethyl-3-methylimidazolium tetrachloroaluminate, 8 1-Ethyl-2,3-dimethylimidazolium ethyl sulfate, 8 BASF quality, ≥95%

BASF quality, ≥95% CH C6H11AlCl4N2 3 + CH N C9H18N2O4S 3 FW: 279.96 – H3C AlCl4 FW: 250.32 N+ mp: 9 °C N CH O mp: 67 °C N 3 O [80432-05-9] H3C S O O- [516474-08-1] H3C 51059-100G 100 g 118.80 05338-100G 100 g 79.20 51059-1KG 1 kg 327.90 05338-1KG 1 kg 218.60 1-Ethyl-3-methylimidazolium thiocyanate, 8 1-Ethyl-3-methylimidazolium acetate, 8 BASF quality, ≥95% BASF quality, ≥90% CH3 C7H11N3S CH + C8H14N2O2 3 N + FW: 169.25 – FW: 170.21 N SCN mp: -6 °C N mp: <-20 °C N O [331717-63-6] H3C H3C - [143314-17-4] OCH3

51053-100G 100 g 217.80 43437-100G 100 g 178.20 51053-1KG 1 kg 601.20 43437-1KG 1 kg 491.80

1-Ethyl-3-methylimidazolium chloride, 8 1-Methylimidazolium chloride, 8 BASF quality, ≥95% BASF quality, ≥95% CH C6H11ClN2 3 NH+ + - C4H6N2 · HCl N Cl Cl- FW: 146.62 FW: 118.56 N N mp: 80 °C mp: 75 °C CH3 [65039-09-0] H3C [35487-17-3] 30764-100G 100 g 99.00 40477-100G 100 g 89.10 30764-1KG 1 kg 273.20 40477-1KG 1 kg 246.00

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 7

1-Methylimidazolium hydrogen sulfate, 8 1,2,3-Trimethylimidazolium methyl sulfate, 8 BASF quality, ≥95% BASF quality, ≥95% CH NH+ 3 C4H6N2 · H2SO4 HO C7H14N2O4S + O N H CO FW: 180.18 S FW: 222.26 3 O N O - S O CH3 N O - mp: 39 °C CH3 mp: 113 °C O CH [681281-87-8] [65086-12-6] 3 59760-100G 100 g 89.10 59760-1KG 1 kg 246.00 50365-100G 100 g 79.20 50365-1KG 1 kg 218.60 Tributylmethylammonium methyl sulfate, 8 BASF quality, ≥95%

C14H33NO4S (CH2)3CH3 H CO FW: 311.48 + 3 O H3C N (CH2)3CH3 S O - mp: 62 °C (CH2)3CH3 O [13106-24-6] 38938-100G 100 g 59.40 ™ 38938-1KG 1 kg 163.90

References 1. Tsuda, T.; Hussey, C.L.; Stafford, G.R. Electrochem. Soc. 2002, 18. Earle, M.J.; Katdare, S.P. PCT Int. Appl. 2002, 20 pp. CODEN:

2002–19 (Molten Salts XIII), 650–659. PIXXD2 WO 2002030878. BASIONICS 2. Huang, J.-F.; Sun, I.-W. Electrochim. Acta 2004, 49, 3251–3258. 19. Carlin, R.T.; De Long, H.C.; Fuller, J.; Trulove, P.C. J. Electrochem. Soc. 1994, 141, L73–L76. 3. Endres, F.; Bukowski, M.; Hempelmann, R.; Natter, H. Angew. Chem., Int. Ed. 2003, 42, 3428–3430. 20. Murphy, V. PCT Int. Appl. 2000, 36 pp. CODEN: PIXXD2 WO 2000032658. 4. Myllymaeki, V.; Aksela, R. PCT Int. Appl. 2005, 25 pp. CODEN: PIXXD2 WO 2005023873. 21. Mann, B.E.; Guzman, M.H. Inorg. Chim. Acta 2002, 330, 143– 148. 5. Myllymaeki, V.; Aksela, R. PCT Int. Appl. 2005, 25 pp. CODEN: PIXXD2 WO 2005017001. 22. (a) Acevedo, O.; Evanseck, J.D. ACS Symposium Series 2003, 856 (Ionic Liquids as Green Solvents), 174–190. (b) C.W. Lee, 6. Phillips, D. M.; Drummy, L. F.; Conrady, D. G.; Fox, D. M.; Naik, Tetrahedron Lett. 1999, 40, 2461–2464. R. R.; Stone, M. O.; Trulove, P. C.; De Long, H. C.; Mantz, R. A. J. Am. Chem. Soc. 2004, 126, 14350–14351. 23. (a) Schoonover, R.E. U.S. Pat. Appl. 2003, 10 pp. CODEN: USXXCO US 2003085156. (b) Boesmann, A.; Datsevich, L.; Jess, 7. Griesbach, U.; Quaiser, C.; Hermeling, D.; Bottke, N.; Schubert, A.; Lauter, A.; Schmitz, C.; Wasserscheid, P. Chem. Commun. M.; Urtel, H. PCT Int. Appl. 2004, 23 pp. CODEN: PIXXD2 WO 2001, 2494–2495. 2004106316. 24. Qiao, C.-Z.; Zhang, Y.-F.; Zhang, J.-C.; Li, C.-Y. Appl. Catal. A: 8. Hell, K.; Hesse, U.; Weyershausen, B. Eur. Pat. Appl. 2004, 13 General, 2004, 276, 61–66. pp. CODEN: EPXXDW EP 1382630. 25. Mohile, S.S.; Potdar, M.K.; Salunkhe, M.M. Tetrahedron Lett. 9. Volland, M.; Seitz, V.; Maase, M.; Flores, M.; Papp, R.; 2003, 44, 1255–1258. Massonne, K.; Stegmann, V.; Halbritter, K.; Noe, R.; Bartsch, M.; Siegel, W.; Becker, M.; Huttenloch, O. PCT Int. Appl. 2003, 111 26. Olivier, H.; Chauvin, Y. Chemical Industries (Dekker) 1996, 68 pp. CODEN: PIXXD2 WO 2003062251. (Catalysis of Organic Reactions), 249–263. 10. Wu, H.-H.; Sun, J.; Yang, F.; Tang, J.; He, M.-Y. Chin. J. Chem. 27. Kadokawa, J.-I.; Iwasaki, Y.; Tagaya, H. Macromol. Rap. Comm. 2004, 22, 619–621. 2002, 23, 757–760. 11. Takahashi, S.; Akimoto, K.; Saeki, I.; Akama, R.; Oku, K. Jpn. 28. Vaher, M.; Koel, M.; Kaljurand, M. Electrophoresis 2002, 23, Kokai Tokkyo Koho 1990, 5 pp. CODEN: JKXXAF JP 02080589. 426–430. 12. Takahashi, S.; Akimoto, K.; Saeki, I.; Akama, R.; Oku, K. Jpn. 29. Eßer, J.; Wasserscheid, P.; Jess, A. Green Chem. 2004, 6, 316–322. Kokai Tokkyo Koho 1990, 5 pp. CODEN: JKXXAF JP 02097691. 30. Brennecke, J. F.; Maginn, E. J. U.S. Pat. Appl. 2002, 17 pp. 13. Maase, M.; Budich, M.; Grossmann, G.; Szarvas, L. PCT Int. CODEN: USXXCO US 2002189444. Appl. 2005, 31 pp. CODEN: PIXXD2 WO 2005019137. 31. Itoh, T.; Ouchi, N.; Hayase, S.; Nishimura, Y. Chem. Lett. 2003, 32, 14. Singh, V.; Kaur, S.; Sapehiyia, V.; Singh, J.; Kad, G. L. Catal. 654–655. Commun. 2005, 6, 57–60. 32. (a) Meng, Q. B.; Takahashi, K; Zhang, X. T.; Sutanto, I.; Rao, T. 15. Andre, M.; Loidl, J.; Laus, G.; Schottenberger, H.; Bentivoglio, N.; Sato, O.; Fujishima, A.; Watanabe, H.; Nakamori, T.; Uragami, G.; Wurst, K.; Ongania, K.-H. Anal. Chem. 2005, 77, 702–705. M. Langmuir 2003, 19, 3572–3574. (b) Wang, P.; Zakeeruddin, S. M.; Humphry-Baker, R.; Graetzel, M. Chem. Mater. 2004, 16, 16. Zhao, G.; Jiang, T.; Gao, H.; Han, B.; Huang, J.; Sun, D. Green 2694–2696. Chem. 2004, 6, 75–77. 33. Tsukahara, J.; Shiratsuchi, K.; Kubota, T.; Sen, S. Eur. Pat. Appl. 17. Wasserscheid, P.; Sesing, M.; Korth W. Green Chem. 2002, 4, 2001, 36 pp. CODEN: EPXXDW EP 1107333. 134–138. 34. Swatloski, R. P.; Spear, S. K.; Holbrey, J. D.; Rogers, R. D. J. Am. Chem. Soc. 2002, 124, 4974–4975.

Ionic Liquids for Catalysis

Annegret Stark and Bernd Ondruschka, Friedrich-Schiller-University, Influence of water impurity Institute for Technical Chemistry and Environmental Chemistry, Lessingstr. 12, 07743 Jena, Germany; [email protected]. 70 60 Ionic Liquids have been thoroughly investigated as solvents in most

% 50 types of catalytic reactions.1–4 Their merit lies in the ease with which 0.24 mol % their physical–chemical properties can be tuned by varying either the 40 2.04 mol % anion, the cation, or its substitution pattern. By this means, an Ionic 30 88.44 mol % Liquid with optimal properties (viscosity, solubility of substrates and 20 168.26 mol % Conversion /

products, etc.) for a given application can be designed (i.e, designer 10 solvents).5 In catalysis, this feature can be favorably exploited by 0 rendering a homogeneous reaction mixture bi-phasic, thus combining 0 50 100 150 200 250 300 the advantages of homogeneous and heterogeneous catalysis. An t / min. alternative to phase separation is the removal of products by thermal Figure 1. Influence of added increments of water to pure BMIM BF4 on the means; because of the negligibly low vapor pressure of Ionic Liquids, conversion of the metathesis of 1-octene at room temperature, as a function of the solvent and catalyst can be retained quantitatively during distillation time. Reaction conditions: 0.02 mol % catalyst precursor (relative to 1-octene), processes. Ionic Liquid:1-octene = 1:1 (vol.) The following examples illustrate that many catalysts possess a high activity in the Ionic Liquid solvent, and product separation is achieved However, the presence of traces of chloride exhibits a much more by facile phase separation. pronounced effect, as shown in Figure 2. A ratio of chloride:catalyst of 2.3 (0.07 mol % chloride in Ionic Liquid, corresponding to only As early as 1995, Chauvin et al. demonstrated that high conversions 100 ppm) reduced the turn-over frequency from 820 to 700 h-1. and selectivities are obtained in the rhodium-catalyzed hydrogenation, isomerization, or hydroformylation of alkenes in the presence Influence of chloride impurity of Ionic Liquids. Specifically, Ionic Liquids based on anions with modest coordination ability, such as 1-butyl-3-methylimidazolium 70

hexafluoroantimonate (BMIM SbF6, Prod. # 51027), 1-butyl-3- 60

methylimidazolium hexafluorophosphate (BMIM PF6), and 1-butyl-3- 0.00 mol % 50

methylimidazolium tetrafluoroborate (BMIM BF4), gave better results % 0.07 mol %

Ionic Liquids for Catalysis 6 when compared to mono-phasic molecular solvents. 40 0.28 mol %

0.69 mol % Scandium- or platinum(II)-catalyzed Diels–Alder reactions in either 30 51.00 mol %

BMIM PF6, BMIM SbF6, 1-butyl-3-methylimidazolium trifluoromet Conversion / 20 hanesulfonate (BMIM CF3SO3), and 1-butyl-3-methylimidazolium 10 bis(trifluoromethylsulfonyl)imide (BMIM N(CF3SO2)2) were also investigated. Very high endo/exo ratios (>99/1) and improved reaction 0 rates were achieved when compared to dichloromethane. Efficient 0 100 200 300 400 recycling was demonstrated for ten cycles on the example of the t / min. 7,8 reaction of methyl vinyl ketone and 2,3-dimethylbuta-1,3-diene. Figure 2. Influence of added increments of 1-hexyl-3-methylimidazolium chloride Ionic Liquids also have been studied as solvents in bio-catalysis. For (HMIM Cl) to pure BMIM BF4 on the conversion of the metathesis of 1-octene example, high enantiomeric excesses were obtained in the lipase- at room temperature, as a function of time. Reaction conditions: 0.03 mol % catalyst precursor (relative to 1-octene), Ionic Liquid:1-octene = 1:1 (vol.). catalyzed trans-esterification of various substrates4,9–11 in Ionic Liquids based on the 1-alkyl-3-methylimidazolium or 4-methyl- Interestingly, the catalyst precursor is most sensitive to the presence N-alkylpyridinium cation and anions such as tetrafluoroborate, of traces of 1-methylimidazole. Figure 3 shows that residual 1-methyl- hexafluorophosphate, trifluoromethanesulfonate, etc. This finding imidazole in an Ionic Liquid deactivates the catalyst fully at a ratio was attributed to interactions of the Ionic Liquid with the enzyme, of 6.3:1 1-methylimidazole:catalyst, which corresponds to traces of altering the selectivity of a biocatalytic reaction. Additionally, both 0.18 mol % (600 ppm) of 1-methylimidazole in the Ionic Liquid. the Ionic Liquid and enzyme were recyclable after extraction of the products from the Ionic Liquid phase with diethyl ether.10 Influence of 1-methylimidazole impurity Several researchers have found that impurities in Ionic Liquids exhibit an influence on the reaction outcome in catalysis.4,6,12–22 Nevertheless, the 70 quantitative specification of each batch of Ionic Liquid used is seldom 60 reported, and the comparison of results from different laboratories is % 50 0.00 mol % thus hampered. 40 0.06 mol % 30 0.12 mol % Impurities, such as water, unreacted amine (e.g., 1-methylimidazole), 20 0.18 mol % Conversion / and traces of halides most frequently stem from the preparation of 10 Ionic Liquids. In the example of the metathesis of 1-octene catalyzed by 0 Grubbs’ 1st generation catalyst, Sigma-Aldrich’s high purity 1-butyl- 0 100 200 300 400 3-methylimidazolium tetrafluoroborate (Prod. # 39931) or 1-ethyl- t / min.

3-methylimidazolium tetrafluoroborate (Prod. # 39736, were spiked Figure 3. Influence of added increments of 1-methylimidazole to pure BMIM BF4 with known amounts of either of these impurities (water <200 ppm, on the conversion of the metathesis of 1-octene at room temperature as a halogens (Cl-) <10 ppm) to demonstrate the importance of the quality function of time. Reaction conditions: 0.03 mol % catalyst precursor (relative to of Ionic Liquids employed in catalysis. 1-octene), Ionic Liquid:1-octene = 1:1 (vol.).

Figure 1 shows that the catalyst is relatively resistant to the presence of Sigma-Aldrich is pleased to introduce a new set of highly purified Ionic water, and even a 100-fold excess of water over catalyst (2.04 mol % Liquids for catalysis with water contents below 200 ppm and halogen water in Ionic Liquid) does not inhibit the reaction significantly. content (Cl-) below 10 ppm.

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 9

1-Ethyl-3-methylimidazolium tetrafluoroborate 8 1-Butyl-3-methylimidazolium tetrafluoroborate 8 for catalysis, ≥98.5% T for catalysis, ≥98.5% T CH C H BF N CH3 C H BF N 3 6 11 4 2 8 15 4 2 + N+ N – – FW: 197.97 BF4 FW: 226.02 BF4 mp: 11 °C N mp: -71 °C N [143314-16-3] CH3 [174501-65-6] 39736-5ML 5 mL 262.00 CH3 39736-50ML 50 mL 720.50 39931-5G 5 g 105.00 1-Butyl-3-methylimidazolium chloride, dry, ≥99% AT 8 39931-50G 50 g 315.00 C H ClN CH3 8 15 2 + N - 1-Butyl-1-methylpyrrolidinium dicyanamide, ≥99% 8 FW: 174.67 Cl N mp: 41 °C C11H20N4 N+ CN - [79917-90-1] FW: 208.30 CH3 N H3C [370865-80-8] CN

55509-5G 5 g 57.40 CH3 55509-25G 25 g 229.30 50893-5G 5 g 240.80 1-Butyl-3-methylimidazolium chloride, 8 50893-50G 50 g 662.30 puriss., dry, ≥99% AT

CH3 1-Butyl-3-methylimidazolium hexafluoroantimonate, 8 C8H15ClN2 N+ ≥98% FW: 174.67 Cl– N mp: 41 °C C H F N Sb CH3 8 15 6 2 N+

[79917-90-1] FW: 374.97 - N SbF6 CH3 mp: -1 °C 04129-5G 5 g 53.60 [174645-81-9] H C 04129-25G 25 g 214.30 3

1-Butyl-3-methylimidazolium hexafluorophosphate 8 51027-5G 5 g 73.60 for catalysis, ≥98.5% T 51027-50G 50 g 220.80 Ionic Liquids for Catalysis

CH3 C8H15F6N2P N+ – FW: 284.18 PF6 mp: 11 °C N [174501-64-5]

CH3 18122-5G 5 g 114.80 18122-50G 50 g 820.00

References 1. Holbrey, J. D.; Seddon, K. R. Clean Prod. Proc. 1999 1, 223. 13. Suarez, P. A. Z.; Dullius, J. E. L.; Einloft, S.; de Souza, R. F.; Dupont, J. Inorg. Chim. Acta 1997, 255, 207. 2. Wasserscheid, P.; Keim, W. Angew. Chem. Int. Ed. 2000 3, 3772. 14. Monteiro, A. L.; Zinn, F. K.; de Souza, R. F.; Dupont, J. 3. Welton, T. Coord. Chem. Rev. 2004, 248, 2459. Tetrahedron: Asymmetry 1997, 8, 177. 4. Sheldon, R. A.; Madeira, R.; Lau, R. M.; Sorgedrager, M. J.; van 15. Dyson, P. J.; Ellis, D. J.; Parker D. G.; Welton, T. Chem. Commun. Rantwijk, F.; Seddon, K. R. Green Chem. 2002, 4, 147. 1999, 25. 5. Freemantle, M. Chem. Eng. News 1998, 76, 32. 16. Ellis, B.; Keim, W.; Wasserscheid, P. Chem. Commun. 1999, 337. 6. Chauvin, Y.; Olivier-Bourbigou, H. Chemtech. 1995, 26, 26. 17. Carmichael, A. J.; Earle, M. J.; Holbrey, J. D.; McCormac, P. B.; 7. Song, C. E.; Shim, W. H.; Roh, E. J.; Lee, S. C.; Choi, J. H. Chem. Seddon, K. R. Org. Lett. 1999, 1, 997. Commun. 2001, 1122. 18. Dyson, P. J.; Ellis, D. J.; Lincoln, R.; Russel, K.; Smith, P. J.; 8. Doherty, S.; Goodrich, P.; Hardacre, C.; Luo, H. K.; Rooney, D. Welton, T. Electrochem. Soc. Proc. 2000, 99-41, 161. W.; Seddon, K. R.; Styring, P. Green Chem. 2004, 6, 63. 19. Song, C. E.; Roh, E. J. Chem. Commun. 2000, 837. 9. Schöfer, S. H.; Kaftzik, N.; Wasserscheid, P.; Kragl, U. Chem. 20. Seddon, K. R.; Stark, A. Green Chem. 2002, 119. Commun. 2001, 425. 21. de Souza, R. F.; Rech,; V. Dupont, J. Adv. Synth. Catal. 2002, 10. Itoh, T.; Akasaki, E.; Kudo, K.; Shirakami, S. Chem. Lett. 2001, 262. 344, 153. 11. Lozano, P.; de Diego, T.; Carrie, D.; Vaultier, M.; Iborra, J. L. 22. Klingshirn, M. A.; Broker, G. A.; Holbrey, J. D.; Shaughnessy, K. Chem. Commun. 2002, 692. H.; Rogers, R. D. Chem. Commun. 2002, 1394. 12. Chauvin, Y.; Mussmann, L.; Olivier, H. Angew. Chem. Int. Ed. 1996, 34, 2698.

Ionic Liquids for Electrochemical Applications

Over the past decade, Ionic Liquids have attracted much interest for Applications their use as non-aqueous electrolytes in electrochemical applications. a) High Conductivity In this context, their conductivity as well as their electrochemical The materials showing the highest conductivities, 1-ethyl-3-methylimi- stability are the most important physical properties. Together with dazolium thiocyanate and dicyanamide exhibited the lowest electro- other interesting properties such as their negligible vapor pressure and chemical stabilities. Nevertheless, these materials are good candidates their non-flammability, they appear to be ideal electrolytes for many for use in any application where a high conductivity combined with interesting applications as already described and discussed in a growing thermal stability and non-volatility is necessary, e.g., 1-dodecyl-3- number of publications.1 methylimidazolium iodide (Prod. # 18289) in dye-sensitized solar cells.2 Conductivity b) High Stability As mentioned above, one very interesting property is their conductivity. The electrochemically most stable materials having comparable small Typical values are in the range from 1.0 mS/cm to 10.0 mS/cm. Recently, conductivities (N-butyl-N-methylpyrrolidinium bis(trifluoromethyl- interesting materials with conductivities above 20 mS/cm based on the sulfonyl)imide (Prod. # 40963), triethylsulphonium bis(trifluoromethyl- imidazolium-cation were described: 1-ethyl-3-methylimidazolium thio- sulfonyl)imide (Prod. # 08748), and N-methyl-N-trioctylammonium cyanate (Prod. # 07424) and 1-ethyl-3-methylimidazolium dicyanamide bis(trifluoromethylsulfonyl)imide (Prod. # 00797). These materials are 3 4 5 (Prod. # 00796). good electrolytes for use in batteries, fuel cells, metal deposition, and electrochemical synthesis of nano-particles.6 NN NN c) Combined Properties For applications where conductivity and electrochemical stability are 7 8 SCN N(CN)2 needed (e.g., supercapacitors or sensors ), imidazolium-based Ionic Applications Of course, a solution of a typical inorganic salt such as sodium chloride Liquids with stable anions (e.g., tetrafluoroborate or trifluoromethylsul in water shows a higher conductivity. But if we compare other properties fonate) are the materials of choice. Electrochemical Electrochemical Ionic Liquids for of this solution with an Ionic Liquid, significant disadvantages become Sigma-Aldrich now offers a set of Ionic Liquids especially useful for your obvious: aqueous electrolytes are liquid over a smaller temperature electrochemical applications. range and the solvent water is volatile! Electrochemical Stability 1-Butyl-2,3-dimethylimidazolium tetrafluoroborate 8 for electrochemistry, ≥99% Another very important property of Ionic Liquids is their wide electrochemical window, which is a measure for their electrochemical stability C9H17BF4N2 CH3 + against oxidation and reduction processes: FW: 240.05 N mp: 37 °C N CH3 – BF4 Cation + e neutral species [402846-78-0]

Anion neutral species + e CH3

Obviously, the electrochemical window is sensitive to impurities: halides 04383-5G 5 g 75.40 are oxidized much easier than molecular anions (e.g., stable fluorine- 04383-50G 50 g 226.10 containing anions such as bis(trifluoromethylsulfonyl)imide), where the negative charge is delocalized over larger volume. As a consequence, 1-Butyl-1-methylpyrrolidinium bis(trifluoromethyl- 8 contamination with halides leads to significantly lower electrochemical sulfonyl)imide for electrochemistry, ≥99.5% stabilities. C11H20F6N2O4S2 CF Cation stability: + O 3 FW: 422.41 N S CH3 O -N mp: -50 °C O R S R2 2 O NN CF3 < R1 S R1 N R3 N < R2 R2 < CH3 R3 R R 4 40963-5G 5 g 116.30 Anion stability: 40963-50G 50 g 319.80

Hal < AlCl4 < PF6, BF4 < N(SO2CF3)2 1-Dodecyl-3-methylimidazolium iodide 8

Conductivities and Electrochemical Windows C16H31IN2 (CH2)11CH3 FW: 378.34 N+ of Selected Materials I- Electrochemical [81995-09-7] N Ionic Liquid Conductivity Window CH3 a) Highly Conductive 18289-5G 5 g 166.60 1-Ethyl-3-methylimidazolium dicyanamide 27 mS/cm 2.9 V 18289-50G 50 g 458.30 1-Ethyl-3-methylimdazolium thiocyanate 21 mS/cm 2.3 V b) Electrochemically Stable 1-Ethyl-2,3-dimethylimidazolium trifluoromethane- 8 Triethylsulphonium bis(trifluoromethylsulfonyl)imide 8.2 mS/cm 5.5 V sulfonate for electrochemistry, ≥99%

N-Methyl-N-trioctylammonium bis(trifluoro- 2.2 mS/cm 5.7 V C8H13F3N2O3S CH3 methylsulfonyl)imide N+ FW: 274.26 F3C O S N-Butyl-N-methylpyrrolidinium bis(trifluoro- 2.1 mS/cm 6.6 V CH3 O [174899-72-0] N O- methylsulfonyl)imide H3C c) Combined Properties 1-Ethyl-3-methylimidazolium tetrafluoroborate 12 mS/cm 4.3 V 00765-5G 5 g 158.10 00765-50G 50 g 434.90 1-Ethyl-3-methylimidazolium trifluoromethylsulfonate 8.6 mS/cm 4.3 V

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 11

1-Ethyl-3-methylimidazolium dicyanamide 8 Tetraethylammonium trifluoromethanesulfonate, purum, ≥98% T for electrochemistry, ≥99% C9H20F3NO3S CH2CH3 F3C CH + O C8H11N5 3 FW: 279.32 H3CH2C N CH2CH3 S + O N O- FW: 177.21 CN mp: 161–163 °C CH2CH3 - N N mp: -21 °C CN [35895-69-3] [370865-89-7] H3C 86651-5G 5 g 57.60 00796-5G 5 g 158.10 86651-25G 25 g 255.40 00796-50G 50 g 434.90 Triethylsulfonium bis(trifluoromethylsulfonyl)imide 8 1-Ethyl-3-methylimidazolium nitrate, purum, ≥99% NT for electrochemistry, ≥99% CF C H N O CH3 C8H15F6NO4S2 O 3 6 11 3 3 + S N NO – + O 3 FW: 367.26 S N– FW: 173.17 O N S mp: 38 °C O CF3 [143314-14-1] H3C

04363-1G 1 g 41.90 08748-5G 5 g 77.40 04363-5G 5 g 142.90 08748-50G 50 g 232.30

1-Ethyl-3-methylimidazolium tetrafluoroborate 8 Tetrabutylammonium bromide puriss., for electrochemistry, ≥99% electrochemical grade, ≥99% T

CH3 C16H36BrN C6H11BF4N2 (CH2)3CH3 + N + - – FW: 322.37 H3C(H2C)3 N (CH2)3CH3 Br FW: 197.97 BF4 Applications mp: 11 °C N mp: 102–104 °C (CH2)3CH3 [1643-19-2] [143314-16-3] H3C Electrochemical Electrochemical 86836-10G 10 g 71.10 Ionic Liquids for 00768-5G 5 g 163.70 86836-50G 50 g 280.80 00768-50G 50 g 450.20 Tetrabutylphosphonium tetrafluoroborate, puriss., 1-Ethyl-3-methylimidazolium thiocyanate 8 electrochemical grade, ≥99% T for electrochemistry, ≥98% C16H36BF4P (CH2)3CH3 CH3 + C7H11N3S H C(H C) P (CH ) CH - N+ FW: 346.24 3 2 3 2 3 3 BF4 FW: 169.25 – SCN mp: 96–99 °C (CH2)3CH3 N mp: -6 °C [1813-60-1] [331717-63-6] H3C 86934-5G 5 g 52.90 07424-5G 5 g 164.60 86934-25G 25 g 209.30 07424-50G 50 g 452.60 Sigma-Aldrich offers, in collaboration with Covalent Associates, Inc., a 1-Ethyl-3-methylimidazolium trifluoromethane 8 set of hydrophobic Ionic Liquids exhibiting excellent thermal stabilities sulfonate for electrochemistry, ≥99% and resistance to water and oxygen.

CH3 C7H11F3N2O3S N+ 1-Butyl-3-methylimidazolium bis(trifluoromethyl- 8 FW: 260.23 F3C O N S sulfonyl)imide, purum, ≥98% NMR mp: -9 °C O O- H3C CH3 [145022-44-2] C10H15F6N3O4S2 N+ FW: 419.36 O O N– 00738-5G 5 g 159.40 N S S [174899-83-3] F C CF 00738-50G 50 g 438.40 3 O O 3

CH3 Methyl-trioctylammonium bis(trifluoromethyl- 8 sulfonyl)imide for electrochemistry, ≥99% 77896-1G 1 g 76.60 77896-5G 5 g 334.30 C27H54F6N2O4S2 O CF3 (CH2)7CH3 S FW: 648.85 + - O H3C N (CH2)7CH3 N O 1-Butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide S mp: -50 °C (CH2)7CH3 O CF3 purum, ≥97% H-NMR [375395-33-8] CH3 C12H16F6N2O4S2 O CF3 00797-5G 5 g 87.10 S FW: 430.39 N+ O -N 00797-50G 50 g 239.70 O [344790-86-9] S O CF3 Tetrabutylammonium bis(trifluoromethylsulfonyl)imide, H3C puriss., for electronic purposes, ≥99% T 14654-1G 1 g 96.70 C18H36F6N2O4S2 (CH ) CH O CF3 2 3 3 S 14654-5G 5 g 386.90 FW: 522.61 + O H3C(H2C)3 N (CH2)3CH3 -N O S mp: 94–96 °C (CH2)3CH3 O [210230-40-3] CF3

86838-1G 1 g 23.00 86838-5G 5 g 90.50

1,2-Dimethyl-3-propylimidazolium bis(trifluoromethyl- 3-Methyl-1-propylpyridinium bis(trifluoromethylsulfonyl)- sulfonyl)imide purum, ≥97% H-NMR imide, purum CH C H F N O S CH3 C H F N O S 3 10 15 6 3 4 2 CF 11 14 6 2 4 2 CF3 + O 3 O FW: 419.36 N S FW: 416.36 + S N - O - O N CH N O mp: 15 °C N 3 O mp: 0 °C S S O CH3 O CF3 [169051-76-7] CF3 CH3 50807-1G 1 g 148.60 30565-1G 1 g 96.70 50807-5G 5 g 594.20 30565-5G 5 g 386.90

1,2-Dimethyl-3-propylimidazolium tris(trifluoromethyl- References sulfonyl)methide purum, ≥97% H-NMR 1. For a general overview: Trulove, C.; Mantz, R. A. “Ionic Liquids in C H F N O S CH3 12 15 9 2 6 3 O CF3 Synthesis”, Chapter 3.6: Electrochemical Properties of Ionic Liquids, O S FW: 550.44 N+ - O (P. Wasserscheid, T. Welton eds.), Wiley-VCH, Weinheim, 2003. F3C S C O [169051-77-8] N CH3 O S O CF 2. Yamanaka, N.; Kawano, R.; Kubo, W.; Kitamura, T.; Wada, Y.; CH3 3 Watanabe, M.; Yanagida, S. Chem. Commun. 2005, 740–742. 74305-1G 1 g 180.00 3. Wilkes, J. S.; Levisky, J. A.; Wilson, R. A. Inorg. Chem. 1982, 74305-2.5G 2.5 g 386.90 21, 1263–1264. Garcia, B.; Lavallée, S.; Perron, G.; Michot, C.; 1-Ethyl-3-methylimidazolium bis(pentafluoroethylsulfonyl)- Armand, M. Electrochim. Acta 2004, 49, 4583–4588. imide purum, ≥97% H-NMR 4. Yanes, E. G.; Gratz, S. R.; Baldwin, M. J. Anal. Chem. 2001, 73,

CH3 C H F N O S F3CF2C 3838–3844. 10 11 10 3 4 2 + O Applications N S FW: 491.33 O -N 5. (a) Zell, C. A.; Freyland, W. Langmuir 2003, 19, 7445–7450. N mp: -1 °C S O

Electrochemical Electrochemical (b) Scheeren, C. W.; Machado, G.; Dupont, J.; Fichtner, P. F. P.;

Ionic Liquids for O [216299-76-2] H3CF3CF2C Texeira, S. R. Inorg. Chem. 2003, 42, 4738–4742. (c) Huang, J.-F.; 39056-1G 1 g 202.90 Sun, I.-W. J. Chromat. A 2003, 1007, 39–45. 39056-5G 5 g 810.30 6. (a) Zhou, Y.; Antonietti, M. J. Am. Chem. Soc. 2003, 125, 14960– 14961. (b) Zhou, Y.; Antonietti, M. Chem. Mater. 2004, 16, 544– 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)- 550. imide purum, ≥97% H-NMR

CH3 7. Sato, T.; Masuda, G.; Takagi, K. Electrochim. Acta 2004, 49, C H F N O S O 8 11 6 3 4 2 N+ 3603–3611. FW: 391.31 O S CF3 - mp: -17 °C N N 8. See: http://www.iolitec.de. O S CF3 H3C [174899-82-2] O 11291-1G 1 g 148.60 11291-5G 5 g 605.20

Get Your FREE Ionic Liquids Poster by contacting your local Sigma-Aldrich office (see back cover)

Over 100 products

• Melting Points • Viscosities • Densities • Miscibilities with: · Water · Isopropanol · Acetone · Acetonitrile · Toluene · Heptane • Conductivities • EC windows TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 13

Enzymatic Reactions in Ionic Liquids

Dr. F. Bordusa, Max Planck Research Unit for Enzymology of Protein O O Folding, Weinbergweg 22, 06120 Halle/Saale, Germany. PEG-Lipase O CH2 O During the last years, a number of enzyme-mediated synthesis reactions in Ionic Liquids were established. In comparison to reactions Scheme 5 in classical organic solvents, they showed usually higher enzyme The PS-C lipase from Pseudomonas cepacia hydrolyzes 3,4,6-tri- activities and stabilities. Furthermore, the regio-, stereo-, and enantio- O-acetyl-D-glucal (Scheme 6). In 1-butyl-3-methylimidazolium selectivites were improved. hexafluorophosphate, the regioselectivity is increased up to 80%, Recently, lipases showed the most promising results in Ionic Liquids. whereas the regioselectivity in THF is lower than 20%.8 One of the most popular lipase for synthetic use is the candida OAc OAc antarctica lipase (CALB). CALB catalyzes the enantioselective acylation O O of 1-phenylethylamine with 4-pentenoic acid (Scheme 1). PS-C-lipase

AcO AcO CH3 O CH3 CH CALB 3 + + OAc Scheme 6 OH Ph NH2 R OH Ph NH2 Ph NHCOR

R = CH2=CHCH2CH2- The serine-protease α-chymotrypsin mediates the synthesis of N-acetyl- L-tyrosine propyl ester through a trans-esterification reaction in Ionic Scheme 1 Liquids starting from the ethyl ester. In 1-butyl-3-methylimidazolium In Ionic Liquids, the enantiomeric excess of the resulting amide is over hexafluorophosphate and 1-ethyl-3-methylimidazolium bis(trifluoro- 1 99%. In a solvent-free system, only 59% ee was achieved. The highest methylsulfonyl)imide (Prod. # 11291), α-chymotrypsin shows a clear conversion rates are reached in 1-butyl-2,3-dimethylimidazolium trifluoro- enhancement in enzyme stability and conversion rates in comparison Ionic Liquids methanesulfonate (Prod. # 00765) and 1-ethyl-3-methylimidazolium to propanol.9 BL-alcalase, a commercially available serine-type endo- trifluoromethanesulfonate (Prod. # 04367).2 proteinase from Bacillus licheniforms, can catalyse the enzymatic Similarly, in CALB-mediated trans-esterification reactions with ethyl resolution of a homophenylalanine ester in Ionic Liquids (Scheme 7). butanoate, higher conversion rates were observed in 1-butyl-3- In 1-ethyl-3-methylimidazolium tetrafluoroborate (Prod. # 04365) and methylimidazolium hexafluorophosphate (Prod. # 70956) than in 4-ethylpyridinium tetrafluoroborate, high optical purity and yields are 10 classical organic solvents.3 achieved. Enzymatic Reactions in

NHAc NH Because of the stabilizing effect of Ionic Liquids, enzymatic resolution BL-alcalase 2 of a Lotrafiban-precursor with CALB allows an increase of the Ph CO2Et Ph CO2Et reaction temperature up to 75 °C if 1-butyl-3-methylimidazolium Scheme 7 hexafluorophosphate is used as solvent (Scheme 2). This leads to a four-fold enhancement of the initial rate of product formation Metalloproteases are applicable in Ionic Liquids. The zinc-protease compared to t-butanol.4 thermolysin is used for the enzymatic synthesis of (Z)-aspartame. Thermolysin activity in 1-butyl-3-methylimidazolium hexafluoro- H CO C HO C 3 2 2 phosphate reaches the same order of magnitude as in conventional H H N N CALB organic solvents. The enzymatic stability is as good as the stability of O O immobilized enzymes.11 N N CH3 CH3 Etherhydrolases also work in Ionic Liquids. The enzyme (recombinant Scheme 2 soluble epoxide hydrolase)12 hydrolyzes trans-β-methylstyrene oxide Also, candida rugosa lipase (CRL) shows activity in Ionic Liquids. Methyl- through a stereoconvergent process to give the corresponding optically 6-O-trityl-glucosides and galactosides can be acylated enzymatically active (1S,2R)-erythro-1-phenylpropane-1,2-diol (Scheme 8). In 1-butyl- by CRL (Scheme 3). The regioselectivity of this reaction is increased 3-methylimidazolium hexafluorophosphate, an enantiomeric excess of from 80% in THF to over 98% in 1-butyl-3-methylimidazolium 90% is achieved.13 5 hexafluorophosphate as solvent. OH O epoxide hydrolase CH3 OTr OTr Ph Ph CH3 HO H2C HO OH O OAc O Scheme 8 HO CRL HO OH OH OAc OH The β-galactosidase from Bacillus circulans is able to catalyze the Scheme 3 synthesis of N-acetyllactosamine in a trans-glycosylation reaction CRL similarly mediates the esterification of 2-substituted propanoic (Scheme 9). The addition of 25% 1,3-dimethylimidazolium dimethyl- acids with butanol (Scheme 4). The enantioselectivity of this reaction is sulfate suppresses the secondary hydrolysis of the product, which enhanced by using 1-methyl-3-octylimidazolium hexafluorophosphate doubles the yield of the reaction to almost 60% compared to 14 (Prod. # 69230). In this solvent, CRL can be recycled five times without conventional organic media. 6 appreciable decrease of activity or enantioselectivity. OH OH X X X HO O CRL HO HO O OH OH + OBu HO H3C H3C H3C OH Bu-OH AcHN OH OH O O O β-galactosidase + + X = Cl, Br, MeO, PrO, i-PrO, PhO HO OH OH Scheme 4 OH HO OH O O O HO O O The PEG-lipase PS from Pseudomonas cepacia can catalyze the HO HO O OH HO alcoholysis between vinyl cinnamate and benzyl alcohol (Scheme 5). OH OH AcHN AcHN OH This reaction proceeds with an eight-fold higher enzyme activity in Scheme 9 1-octyl-4-methylimidazolium hexafluorophospate than in an organic Sigma-Aldrich offers a collection of Ionic Liquids suitable for bioorganic solvent system.7 transformations and enzyme-mediated reactions.

1-Butyl-3-methylimidazolium hexafluorophosphate 1-Ethyl-3-methylimidazolium tosylate, purum, ≥98% T purum, ≥96% T C H N O S CH 13 18 2 3 3 SO – N+ 3 C8H15F6N2P CH3 FW: 282.36 + - FW: 284.18 N PF6 mp: 25–35 °C N N mp: 11 °C [328090-25-1] H3C CH [174501-64-5] 3 H3C 89155-5G 5 g 48.90 89155-50G 50 g 291.90 70956-5G 5 g 60.00 70956-50G 50 g 180.00 1-Hexyl-3-methylimidazolium tetrafluoroborate, 70956-250G 250 g 928.60 purum, ≥97% NMR

C10H19BF4N2 CH3 1-Butyl-3-methylimidazolium octyl sulfate, purum, 95% T N+ ≥ - FW: 254.08 BF4 N C16H32N2O4S CH3 mp: -81 °C FW: 348.50 N+ [244193-50-8] (CH2)5CH3 N O mp: 33 °C – OS O(CH2)7CH3 73244-5G 5 g 121.80 [445473-58-5] O 73244-50G 50 g 337.90 H3C 1-Methyl-3-octylimidazolium hexafluorophosphate, 8 75059-5G 5 g 32.80 purum, ≥95% T 75059-50G 50 g 194.80 C12H23F6N2P (CH2)7CH3

Ionic Liquids + FW: 340.29 N – 1-Butyl-3-methylimidazolium tosylate, ≥98.5% 8 PF6 mp: <-40 °C N – C15H22N2O3S CH3 SO3 [304680-36-2] CH3 FW: 310.41 N+ N 69230-5G 5 g 50.00 CH3 69230-25G 25 g 200.00 H3C Enzymatic Reactions in 1-Methyl-3-octylimidazolium tetrafluoroborate, 8 00806-5G 5 g 156.60 purum, ≥97% AT 00806-50G 50 g 430.70 C12H23BF4N2 CH3 + N – 1-Butyl-4-methylpyridinium tetrafluoroborate, purum, ≥97% T FW: 282.13 BF4 mp: -88 °C N C H BF N CH3 10 16 4 [244193-52-0] (CH2)7CH3 FW: 237.05

mp: <30 °C + - N BF4 [343952-33-0] 96324-5G 5 g 75.50 96324-50G 50 g 209.40 H3C References: 73261-5G 5 g 71.20 73261-50G 50 g 197.40 1 Irimescu, R. et al. Tetrahedron Lett. 2004, 45, 523. 2. Irimescu, R. et al. J. Mol. Catal. B: Enzym. 2004, 30, 189. 1,3-Dimethylimidazolium methyl sulfate, purum, ≥97% NMR 3. Lau, R. M et al. Org. Lett. 2000, 2, 4189. C6H12N2O4S CH3 + N H CO FW: 208.24 3 O 4. Roberts, N. J. et al. Green Chem. 2004, 6, 475. S N O [97345-90-9] O- 5. Kim, M.-J. et al. J. Mol. Catal. B: Enzym. 2003, 26, 115. CH3 6. Ulbert, O. et al. J. Mol. Catal. B: Enzym. 2004, 31, 39. 93607-5G 5 g 48.90 93607-50G 50 g 135.70 7. Maruyama, T. et al. Biotechnol. Lett., 2002, 24, 1341.

1-Ethyl-3-methylimidazolium tetrafluoroborate, purum, ≥97% T 8. Nara, S. J. et al. J. Mol. Catal. B: Enzym. 2004, 28, 39.

CH3 9. Lozano, P. et al. Biotechnol. Bioeng. 2001, 75, 563. C6H11BF4N2 N+ – FW: 197.97 BF4 10. Zhao, H. et al. Biotechnol. Prog. 2003, 19, 1016. mp: 11 °C N 11. Erbeldinger, M. et al. M. Biotechnol. Prog. 2000, 16, 1129. [143314-16-3] CH3 04365-1ML 1 mL 56.70 12. Morissea, C. et al. Arch. Biochem. Biophys. 2000, 378, 321. 04365-5ML 5 mL 177.60 13. Chiappe et al. J. Mol. Catal. B: Enzym. 2004, 27, 243. 04365-50ML 50 mL 373.30 14. Kaftzik, N. et al. Org. Process Res. Dev. 2002, 6, 553.

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 15

CYPHOS® Phosphonium Ionic Liquids

+ The phosphonium cation, with the generic formula [PR3R’] and with a Trihexyltetradecylphosphonium decanoate, purum 8 judicious selection of the appropriate anion, forms many phosphonium C H O P salts that are liquid at room temperature and many have melting points 42 87 2 (CH2)5CH3 FW: 655.11 + below 100 °C. H3C(H2C)5 P (CH2)13CH3 mp: -9 °C (CH2)5CH3 Phosphonium-based Ionic Liquids offer the following advantages: O H3C(H2C)8 – • Phosphonium salts are thermally more stable than the O corresponding ammonium salts and imidazolium salts. This is very important for processes which operate at temperatures 50826-5G 5 g 14.50 higher than 100 °C (e.g., removal of reaction products by 50826-50G 50 g 50.00 distillation). Furthermore, prevention of contaminations by decomposition products is a prerequisite for multiple recycle use Trihexyltetradecylphosphonium dicyanamide, purum 8

of solvents. C34H68N3P (CH2)5CH3 FW: 549.90 • Phosphonium cations lack acidic protons. Thus, they are stable H C(H C) P+ (CH ) CH mp: -50 °C 3 2 5 2 13 3 under basic conditions, which can be problematic for several (CH ) CH – 2 5 3 N imidazolium-based Ionic Liquids (carbene formation). NC CN • Phosphonium salts are, in general, less dense than water, which 56776-5G 5 g 18.10 might be beneficial in product work-up steps. 56776-50G 50 g 94.50 Sigma-Aldrich offers, in collaboration with Cytec Industries, Inc., a new class of Ionic Liquids based on phosphonium cations. Trihexyltetradecylphosphonium hexafluorophosphate, 8 Ionic Liquids purum Phosphonium ®

Trihexyltetradecylphosphonium bis(2,4,4-trimethyl- 8 C32H68F6P2 (CH2)5CH3 + pentyl)phosphinate, purum FW: 628.82 H3C(H2C)5 P (CH2)13CH3 [374683-44-0] (CH ) CH – 2 5 3 PF6 C48H102O2P2 (CH2)5CH3 + FW: 773.27 H3C(H2C)5 P (CH2)13CH3 40573-5G 5 g 18.10 CYPHOS (CH2)5CH3 mp: -71 °C H3C CH3 P 40573-50G 50 g 94.50 t-Bu O O– t-Bu Trihexyltetradecylphosphonium tetrafluoroborate, 8 28612-5G 5 g 14.50 purum 28612-50G 50 g 50.00 (CH ) CH C32H68BF4P 2 5 3 + Trihexyltetradecylphosphonium bis(trifluoromethyl- 8 FW: 570.66 H3C(H2C)5 P (CH2)13CH3 – sulfonyl)amide, purum mp: 17 °C (CH2)5CH3 BF4 [374683-55-3] C34H68F6NO4PS2 (CH2)5CH3 + 15909-5G 5 g 14.50 FW: 764.00 H3C(H2C)5 P (CH2)13CH3 15909-50G 50 g 50.00 mp: -50 °C (CH2)5CH3 – [460092-03-9] F CO S N SO CF 3 2 2 3 Triisobutylmethylphosphonium tosylate, purum 8

C H O PS – 50971-5G 5 g 28.90 20 37 3 CH3 SO3 FW: 388.54 50971-50G 50 g 178.80 H3C + mp: -50 °C P CH3 H3C Trihexyltetradecylphosphonium bromide, purum [344774-05-6] CH3 CH 8 CH3 3 CH3 C32H68BrP (CH2)5CH3 + FW: 563.76 H3C(H2C)5 P (CH2)13CH3 90145-5G 5 g 13.10 mp: 45–47 °C (CH2)5CH3 – Br 90145-50G 50 g 50.00 96662-5G 5 g 13.10 References 96662-50G 50 g 50.00 1. Bradaric, C. J.; Downard, A.; Kennedy, C.; Robertson A. J.; Zhou, Trihexyltetradecylphosphonium chloride, purum 8 Y. Green Chem. 2003, 5, 143 (CH ) CH C32H68ClP 2 5 3 + FW: 519.31 H3C(H2C)5 P (CH2)13CH3 mp: -70 °C (CH2)5CH3 Cl– [258864-54-9] 89744-5G 5 g 13.10 89744-50G 50 g 50.00

Ionic MALDI Matrices—Improve Your Performance .] 4 The striking advantages of MALDI (matrix-assisted laser desorption/ .u x10 [a . 375 ns

te 1.2 In ionization)-MS for characterization of mainly large molecules result 757. from the embedding of sample in a chemical matrix that greatly 1.0

facilitates the production of intact gas-phase ions from large, non- 645 3 1046. 66 0.8

volatile, and thermally labile compounds, such as peptides, proteins, 1347. 626

or oligonucleotides. The matrix plays a key role in this technique by 1296. 0.6 8 absorbing the laser light energy and causing a small part of the target 87 1619.

substrate to vaporize. 0.4 30 .9 1758 The commonly used matrix substances offer highly effective ionization 0.2 and low vapor pressure. One of their main disadvantages is that

0.0 the analytes cannot be dispersed throughout the solid matrix in 800 1000 1200 1400 1600 1800 2000 m/z a homogeneous manner. The target substance as well as other c) Angiotensin II (M = 1046.5), S/N = 104, Res. (M/∆M) = 1218 components of the sample (impurities) typically segregate, resulting in heterogeneous preparations and limited reproducibility. Heterogeneity The graphs show a comparison of mass spectra using a) HCCA, of analyte distribution within the sample spots is a serious problem, b) HCCA butylamine matrix, and c) HCCA diethylamine matrix. The 1 especially for the use of MALDI-MS for quantitative determinations. ionic matrices show improved resolution. These matrices also show Liquid matrices would provide homogeneous preparations and other modified peak pattern compared to the standard matrix, which may advantages, but typically suffer from their volatility, which results be advantageous for analyzing complex mixtures of peptides. The in an altering, uncontrolled matrix. With low mass resolution, poor analyzed peptide mix contains: Bradykinin 1-7, [M+H]+ = 757.411; ionization efficiency, and high chemical background, they have Angiotensin II, [M+H]+ =1046.504; Angiotensin I, [M+H]+ = 1296.623; restricted use in UV-MALDI-MS. Substance P, [M+H]+ = 1347.673; Bombesin, [M+H]+ =1619.741; + Ionic matrix substances are a new class of matrices composed of organic Renin-Substrate, [M+H] =1758.832. acids (classical matrices, others turned out to be unsuitable) and organic Ionic Matrices: Features and Benefits bases. Ionic matrices, especially the low-melting ones, provide several striking advantages. These matrix systems have excellent solubilizing • Improved Resolving Power Ionic MALDI Matrices properties compared to other commonly used matrices. They allow • Reproducibility a homogeneous sample preparation with a thin Ionic Liquid layer having negligible vapour pressure.2 This leads to facilitated qualitative • High Signal-to-Noise Ratio and quantitative measurements compared to classical matrices. • Suitable for Quantification It has been shown that ionic matrices yield a very homogeneous drop, so that performance of a single shot is much more reproducible and α-Cyano-4-hydroxycinnamic acid Diethylamine salt, 8 search for a “hot spot” is not required. Ionic matrices are specially puriss. p.a., matrix substance for MALDI-MS, ≥99% HPLC 3 suitable for qualitative and quantitative analyses of small molecules. - C10H7NO3 · C4H11N OO Sigma-Aldrich offers ionic matrices with the highest purity: α-cyano- FW: 262.30 4-hydroxycinnamic acid diethyl amine (HCCA diethylamine, [355011-52-8] CN H3CN CH3 Prod. # 55341) and α-cyano-4-hydroxycinnamic acid butyl amine + H2 (HCCA butylamine, Prod. # 67336). The use of these highly purified matrices may result in high signal-to-noise ratios and, especially, OH improved resolution. 55341-100MG 100 mg 9.80 .] 4 .u x10 [a . 629 55341-1G 1 g 31.30 ns te 552 In 1046. 390 1347. 757. 1.25 55341-10X10MG 10 × 10 mg 44.10

1.00 α-Cyano-4-hydroxycinnamic acid Butylamine salt, 8 241

635 puriss. p.a., matrix substance for MALDI-MS, ≥99% HPLC 1296. 1619.

0.75 C10H7NO3 · C4H11N OO- 1 73 FW: 262.30 0.50 1758. [355011-53-9] CN + H3CNH3 0.25

OH 0.00 800 1000 1200 1400 1600 1800 2000

m/z a) Angiotensin II (M = 1046.5); S/N = 74; Res. (M/∆M) = 341 67336-100MG 100 mg 9.80

.] 67336-1G 1 g 31.30 .u [a . 367 ns 8000 te 757. In 67336-10X10MG 10 × 10 mg 9.80 284 1045. 6000 5 References 92 346. 1 1. Garden, R. W.; Swedler, J. V. Anal. Chem. 2000, 72, 30. 303 1295. 2

4000 43

1619. 2. Armstrong, D. W.; Zhang, L.-K.; He, L.; Gross, M. L. Anal. Chem. 90 .6

1758 2001, 73, 3679.

2000 3. Zabet-Moghaddam, M.; Heinzle, E.; Tholey, A. Rapid Commun. Mass Spectrom. 2004, 18, 141.

0 800 1000 1200 1400 1600 1800 2000

m/z b) Angiotensin II (M = 1046.5), S/N = 63, Res. (M/∆M) = 764

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 17

Task-Speciﬁc Ionic Liquids

Roland St. Kalb and Michael J. Kotschan, proionic Production of Ionic Substances GmbH, Leoben, Austria. Task-Specific Ionic Liquids (TSILs) for the selective liquid/liquid extraction of heavy metals from aqueous systems were first published by Robin D. Rogers et al. in the year 2001.1 Functionalized imidazolium cations with thioether, urea, or thiourea derivatized side chains act as metal – ligating moieties, whereas the PF6 anions provide the desired water immiscibility (Figure 1). Nernst distribution ratios were reported for Cd2+ and Hg2+ to be ≤380.

S Figure 3: Extraction of Copper N N N N PF6 H H Phase separation sometimes can last a long period of time because of the relative high viscosity of TOMATS of 1500 mPa.s at 20 °C. Figure 1: Thiourea derivatized Ionic Liquid This drawback can be overcome by either adding some percent of a water-immiscible organic solvent like ethyl acetate or dichloromethane These Ionic Liquids were the first to contain specific functionalities to (decreasing the viscosity down to hundred mPa.s), or by heating. enable well defined chemical properties and therefore undoubtedly be called “designer solvents.” Phase separation can be optimized using a centrifuge and adding some sodium sulfate to the aqueous phase before shaking. If the aqueous However, these pioneering Ionic Liquids show some major drawbacks: phase still looks turbid, it can be filtered through a common membrane the hexafluorophosphate anion is known to be quite unstable toward filter (µm pore size). hydrolysis and produces toxic and corrosive HF or fluorides. The toxicity of the imidazolium cation is difficult to be estimated; an expensive Characterization of TOMATS toxicological study is risky. The disposal of these fluorous compounds is Appearance: olive green, viscous liquid expensive and problematic. The synthesis at larger scale is complicated; starting materials are expensive. Solubility: • Soluble in alcohols, ethyl acetate, THF, acetonitrile, acetone, dichloromethane, DMSO Trioctylmethylammonium thiosalicylate (TOMATS): A Novel, • Insoluble in water, hexane Task-Specific Ionic Liquids Task-Specific High Performance, Ionic Liquid for the Extraction of Heavy Nernst distribution coefficients:1 Cd2+ >1500; Cu2+ >3000; Metals from Aqueous Solutions Pb2+, Hg2+ >5000 20 To overcome the aforementioned drawbacks—especially in consideration Refractive index: nD = 1.5185 of a possible industrial application at larger scales—and to enhance the Leaching into aqueous phase: <0.5% performance, proionic Production of Ionic Substances GmbH developed Density, Viscosity: a new Ionic Liquid in their laboratories: Trioctylmethylammonium thiosalicylate (“TOMATS,” Prod. # 08354, Figure 2). TOMATS 100% TOMATS 95% (5% ethyl acetate) T [°C] d [g/cm3] η [mPa.s] d [g/cm3] η [mPa.s]

C8H17 20 0.9556 1.500 0.9534 509 CO2 N 40 0.9445 352 0.9424 158 H3C C8H17 C8H17 SH 60 0.9325 119 0.9300 63 80 0.9213 50 0.9185 30 Figure 2: TOMATS TOMATS contains no fluorine and is absolutely stable to any hydrolysis. Methyltrioctylammonium thiosalicylate, purum 8 It therefore does not release HF or fluorides, is not corrosive, and OO- C32H59NO2S (CH2)7CH3 + is much easier to dispose. The toxicity of the cation is known from FW: 521.88 H3C N (CH2)7CH3 SH common compounds like trioctylammonium chloride (a phase-transfer m.p.: <10 °C (CH2)7CH3 catalyst). The toxicity of the anion is known from thiosalicylic acid and its salts; they are found to be irritants. The distribution coefficients of 08354-1G 1 g 101.70 heavy metals typically show values in the range of 1500 to more than 08354-5G 5 g 279.80 5000, which may be explained by the chelating effect of the ortho- positioned carboxylate group additional to the known formation of Other Task-Specific Ionic Liquids metal-thiolates. The synthesis of TOMATS is simple and can be done at industrial scales. Recently, zwitterionic, sulfonic acid-functionalized Ionic Liquids have been used as alternatives to conventional acids in acid-catalyzed Application of TOMATS reactions.2 Sigma-Aldrich now offers several Task Specific Ionic Liquids Figure 3 shows the extraction of copper out of a blue-colored for this application. aqueous Cu2+-tetramine phase (left test tube). After addition of the TOMATS Ionic Liquid and before shaking, nice diffusion zones 4-(3-Butyl-1-imidazolio)-1-butanesulfonic acid triflate 8

SO3H can be seen (middle test tube), showing a copper-free, uncolored C12H21F3N2O6S2 region and a dark copper-containing upper region. After shaking FW: 410.43 N+ - and waiting for the separation of the phases, all the copper is [439937-63-0] F3CSO3 N extracted into the upper phase, forming an organic, dark-colored (CH2)3CH3 copper compound (right test tube). 19597-5G 5 g 212.60 19597-50G 50 g 584.70

4-(3-Butyl-1-imidazolio)-1-butanesulfonate 8 3-(Triphenylphosphonio)propane-1-sulfonate 8

SO - C11H20N2O3S 3 C21H21O3PS FW: 260.35 FW: 384.43 N+ [439937-61-8] [116154-22-4] P+ N - SO3 (CH2)3CH3

51131-5G 5 g 198.90 51131-50G 50 g 547.10 53166-5G 5 g 143.00 53166-50G 50 g 393.30 3-(Triphenylphosphonio)propane-1-sulfonic acid 8 tosylate References

C H O PS - 28 29 6 2 SO3 1. Aqueous phase with 5 to 50 ppm metal, 1:1 extraction. Visser, FW: 556.63 A. E.; Swatloski, R. P.; Reichert, W. M.; Rogers, R. D.; Mayton, R.; + [439937-65-2] P Sheff, S.; Wierzbicki, A.; Davis Jr., J. H. Chem. Commun. 2001, 135.

SO H CH 3 3 2. (a) Cole, A. C.; Jensen, J. L.; Ntai, I.; Tran, K. L. T; Weaver, K. J.; Forbes, D. C.; Davis, Jr., J. H. J. Am. Chem. Soc. 2002, 124, 07349-5G 5 g 109.80 5962–5963. (b) Gu, Y.; Shi, F.; Deng, Y. Catalysis Communications 07349-50G 50 g 302.00 2003, 4, 597–601.

Ionic Liquids Imidazolium-Based Ionic Liquids

1-Allyl-3-methylimidazolium chloride 8 1-Butyl-1-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)- 8 Imidazolium-Based CH3 imidazolium hexafluorophosphate, purum, ≥97% NMR C7H11ClN2 N+ - (CF2)5CF3 FW: 158.63 Cl C15H16F19N2P mp: 55 °C N FW: 616.24 N+ – [65039-10-3] mp: 120–121 °C N PF6 Task-Specific Ionic Liquids/ Task-Specific [313475-52-4]

43961-5G 5 g 72.70 H3C 43961-50G 50 g 218.20 94049-1G 1 g 52.10 1-Benzyl-3-methylimidazolium chloride 8 94049-5G 5 g 208.10 C H ClN CH3 11 13 2 N+ FW: 208.69 1-Butyl-2,3-dimethylimidazolium chloride, ≥97% AT 8 N Cl- CH3 mp: 70 °C C9H17ClN2 +N – [36443-80-8] FW: 188.70 Cl CH mp: 89 °C N 3 [98892-75-2] 49914-5G 5 g 63.30 CH3 49914-50G 50 g 189.90 19122-5G 5 g 26.60 1-Benzyl-3-methylimidazolium hexafluorophosphate 8 19122-50G 50 g 116.30 C H F N P CH3 11 13 6 2 N+ FW: 318.20 1-Butyl-2,3-dimethylimidazolium chloride, 8 PF - mp: 136 °C N 6 purum, ≥97% AT

CH3 [433337-11-2] C9H17ClN2 +N – FW: 188.70 Cl CH mp: 89 °C N 3 39447-5G 5 g 84.20 [98892-75-2] 39447-50G 50 g 231.60 CH3

1-Benzyl-3-methylimidazolium tetrafluoroborate 8 78194-5G 5 g 28.60 CH3 C11H13BF4N2 N+ 78194-50G 50 g 125.00 FW: 260.04 N BF - mp: 77 °C 4 1-Butyl-2,3-dimethylimidazolium hexafluoro- 8 [500996-04-3] phosphate, purum, ≥97% T CH3 C9H17F6N2P N+ FW: 298.21 N CH3 – 40819-5G 5 g 84.20 [227617-70-1] PF6 40819-50G 50 g 231.60 CH3 70869-5G 5 g 48.30 70869-50G 50 g 219.20

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 19

1-Butyl-2,3-dimethylimidazolium tetrafluoroborate 8 1-Butyl-3-methylimidazolium trifluoromethane- 8 purum, ≥98% T sulfonate, purum, ≥95% NMR

CH3 CH C9H17BF4N2 C9H15F3N2O3S 3 O N+ +N – FW: 240.05 FW: 288.29 F3CS O N CH3 N mp: 37 °C – mp: 13 °C BF4 O [402846-78-0] [174899-66-2]

CH3 CH3

70863-5G 5 g 19.10 76420-5G 5 g 52.10 70863-50G 50 g 72.10 76420-25G 25 g 208.10

1-Butyl-3-methylimidazolium 2-(2-methoxyethoxy)- 1-Ethyl-2,3-dimethylimidazolium chloride, 8 ethyl sulfate, purum, ≥95% T purum, ≥97% T

CH3 C13H26N2O6S CH3 C7H13ClN2 + N+ N Cl–

FW: 338.42 O FW: 160.64 CH3 N – N OS O(CH2CH2O)2CH3 mp: 181 °C O [92507-97-6] CH3

CH3 78151-5G 5 g 59.50 67421-5G 5 g 36.20 67421-50G 50 g 216.40 1-Ethyl-3-methylimidazolium bromide, purum, ≥97% T C H BrN CH3 6 11 2 N+ 1-Butyl-3-methylimidazolium bromide, purum, > 97% T FW: 191.07 Br- Ionic Liquids N C H BrN CH3 mp: 53 °C 8 15 2 + FW: 219.12 N Br- [65039-08-9] H3C N mp: 77 °C Imidazolium-Based [85100-77-2] H3C 89483-5G 5 g 30.60 95137-5G 5 g 40.00 89483-50G 50 g 126.50 95137-50G 50 g 74.10 1-Ethyl-3-methylimidazolium chloride, purum, 1-Butyl-3-methylimidazolium chloride, purum, ≥95% AT Ionic solvent, ≥97% AT

CH3 CH3 C8H15ClN2 C6H11ClN2 + N+ N Cl- FW: 174.67 Cl- FW: 146.62 mp: 41 °C N mp: 89 °C N [79917-90-1] [65039-09-0] H3C

H3C 72924-5G 5 g 35.40 72924-50G 50 g 204.60 94128-5G 5 g 25.40 94128-50G 50 g 70.60 1-Ethyl-3-methylimidazolium hexafluorophosphate 94128-250G 250 g 300.00 purum, ≥97% CE

CH C6H11F6N2P 3 1-Butyl-3-methylimidazolium methyl sulfate, purum, ≥97% NMR N+ – FW: 256.13 PF6 CH C9H18N2O4S 3 mp: 62 °C N N+ FW: 250.32 CH3 H CO [155371-19-0] N 3 O mp: 25 °C S [401788-98-5] O O- 46093-1G 1 g 30.80

H3C 46093-5G 5 g 113.10 46093-50G 50 g 296.40 83086-5G 5 g 162.20 1-Ethyl-3-methylimidazolium methyl sulfate, ≥99% 8 83086-50G 50 g 450.50 CH3 C7H14N2O4S N+ 1-Butyl-3-methylimidazolium tetrafluoroborate, purum, ≥97% T FW: 222.26 H3CO O N S O [516474-01-4] O- C8H15BF4N2 CH3 + H3C N – FW: 226.02 BF4 mp: -71 °C N 18086-5G 5 g 46.20 [174501-65-6] 18086-50G 50 g 138.70 H3C

91508-5G 5 g 61.50 91508-50G 50 g 170.80 91508-250G 250 g 678.60

1-Ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-Methyl-3-octylimidazolium chloride, purum, ≥97% AT purum, ≥98% T C12H23ClN2 CH3 + CH3 N C7H11F3N2O3S FW: 230.78 N+ F C Cl- 3 O N FW: 260.23 S mp: <0 °C O mp: -9 °C N O- [64697-40-1] (CH2)7CH3

[145022-44-2] CH3 95803-5G 5 g 30.80 04367-1ML 1 mL 42.90 95803-50G 50 g 85.50 04367-5ML 5 mL 157.10 04367-25ML 25 mL 471.40 1-Methyl-3-octylimidazolium trifluoromethane- 8 sulfonate, ≥97% T

1-Hexyl-3-methylimidazolium chloride, purum, ≥97% AT (CH2)7CH3 C13H23F3N2O3S CH N+ C H ClN 3 FW: 344.39 F CSO – 10 19 2 N+ 3 3 [403842-84-2] N FW: 202.72 Cl- N CH3

mp: -75 °C (CH2)5CH3 [171058-17-6] 42471-5G 5 g 58.10 87929-5G 5 g 43.10 42471-25G 25 g 232.50 87929-50G 50 g 119.30 1-Methyl-3-octylimidazolium trifluoromethane- 8 1-Hexyl-3-methylimidazolium hexafluorophosphate, 8 sulfonate, purum, ≥97% T purum, 97% T (CH ) CH ≥ C13H23F3N2O3S 2 7 3 + CH N F C C H F N P 3 FW: 344.39 3 O 10 19 6 2 N+ – S Ionic Liquids PF 6 N O FW: 312.24 [403842-84-2] O- mp: -80 °C N CH3 (CH2)5CH3 [304680-35-1] 68902-5G 5 g 62.50

Imidazolium-Based 89320-5G 5 g 65.00 68902-25G 25 g 250.00 89320-50G 50 g 259.70 1,2,3-Trimethylimidazolium trifluoromethane- 8 1-Hexyl-3-methylimidazolium trifluoromethane- 8 sulfonate, ≥98.5%

sulfonate, 95% T CH3 ≥ C7H11F3N2O3S N+ F3C (CH2)5CH3 FW: 260.23 O C12H21F3N2O3S S N CH3 O N+ O- FW: 330.37 F CSO – 3 3 CH3 mp: <30 °C N [460345-16-8] CH3 05942-5G 5 g 246.60 49980-5G 5 g 67.90 05942-50G 50 g 678.20 49980-25G 25 g 271.40 1-Butyl-3-methylimidazolium dicyanamide, ≥99% 8 1-Hexyl-3-methylimidazolium trifluoromethane- 8 C10H15N5 CH3 sulfonate, purum, ≥95% T N+ FW: 205.26 CN - (CH2)5CH3 mp: -6 °C N N C12H21F3N2O3S + CN N – [448245-52-1] FW: 330.37 F3CSO3 [460345-16-8] N H3C CH3 67476-5G 5 g 67.90 55220-5G 5 g 202.30 67476-25G 25 g 271.40 55220-50G 50 g 556.20

1-Methyl-3-(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro- 8 1-Butyl-3-methylimidazolium nitrate, purum, ≥98.5% 8 CH octyl)imidazolium hexafluorophosphate, purum, C8H15N3O3 3 + ≥97% NMR N – FW: 201.22 NO3 (CF ) CF [179075-88-8] N C12H10F19N2P 2 5 3 FW: 574.16 N+ - PF6 mp: 80 °C H3C [313475-50-2] N 07319-5G 5 g 177.70 44979-1G 1 g 85.70 07319-50G 50 g 488.70

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. US $ 21

Pyridinium-Based Ionic Liquids

1-Butylpyridinium bromide, ≥99% 8 1-Butyl-4-methylpyridinium chloride, 8 purum, ≥97% AT C9H14BrN + CH3 FW: 216.12 N Br– C10H16ClN mp: 105 °C FW: 185.69 + [874-80-6] mp: 158 °C N Cl– H3C [112400-86-9]

00285-5G 5 g 60.40 H3C 00285-50G 50 g 181.40 88482-5G 5 g 27.50 88482-50G 50 g 76.30 1-Butyl-4-methylpyridinium bromide, 8 purum, ≥98% AT 1-Butyl-4-methylpyridinium hexafluorophosphate, CH3 purum, 97% NMR C10H16BrN ≥ FW: 230.14 CH3 C10H16F6NP – mp: 135 °C N+ Br FW: 295.20 [65350-59-6] + – mp: 41 °C N PF6

H3C [401788-99-6]

H3C 94349-5G 5 g 27.40 88458-5G 5 g 91.30 94349-50G 50 g 91.00 88458-50G 50 g 253.10

Pyrrolidinium-Based Ionic Liquids Based Ionic Liquids Liquids/Pyrrolidinium-

1-Butyl-1-methylpyrrolidinium bis(trifluoromethyl- 8 1-Butyl-1-methylpyrrolidinium chloride, ≥99% 8 Pyridinium-Based Ionic sulfonyl)imide, ≥99% C9H20ClN Cl- C H F N O S FW: 177.71 N+ 11 20 6 2 4 2 CF CH3 + O 3 FW: 422.41 N S mp: 114 °C CH3 O -N O S [479500-35-1] CH O 3 CF3 CH3 07326-5G 5 g 67.70 38894-5G 5 g 111.60 07326-50G 50 g 203.10 38894-50G 50 g 306.90 1-Butyl-1-methylpyrrolidinium tetrafluoroborate, 8 1-Butyl-1-methylpyrrolidinium bromide, ≥99% 8 ≥99%

C9H20BrN Br- C9H20BF4N + FW: 222.17 N FW: 229.07 N+ CH3 CH3 – mp: >160 °C mp: 152 °C BF4 [93457-69-3] [345984-11-4] CH3 CH3

04275-5G 5 g 70.70 92409-5G 5 g 124.50 04275-50G 50 g 212.00 92409-50G 50 g 342.40

8 Safer, Amine-Stabilized BH3-THF Solutions for Hydroboration and Reduction

O o OH 65,039-0: 98%; 96.1%ee BH3-THF, 25 C CH3 CH3 65,041-2: 98%; 96.2%ee (R)-Me-CBS cat. Product Highlights: 1M in toluene 17,619-2: 97%; 90.3%ee (10 mol %) • Enhanced safety • Shipment for all pack sizes at OH room temperature providing 1 65,039-0: 90%; 93:7 (1:2) greater cost savings 1. BH3-THF + 65,041-2: 93%; 94:6 (1:2) 2. H2O2 • Excellent reactivity and selectivity 17,619-2: 92%; 94:6 (1:2) vs. BH3-THF (17,619-2; NaBH4- 2 OH stabilized)

8 65,039-0 BH3THF, 1.0M solution in THF, 1,2,2,6,6-Pentamethylpiperidine (PMP)-stabilized 8 65,041-2 BH3THF, 1.0M solution in THF, N-Isopropyl-N-methyl-tert-butylamine (NIMBA)-stabilized

17,619-2 BH3THF, 1.0M solution in THF, NaBH4-stabilized

Ammonium-Based Ionic Liquids

Tetrabutylammonium benzoate, purum, ≥98% NT Tetrabutylammonium bromide, puriss., ≥99% AT C H NO OO- C H BrN 23 41 2 (CH2)3CH3 16 36 (CH2)3CH3 + + - FW: 363.58 H3C(H2C)3 N (CH2)3CH3 FW: 322.37 H3C(H2C)3 N (CH2)3CH3 Br

mp: 64–67 °C (CH2)3CH3 mp: 102–106 °C (CH2)3CH3 [18819-89-1] [1643-19-2] 86850-5G 5 g 115.90 86860-25G 25 g 17.70 86850-25G 25 g 420.60 86860-100G 100 g 39.70 86860-500G 500 g 167.40 Tetrabutylammonium methanesulfonate, purum, ≥97% T

C17H39NO3S (CH2)3CH3 O + - Tetrabutylammonium bromide, purum, ≥98% AT FW: 337.56 H3C(H2C)3 N (CH2)3CH3 O S CH3 O mp: 78–80 °C (CH2)3CH3 C H BrN 16 36 (CH2)3CH3

+ - [65411-49-6] FW: 322.37 H3C(H2C)3 N (CH2)3CH3 Br 86877-10G 10 g 41.60 mp: 102–106 °C (CH2)3CH3 86877-50G 50 g 159.40 [1643-19-2] 86861-50G 50 g 14.40 Tetrabutylammonium nonafluorobutanesulfonate, 86861-250G 250 g 55.50 purum, ≥98% T 86861-1KG 1 kg 200.90

C20H36F9NO3S (CH2)3CH3 O

Ionic Liquids + - Tetrabutylammonium chloride, purum, ≥97% AT FW: 541.56 H3C(H2C)3 N (CH2)3CH3 F3C(F2C)2F2COS (CH ) CH O mp: 50–53 °C 2 3 3 C16H36ClN (CH2)3CH3 + - [108427-52-7] FW: 277.92 H3C(H2C)3 N (CH2)3CH3 Cl (CH2)3CH3 Ammonium-Based 86909-5G 5 g 61.90 [1112-67-0] 86909-25G 25 g 233.20 86870-25G 25 g 51.30 86870-100G 100 g 177.80 Tetrabutylammonium heptadecafluorooctanesulfonate 86870-500G 500 g 679.20 technical, ≥90 % T Tetraethylammonium trifluoroacetate, purum, ≥98% NT C24H36F17NO3S (CH2)3CH3 O + - H C(H C) N (CH ) CH F3C(F2C)6F2COS FW: 741.59 3 2 3 2 3 3 C10H20F3NO2 CH CH O 2 3 O (CH2)3CH3 + mp: <5 °C FW: 243.27 H3CH2C N CH2CH3 - OCF3 [111873-33-7] mp: 74–76 °C CH2CH3 86911-5ML 5 mL 127.80 [30093-29-9] 86911-25ML 25 mL 505.50 86647-5G 5 g 83.40 86647-25G 25 g 330.00 Tetrahexylammonium tetrafluoroborate, purum, ≥97% T Tetraheptylammonium bromide, purum, ≥99% AT C24H52BF4N (CH2)5CH3 + - H3C(H2C)5 N (CH2)5CH3 BF4 FW: 441.48 C28H60BrN (CH2)6CH3 (CH2)5CH3 + - mp: 90–92 °C FW: 490.69 H3C(H2C)6 N (CH2)6CH3 Br

[15553-50-1] mp: 89–91 °C (CH2)6CH3 87315-10G 10 g 58.00 [4368-51-8] 87315-50G 50 g 243.60 87301-10G 10 g 41.60 87301-50G 50 g 140.10 Tetraoctylammonium chloride, purum, ≥97% AT Tetraheptylammonium chloride, purum, ≥98% AT C32H68ClN (CH2)7CH3 + - FW: 502.34 H3C(H2C)7 N (CH2)7CH3 Cl C H ClN 28 60 (CH2)6CH3 (CH2)7CH3 + - mp: 50–54 °C FW: 446.24 H3C(H2C)6 N (CH2)6CH3 Cl

[3125-07-3] mp: 38–41 °C (CH2)6CH3 87991-5G 5 g 121.90 [10247-90-2] 87991-25G 25 g 481.20 87292-1G 1 g 36.80 87292-5G 5 g 144.50 Tetrapentylammonium thiocyanate, purum, ≥99% AT C H N S Tetrahexylammonium bromide, purum, ≥99% AT 21 44 2 (CH2)4CH3 + - FW: 356.65 H3C(H2C)4 N (CH2)4CH3 SCN C24H52BrN (CH2)5CH3 + - mp: 46–49 °C (CH2)4CH3 FW: 434.58 H3C(H2C)5 N (CH2)5CH3 Br

[3475-60-3] mp: 97 °C (CH2)5CH3 88009-5G 5 g 47.70 [4328-13-6] 88009-25G 25 g 188.10 87302-10G 10 g 30.90 87302-50G 50 g 131.10

TO ORDER: Contact your local Sigma-Aldrich office (see back cover),

sigma-aldrich.com call 1-800-325-3010 (USA), or visit sigma-aldrich.com. [ °C 54–57 mp: 430.62 FW: C Tetrabutylphosphonium [ °C 96–99 mp: 346.24 FW: C Tetrabutylphosphoniumpurum, tetrafluoroborate, [ °C 59–62 mp: 354.53 FW: C Tetrabutylphosphoniumpurum, methanesulfonate, Phosphonium-Based IonicLiquids [ °C 95–98 mp: 546.79 FW: C Tetraoctylammoniumpurum, bromide, [ °C 99–101 mp: 481.58 FW: C Tetrahexylammoniumpuriss., iodide, 116237-97-9 1813-60-1 98342-59-7 14866-33-2 2138-24-1 86933-25G 8693 86932-50G 8693 86929-25G 8692 88000-50G 8800 87307-50G 8730 23 16 17 32 24 H H H H H 43 36 39 68 52 3 2 9 0 7 O BF O BrN IN -5G -10G -10G -5G -10G 3 3 4 PS PS P from Sigma-Aldrich for greater cost savings. technologies, as well as information onthe latest promotion You will also receive technical notes on enabling synthesis issue, youwillreceive themostupdatedinformationonnovelreagents for: Sigma-Aldrich introduces each ournewmonthlyelectronic newsletterforchemicalsynthesis.With ] ] ] ] ] Accelerate Your Research withChemNews! Please visit p -toluenesulfonate, purum, -toluenesulfonate, · IonicLiquids · BuildingBlocks Along withnewselectionsof: · OxidationandReduction · C–C/C–XBondFormation · Catalysis · AsymmetricSynthesis sigma-aldrich.com/chem ≥ 99% AT99% H ≥ H 3 98% AT98% C(H 3 C(H H 25 g 25 g 50 g 25 g 50 g 10 g 50 g 10 H 3 2 5 g 5 g 5 g 5 C(H H C) 3 2 C(H 3 C) C(H 3 2 3 C) (CH (CH 2 P C) 2 (CH (CH 3 + C) P 7 + 2 2 (CH 5 (CH (CH ) ) P 2 2 3 3 (CH (CH (CH ) ) + CH CH N (CH (CH 3 3 N + CH CH 2 2 2 ≥ (CH + ) ) ) ≥ 3 3 2 3 2 2 3 3 (CH 97% T 97% ) CH ) ) CH CH 2 2 ≥ 3 3 (CH 3 7 7 98% NT 98% ) ) CH CH CH 2 5 5 98% NT 98% ) CH CH 3 3 3 2 3 ) CH 2 236.10 213.50 173.80 141.90 197.30 3 3 3 7 ) CH 3 3 5 59.80 47.90 43.90 38.00 46.60 CH H 3 O O 3 3 C 3 O CH S BF S - Br O 4 O O 3 I - - - - [ °C 102–104 mp: 339.33 FW: C Tetrabutylphosphoniumpurum, bromide, [ °C 99–102 mp: 378.47 FW: C Tetrapentylammoniumpurum, bromide, [ °C 57–62 mp: 507.65 FW: C Tributylhexadecylphosphoniumpurum, bromide, [ °C 62–66 mp: 294.88 FW: C Tetrabutylphosphoniumpurum, chloride, 3115-68-2 866-97-7 14937-45-2 2304-30-5 88001-100G 8800 52353-100G 5235 86919-50G 8691 86917-500G 8691 16 20 28 16 H H H H new 36 44 60 36 1 3 9 7 BrP NBr BrP ClP -25G -25G -10G -100G

]

s ] ] toview thelatestissue. ] ≥ 100 g 100 100 g 100 g 500 g 100 ≥ H 99% AT99% ≥ 25 g 25 25 g 25 g 50 g 10 H H 3 H 97% AT97% C(H 98% AT98% 3 3 3 C(H C(H C(H 2 C) 2 2 2 C) C) C) 15 3 3 4 (CH ≥ (CH (CH (CH (CH (CH (CH P (CH N P P + 95% AT95% + + + 2 (CH 2 2 2 2 2 2 2 ) (CH (CH (CH ) ) ) ) ) ) 3 ) 3 3 4 4 3 3 3 CH CH CH CH CH CH CH CH 2 2 2 2 ) 3 ) ) ) 3 229.40 199.70 225.40 3 3 3 3 3 3 3 3 4 3 CH CH CH CH 73.70 61.20 48.80 97.90 29.40 US $ US 3 3 3 3 Br Cl Br Br - - - -

Order: 1.800.325.3010 Technical Service: 1.800.231.8327 23 Ammonium-Based Ionic Liquids/Phosphonium- Based Ionic Liquids Argentina France Japan Singapore SIGMA-ALDRICH DE ARGENTINA, S.A. SIGMA-ALDRICH CHIMIE S.à.r.l. SIGMA-ALDRICH JAPAN K.K. SIGMA-ALDRICH PTE. LTD. Tel: 54 11 4556 1472 Tel appel gratuit: 0800 211 408 Tokyo Tel: 03 5796 7300 Tel: 65-6779-1200 Fax: 54 11 4552 1698 Fax appel gratuit: 0800 031 052 Tokyo Fax: 03 5796 7315 Fax: 65-6779-1822

Australia Germany Korea South Africa SIGMA-ALDRICH PTY., LIMITED SIGMA-ALDRICH CHEMIE GmbH SIGMA-ALDRICH KOREA SIGMA-ALDRICH Free Tel: 1800 800 097 Free Tel: 0800-51 55 000 Tel: 031-329-9000 SOUTH AFRICA (PTY) LTD. Free Fax: 1800 800 096 Free Fax: 0800-649 00 00 Fax: 031-329-9090 Free Tel: 0800 1100 75 Tel: 612 9841 0555 Free Fax: 0800 1100 79 Fax: 612 9841 0500 Greece Malaysia Tel: 27 11 979 1188 SIGMA-ALDRICH (O.M.) LTD SIGMA-ALDRICH (M) SDN. BHD Fax: 27 11 979 1119 Austria Tel: 30 210 9948010 Tel: 603-56353321 SIGMA-ALDRICH HANDELS GmbH Fax: 30 210 9943831 Fax: 603-56354116 Spain Tel: 43 1 605 81 10 SIGMA-ALDRICH QUÍMICA S.A. Fax: 43 1 605 81 20 Hungary Mexico Free Tel: 900 101376 SIGMA-ALDRICH Kft SIGMA-ALDRICH QUÍMICA, S.A. de C.V. Free Fax: 900 102028 Belgium Tel: 06-1-235-9054 Free Tel: 01-800-007-5300 SIGMA-ALDRICH NV/SA. Tel: 91 661 99 77 Fax: 06-1-269-6470 Free Fax: 01-800-712-9920 Fax: 91 661 96 42 Free Tel: 0800-14747 Ingyenes zöld telefon: 06-80-355-355 Free Fax: 0800-14745 Ingyenes zöld fax: 06-80-344-344 The Netherlands Tel: 03 899 13 01 Sweden SIGMA-ALDRICH CHEMIE BV Fax: 03 899 13 11 SIGMA-ALDRICH SWEDEN AB Tel Gratis: 0800-0229088 India Tel: 020-350510 SIGMA-ALDRICH CHEMICALS Fax Gratis: 0800-0229089 Brazil Fax: 020-352522 PRIVATE LIMITED Tel: 078-6205411 SIGMA-ALDRICH BRASIL LTDA. Outside Sweden Tel: +46 8 7424200 Telephone Fax: 078-6205421 Tel: 55 11 3732-3100 Outside Sweden Fax: +46 8 7424243 Bangalore: 91-80-5112-7272 Fax: 55 11 3733-5151 New Delhi: 91-11-5165 4255 New Zealand Switzerland Mumbai: 91-22-2570 2364 SIGMA-ALDRICH PTY., LIMITED Canada FLUKA CHEMIE GmbH Hyderabad: 91-40-5584 5488 Free Tel: 0800 936 666 SIGMA-ALDRICH CANADA LTD. Swiss Free Call: 0800 80 00 80 Fax Free Fax: 0800 937 777 Free Tel: 800-565-1400 Tel: +41 81 755 2828 Bangalore: 91-80-5112-7473 Free Fax: 800-265-3858 Fax: +41 81 755 2815 Tel: 905-829-9500 New Delhi: 91-11-5165 4266 Norway Fax: 905-829-9292 Mumbai: 91-22-2579 7589 SIGMA-ALDRICH NORWAY AS Hyderabad: 91-40-5584 5466 Tel: 23 17 60 60 United Kingdom SIGMA-ALDRICH COMPANY LTD. China Fax: 23 17 60 50 Ireland Free Tel: 0800 717181 SIGMA-ALDRICH CHINA INC. Free Fax: 0800 378785 Tel: 86-21-6386 2766 SIGMA-ALDRICH IRELAND LTD. Poland Tel: 01747 833000 Fax: 86-21-6386 3966 Free Tel: 1800 200 888 SIGMA-ALDRICH Sp. z o.o. Free Fax: 1800 600 222 Tel: +4861 829 01 00 Fax: 01747 833313 SAFC (UK): 01202 712305 Czech Republic Tel: 353 1 4041900 Fax: +4861 829 01 20 SIGMA-ALDRICH s.r.o. Fax: 353 1 4041910 Tel: +420 246 003 200 Portugal United States Fax: +420 246 003 291 Israel SIGMA-ALDRICH QUÍMICA, S.A. SIGMA-ALDRICH SIGMA-ALDRICH ISRAEL LTD. Free Tel: 800 202180 P.O. Box 14508 Denmark Free Tel: 1-800-70-2222 Free Fax: 800 202178 St. Louis, Missouri 63178 SIGMA-ALDRICH DENMARK A/S Tel: 08-948-4100 Tel: 21 9242555 Toll-free: 800-325-3010 Tel: 43 56 59 10 Fax: 08-948-4200 Fax: 21 9242610 Call Collect: 314-771-5750 Fax: 43 56 59 05 Toll-Free Fax: 800-325-5052 Italy Russia Tel: 314-771-5765 Finland SIGMA-ALDRICH S.r.l. SIGMA-ALDRICH RUSSIA Fax: 314-771-5757 SIGMA-ALDRICH FINLAND Telefono: 02 33417310 OOO SAF-LAB Tel: (09) 350 9250 Fax: 02 38010737 Tel: +7 (095) 975-1917/3321 Internet: Fax: (09) 350 92555 Numero Verde: 800-827018 Fax: +7 (095) 975-4792 sigma-aldrich.com

PRESORTED STANDARD U.S. POSTAGE P.O. Box 355 PAID Milwaukee, WI 53201 SIGMA-ALDRICH CORPORATION USA

Return Service Requested

Order/Customer Service 1-800-325-3010 • Fax 1-800-325-5052 Technical Service 1-800-325-5832 • sigma-aldrich.com/techservice

Development/Bulk Manufacturing Inquiries 1-800-244-1173 World Headquarters • 3050 Spruce St., St. Louis, MO 63103 • (314) 771-5765

We are committed to the success of our Customers, Employees and Shareholders through leadership in Life Science, High Technology and Service. The SIGMA-ALDRICH Family

©2005 Sigma-Aldrich Co. All rights reserved. SIGMA, , SAFC, , SIGMA-ALDRICH, , ISOTEC, ALDRICH, , FLUKA, , and SUPELCO are trademarks belonging to Sigma-Aldrich Co. and its affiliate Sigma-Aldrich Biotechnology IAX LP. Riedel-de Haën®: trademark under license from Riedel-de Haën GmbH. Sigma products are sold through Sigma-Aldrich, Inc. Sigma-Aldrich, Inc. warrants that its products conform to the 02159-040517 information contained in this and other Sigma-Aldrich publications. Purchaser must determine the suitability of the product(s) for their particular use. Additional terms and conditions may apply. 0065 Please see reverse side of the invoice or packing slip.