Imidazole and imidazolium cations with exceptional alkaline stability

Abstract

A polymer is provided that can maintain good conductivity and stability in a fuel cell device. [Solution] Formula (III'): TIFF2023052139000084.tif54158 and membranes and devices comprising the polymers. Also provided are methods for making the compounds and polymers of the invention.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62 / 147,388, filed April 14, 2015, the entire contents of which are incorporated herein by reference. STATEMENT OF GOVERNMENT RIGHTS

[0002] This invention was made with Government support under Grant No. DE-SC0001086 awarded by the U.S. Department of Energy. The U.S. Government has certain rights in this invention. [Background technology]

[0003] As the demand for clean and efficient energy increases, fuel cells have emerged as an attractive electrochemical conversion device due to their high energy density and ability to produce energy more cleanly and efficiently compared to traditional systems such as internal combustion engines. Proton exchange membrane fuel cells (PEMFCs) are used in many commercial applications. However, widespread production of PEMFCs is limited by the cost and durability of the materials used to fabricate them, such as the platinum electrodes and electrolyte membrane.

[0004] Given the drawbacks associated with widespread production of PEMFCs, attention has shifted to alkaline fuel cells (AFCs), which transport hydroxide ions in an electrolyte solution under alkaline conditions. At higher pH, oxygen reduction is easier and lower overpotentials are required, which allows the use of non-precious metal catalysts in AFCs. In fact, the earliest examples of commercially available fuel cells used aqueous potassium hydroxide as the electrolyte medium to facilitate anion conduction. Unfortunately, the performance of these early fuel cells was compromised by exposure to carbon dioxide, a common component of the feed gas that reacts with hydroxide to produce carbonate. To overcome this problem, alkaline anion exchange membranes (AAEMs) can be used in alkaline fuel cells. AAEMs, which generally consist of organic cations covalently bonded to a polymer backbone, are used to prevent the formation of mobile salts and retain the conductive organic cation / hydroxide species.

[0005] Tetraalkylammonium cations have been added to various polymeric structures to create AAEMs, including perfluorinated membranes, aromatic polysulfones, poly(arylene ethers), poly(arylene ether ketones), polyphenylenes, polystyrenes, and various aliphatic backbones. However, current ammonium cations (e.g., the ubiquitous benzyltrimethylammonium (BTMA) cation) degrade rapidly under fuel cell operating conditions, limiting their utility and making the improvement of AAEM stability a key priority. Thus, moieties that enhance stability under fuel cell operating conditions are needed.

[0006] Although certain aspects of the prior art have been discussed to facilitate understanding of the present disclosure, applicants do not reject these technical aspects and believe that the claimed invention may encompass one or more of the aspects of the prior art discussed herein.

[0007] Where any document, act or article of knowledge is referenced or discussed in this specification, such reference or discussion is not an admission that the document, act or article of knowledge, or any combination thereof, was published, known to the public, or part of the general knowledge at the priority date, or constitutes prior art under any provision of applicable law; i.e., known as being relevant to any attempt to solve any problem to which this specification pertains. Summary of the Invention

[0008] Briefly, the present invention satisfies the need for moieties that enhance stability under fuel cell operating conditions. The present invention may address one or more of the problems and shortcomings of the technology discussed above. However, it is believed that the present invention may prove useful in addressing other problems and shortcomings in many technical fields. Thus, the present invention should not necessarily be construed as being limited to addressing any of the specific problems or shortcomings discussed herein.

[0009] Certain embodiments of the presently disclosed imidazoles and imidazolium cations, polymers incorporating imidazolium cations, and articles and related methods comprising them have several features, no single one of which is responsible for their desirable attributes. Without limiting the scope of the compounds, polymers, articles, and methods of the present invention, as defined by the following description and claims, their more prominent features will now be briefly discussed. After considering this discussion, and particularly after reading the section of this specification entitled "Detailed Description of the Invention," one will appreciate how the features of the various embodiments disclosed herein provide many advantages over the current state of the art. These advantages include, but are not limited to, providing imidazoles and imidazolium cations (and polymers incorporating imidazolium cations) that are easy to manufacture and / or work into compounds into polymers, are resistant to degradation by nucleophilic or basic attack by hydroxides or methoxides, and / or can maintain good electrical conductivity and stability in fuel cell devices.

[0010] Imidazole compounds and / or imidazolium cations that are stable under basic conditions are of great importance in many applications, including, but not limited to, organic catalysis, solar cell electrolytes, phase transfer catalysis, as carbon material precursors, in OLEDs (organic light emitting diodes), ionic liquids and as cocatalysts. In general, the compounds and polymers of the present invention are useful wherever base-stable organic cations and their precursors are needed or beneficial. Additionally, the imidazole and imidazolium cation embodiments of the present invention are useful in a number of applications, including, but not limited to, ring-opening metathesis (ROMP), controlled radical polymerization and polymerization of functionalized α-olefins. The imidazole compounds can be easily incorporated into polymer structures using any of the polymerization techniques. The imidazole compounds may also be attached to preformed polymers by reacting with electrophilic sites present in the polymer. Polymers with base-stable cations added to the backbone are in demand for applications such as fuel cell membrane electrolytes, electrolysis, gas separation, desalination, anion exchange resins, nuclear waste remediation, and stimuli-responsive materials. The polymers of the present invention may be useful wherever polymers containing base-stable cations are currently used.

[0011] In one aspect, the present invention provides a compound represented by formula (I) or (II): [ka] [however, R 1 is C2~C 16 Hydrocarbyl, wherein C2 to C 16 One carbon atom of the hydrocarbyl may be optionally substituted with O; R 2 is 0 to 3 substituents R independently selected from C1 to C3 alkyl 6 Replaced with is phenyl; R 3 is C2~C 16 Selected from hydrocarbyl; R 4 and R 5 is C1~C 16 R individually or jointly selected from hydrocarbyl 4 and R 5 together with the carbon atoms to which they are attached form a ring selected from benzene, cyclooctene, and norbornene; and X - is the counter ion. The present invention provides a compound represented by the formula:

[0012] In a second aspect, the present invention provides a compound of formula (III'): [ka] [however, R 2’ is C1-C6 alkyl and R 2 Selected from; R 2 is 0 to 3 substituents R independently selected from C1 to C3 alkyl 6 is a phenyl substituted with; R 3’ is hydrogen, methyl and R 3 Selected from; R 3 is C2~C 16 Selected from hydrocarbyl; R 4 and R 5 is C1~C 16 R individually or jointly selected from hydrocarbyl 4 and R 5 together with the carbon atoms to which they are attached form a ring selected from benzene, cyclooctene, and norbornene; X - is the counterion, The wavy lines indicate points of attachment to adjacent polymer repeat units; W is a direct bond or C1-C 10 is a hydrocarbyl; Y is a direct bond or C1-C 10 is hydrocarbyl; and Z is a direct bond or C1-C 13 Hydrocarbyl, and the C1-C 13 One carbon atom of the hydrocarbyl may be optionally substituted with O; and the total number of carbon atoms of W, Y and Z is 1 to 15. The present invention provides a polymer comprising a plurality of imidazolium-containing repeat units of the formula:

[0013] In a third aspect, the present invention provides a membrane comprising a polymer according to the second aspect of the invention.

[0014] In a fourth aspect, the present invention provides a device comprising a polymer according to the second aspect of the invention or a membrane according to the third aspect of the invention.

[0015] In a fifth aspect, the present invention provides a method for determining the stability of a compound, the method comprising: Preparing a solution of the compound in basic methanol-d3 (KOH / CD3OH); storing the solution; and The amount of compound remaining is determined by comparing it with an internal standard. 1 Analyzing the solutions by H NMR spectroscopy Contains:

[0016] These and other features and advantages of the present invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the appended claims.

[0017] Aspects and specific features, advantages, and details of the present invention are more fully described below with reference to the non-limiting embodiments described herein. Descriptions of well-known materials, manufacturing tools, processing techniques, and the like are omitted so as not to unnecessarily obscure the details of the invention. However, it should be understood that the detailed description and specific examples, while illustrating embodiments of the present invention, are given by way of illustration only and are not limiting. Various substitutions, modifications, additions, and / or arrangements within the spirit and / or scope of the concepts of the present invention will be apparent to those skilled in the art from this disclosure.

[0018] The present invention provides imidazole and imidazolium compounds (including imidazolium monomers), as well as polymers that include imidazolium functional groups (including residues of the imidazolium compounds of the present invention). It also provides methods for producing the compounds and polymers. The compounds of the present invention are used as precursors of the polymers of the present invention, and as predictors of the stability of the polymers of the present invention, which may be used, for example, in membranes (e.g., fuel cell alkaline anion exchange membranes). The polymers are also useful in other applications, such as electrolysis, gas separation, desalination, and as stimuli-responsive materials.

[0019] Unless otherwise indicated by the context, the formula (I), (II), (III′) or (III) discussed in the present invention (e.g., R 1 ~R 6 , X, W, Y and Z) extend to references to all other sub-formula subgroups, preferred aspects, embodiments and examples defined herein (including the uses, methods and other aspects of the invention).

[0020] The prefix "C" used herein x- C y " or "C x~y " (where x and y are integers) refers to the number of carbon atoms in a given group. Thus, for example, C 1- C6 alkyl (or C 1~6 The alkyl group contains 1 to 6 carbon atoms.

[0021] The term "hydrocarbyl" is a generic term that includes aliphatic, alicyclic and aromatic groups having an all-carbon backbone, unless otherwise stated. Hydrocarbon refers to any substituent that consists of hydrogen and carbon as the only elemental components. In some cases, one or more of the carbon atoms that make up the carbon backbone may be replaced with a specific atom, as defined herein. Examples of hydrocarbyl groups include alkyl, cycloalkyl, cycloalkenyl, aryl, alkenyl, alkynyl, cycloalkylalkyl, cycloalkenylalkyl, and carbocyclic aralkyl, aralkenyl and aralkynyl groups (as well as alkylaralkyl, etc.). Such groups may be unsubstituted or, where referred to, may be substituted with one or more of the substituents defined herein. The following examples and preferred embodiments apply to each of the hydrocarbyl or hydrocarbyl-containing substituents referred to in the various definitions of the substituents of the compounds and polymers discussed herein, unless the context indicates otherwise.

[0022] The number of carbon atoms in a given hydrocarbyl group is generally indicated by the prefix "C x- C y ” ("C x~y" can also be used). For example, the C1-C 16 Hydrocarbyl groups (i.e., C1, C2, C3, C4, C5, C6, C7, C8, C9, C 10 , C 11 , C 12 , C 13 , C 14 , C 15 or C 16 Hydrocarbyl groups) and their subgroups (e.g., C2 to C 16 Within the subset of hydrocarbyl, specific examples include C 1~10 Hydrocarbyl group, C 2-10 Hide locarbyl group, C 1~7 Hydrocarbyl groups (e.g., C 1~4 Hydrocarbyl groups (e.g., C 1~3 Hydrocarbyl group or C 1~2 Hydrocarbyl group), and C 2~7 Hydrocarbyl groups (e.g., C 2~6 Hydrocarbyl groups (e.g., C 2~4 Hydrocarbyl group or C 2~3 Hydrocarbyl groups).

[0023] The term "alkyl" as used herein as a group or part of a group refers to a straight or branched chain saturated hydrocarbon group containing the specified number of carbon atoms. Examples of such groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, or hexyl, etc.

[0024] An "alkenyl" group refers to a straight-chain or branched unsaturated hydrocarbon group containing at least one carbon-carbon double bond.

[0025] An "alkynyl" group refers to a straight-chain or branched unsaturated hydrocarbon group containing at least one carbon-carbon triple bond.

[0026] The term "aryl" as used herein refers to carbocyclyl aromatic groups such as phenyl, naphthyl, indenyl and tetrahydronaphthyl groups.

[0027] The term "cycloalkyl" as used herein refers to a saturated monocyclic hydrocarbon ring having the specified number of carbon atoms. Examples of such groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, or cyclooctyl, and the like.

[0028] The term "cycloalkenyl," as used herein, refers to a monocyclic hydrocarbon ring having a carbon-carbon double bond.

[0029] Examples of cycloalkylalkyl, cycloalkenylalkyl, carbocyclic aralkyl, aralkenyl and aralkynyl groups include phenethyl, benzyl, styryl, phenylethynyl, cyclohexylmethyl, cyclopentylmethyl, cyclobutylmethyl, cyclopropylmethyl and cyclopentenylmethyl groups.

[0030] In one aspect, the present invention provides a compound according to formula (I) or (II): [ka] [however, R 1 is C2~C 16 Hydrocarbyl, wherein C2 to C 16 One carbon atom of the hydrocarbyl may be optionally substituted with O; R 2 is 0 to 3 substituents R independently selected from C1 to C3 alkyl 6 is a phenyl substituted with; R 3 is C2~C 16 Selected from hydrocarbyl; R 4 and R 5 is C1~C 16 Hydrocarbyls may be individually or jointly selected from R 4and R 5 together with the carbon atoms to which they are attached form a ring selected from benzene, cyclooctene, and norbornene; and X - is the counter ion. The present invention provides a compound represented by the formula:

[0031] As shown above, the compounds of formula (I) are imidazole compounds (R 1 is absent), and the compound of formula (II) is a positively charged imidazolium cation.

[0032] R 1 is C2~C 16 Hydrocarbyl (i.e., C2, C3, C4, C5, C6, C7, C8, C9, C 10 , C 11 , C 12 , C 13 , C 14 , C 15 or C 16 Hydrocarbyl), C2 to C 16 One carbon atom of the hydrocarbyl (and the hydrogen atoms bonded to that carbon atom) may be replaced with oxygen (O).

[0033] In some embodiments, R 1 is C2~C 16 hydrocarbyl (no carbon atom is replaced by O).

[0034] In some embodiments, R 1 The nitrogen at position 1 of the imidazole ring and R 1 C2-C where one carbon atom not at the bonding point is replaced with O 16 hydrocarbyl (or any subgroup thereof).

[0035] In some embodiments, R 1 is C2~C 12 C, in which one carbon atom of the hydrocarbyl is optionally substituted with O 2- C 12is selected from hydrocarbyl.

[0036] In some embodiments, R 1 is C2~C 10 C, in which one carbon atom of the hydrocarbyl is optionally substituted with O 2- C 10 is selected from hydrocarbyl.

[0037] In some embodiments, R 1 is a C2-C7 hydrocarbyl in which one carbon atom may be optionally substituted with O 2- Selected from C7 hydrocarbyls.

[0038] In some embodiments, R 1 is selected from C2 to C4 hydrocarbyls, one carbon atom of which may be optionally substituted with O.

[0039] In some embodiments, R 1 is a C2-C8 alkyl group in which one carbon atom may be optionally substituted with O; 2- C alkyl.

[0040] In some embodiments, R 1 is a C2-C6 alkyl group in which one carbon atom may be optionally substituted with O 2- C6 alkyl.

[0041] In some embodiments, R 1 is selected from ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl and hexyl, one carbon atom of which is optionally substituted with O.

[0042] In some embodiments, R 1 is an alkylaralkyl group, one carbon atom of which may be optionally replaced with O. For example, in some embodiments, R1 is H(CH2) p -(Ph) q -(CH2) r - * (In the formula, * represents the point of attachment to the nitrogen at position 1 of the imidazole, p is 1 to 6, q is 0 or 1; r is 1 to 6, and R 1 The total number of carbon atoms in is 2 to 16, and one carbon atom may be optionally replaced by O. As used herein, the abbreviation "Ph" stands for phenyl.

[0043] In some embodiments, R 1 is H(CH2) p -(Ph) q -(CH2) r - * (In the formula, * represents the point of attachment to the nitrogen at position 1 of the imidazole, p is 1 to 6, q is 0 or 1; r is 1 to 6, and R 1 The total number of carbon atoms in (CH2) is 2 to 16, p wherein one carbon atom may be optionally replaced by O.

[0044] In some embodiments, R 1 but, [ka] [however, * represents the point of attachment to the nitrogen atom at position 1 of the imidazolium ring; m is 0 or 1; and n is 1 to 8; And the sum of m+n does not exceed 8. These embodiments (and R 1 Other embodiments having other strained cycloolefin rings therein) find particular application in ring-opening metathesis polymerization (ROMP), which is one technique that can be used to incorporate imidazolium cations into polymers, as discussed below.

[0045] In some embodiments, R 1 is benzyl.

[0046] In some embodiments, R 1 is not benzyl.

[0047] R 2 is 0 to 3 substituents R 6 phenyl substituted with (i.e., R 6 Each R 6 (when present) are individually selected from C1-C3 alkyl.

[0048] The applicant is R 2 found that imidazolium cationic compounds containing phenyl groups have better base stability than those with alkyl groups. This observation was confirmed by Lin et al., Chem. Mater., 25, 1858 (2013) (where the alkyl substituent is This contrasts with the trend observed for the phenyl group, which shows improved stability compared to the phenyl group.

[0049] In some embodiments, R 2 is unsubstituted phenyl.

[0050] In some embodiments, R 2 is R 6 is substituted 1 to 3 times with each R 6 are individually selected from methyl, ethyl, n-propyl and isopropyl.

[0051] In some embodiments, R 2 is the formula (R 2a ): [ka] [however, [ka] represents the point of attachment to the imidazole or imidazolium ring, R6a , R 6b and R 6c are individually selected from hydrogen and C1-C3 alkyl.

[0052] In some embodiments, R 6a , R 6b and R 6c At least two of are individually selected from methyl and isopropyl.

[0053] R 3 is C2~C 16 Hydrocarbyl (i.e., C2, C3, C4, C5, C6, C7, C8, C9, C 10 , C 11 , C 12 , C 13 , C 14 , C 15 or C 16 hydrocarbyl).

[0054] In some embodiments, R 3 is C2~C 12 is selected from hydrocarbyl.

[0055] In some embodiments, R 3 is C2~C 10 is selected from hydrocarbyl.

[0056] In some embodiments, R 3 is selected from C2 to C7 hydrocarbyls.

[0057] In some embodiments, R 3 is selected from C2 to C4 hydrocarbyl.

[0058] In some embodiments, R 3 is selected from C2 to C8 alkyl.

[0059] In some embodiments, R 3 is selected from C2 to C6 alkyl.

[0060] In some embodiments, R 3 is selected from ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl and hexyl.

[0061] In some embodiments, R 3 is benzyl.

[0062] In some embodiments, R 3 is not benzyl.

[0063] R 4 and R 5 are C1~C 16 R selected from hydrocarbyl or combined 4 and R 5 together with the carbon atom to which they are attached form a ring selected from benzene, cyclooctene, and norbornene.

[0064] In some embodiments, R 4 and R 5 are C1 to C 12 is selected from hydrocarbyl.

[0065] In some embodiments, R 4 and R 5 are C1 to C 10 is selected from hydrocarbyl.

[0066] In some embodiments, R 4 and R 5 are individually selected from C1 to C7 hydrocarbyls.

[0067] In some embodiments, R 4 and R 5 are individually selected from C1 to C4 hydrocarbyls.

[0068] In some embodiments, R 4 and R5 are individually selected from C1 to C8 alkyl.

[0069] In some embodiments, R 4 and R 5 are individually selected from C1 to C6 alkyl.

[0070] In some embodiments, R 4 and R 5 are individually selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and hexyl.

[0071] In some embodiments, R 4 and R 5 are individually selected from C1-C6 alkyl and phenyl optionally substituted with C1-C3 alkyl.

[0072] X - is the counter ion.

[0073] In some embodiments, X - is selected from hydroxides, halides, bicarbonates, carbonates, nitrates, cyanides, carboxylates and alkoxides.

[0074] In certain embodiments, X - is a hydroxide.

[0075] In some embodiments, X - is fluoride (F - ), chloride (Cl - ), bromide (Br - ) and iodide (I - ) is a halide selected from

[0076] In some embodiments, R 1 ~R 6 The total number of carbon atoms in is greater than or equal to 10.

[0077] In some embodiments, R 1 ~R 6 wherein the total number of carbon atoms in is 10 to 60 (i.e., 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, or 60 carbon atoms), including any and all ranges and subranges within this range (e.g., 10 to 50, 15 to 45, 18 to 45, etc.).

[0078] In some embodiments, the present invention provides a method for the preparation of a compound comprising the steps of: 3 C2~C 12 or R 1 and R 3 are independent and C2~C 12 The compound of formula (II) is provided, wherein the compound is selected from the group consisting of hydrocarbyls.

[0079] In some embodiments, the present invention provides a method for the preparation of 3 is selected from C2 to C7 hydrocarbyl, or 1 and R 3 is independently selected from C2 to C7 hydrocarbyl.

[0080] In some embodiments, the present invention provides a method for the preparation of a compound comprising the steps of: 3 is selected from C2-C4 alkyl and benzyl, or 1 and and R 3 is independently selected from C2-C4 alkyl and and benzyl.

[0081] In some embodiments, the present invention provides a method for the preparation of 4 and R 5 are individually selected from phenyl and C1-C3 alkyl.

[0082] In some embodiments, the present invention provides a method for the preparation of a compound comprising the steps of: 2 is the part R shown above 2a In a compound where and this compound is: Compounds of formula (I) (wherein R 3 is n-butyl; R 6a and R 6c is methyl and R 6b is hydrogen; R 4 and R 5 are independently selected from phenyl and methyl; or A compound of formula (II) 1 and R 3 are n-butyl; R 6a and R 6c is methyl and R 6b is hydrogen; R 4 and R 5 are independently selected from phenyl and methyl.

[0083] In some embodiments, the present invention provides a compound of formula (II), e.g., a compound represented by formula (IIA), (IIB) or (IIC): [ka] The compound is a monomer of the formula:

[0084] In some embodiments, the present invention provides compounds with improved alkaline stability. As discussed above, imidazole compounds and / or imidazolium cations (and polymers containing such compounds) that are stable under basic conditions are of great importance for a variety of applications.

[0085] In some embodiments, the present invention provides compounds having an alkaline stability with 75%-100% of the cation remaining after 30 days in 5M KOH / CD3OH at 80°C (75%-100% includes any and all ranges within this range, as well as subranges within this range, such as 80%-100%, 85%-100%, 90%-100%, 95%-100%, etc.). The stability is determined by preparing a solution of the cation in basic methanol-d3(KOH / CD3OH) and storing it in a flame-sealed NMR tube at 80°C. At uniform time intervals, the solution is immersed in 100 mL of 100 mL of 10% NaCl. H The amount of cation remaining is analyzed by NMR spectroscopy relative to an internal standard. The use of CD3OH eliminates hydrogen / deuterium exchange processes that result in a reduction of the cation signal (not related to decomposition) and obscure the new product signal. Key aspects of the cation decomposition pathway are revealed in this new protocol, which facilitates the design of novel imidazolium species with strategically placed substituents to prevent decomposition.

[0086] In some embodiments, the invention provides compounds having an alkaline stability of 80% or more (e.g., 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99%) of residual cations after 30 days in 5M KOH / CD3OH at 80° C.

[0087] In some embodiments, the present invention provides a method for the preparation of a compound of formula (I): [ka] (However, R 2 ~R 6 and X - is defined as above.) The present invention provides a compound of the formula:

[0088] As discussed below, compounds of formula (I) are useful as intermediates in the preparation of polymers according to the second aspect of the invention (see below).

[0089] In some embodiments, the present invention provides a method for the preparation of a compound of formula (II): [ka] (However, R 1 ~R 6 and X - is defined as above.) The present invention provides a compound of the formula:

[0090] In addition to being useful for incorporation of their residues into polymers according to the second aspect of the invention (discussed below), compounds of formula (II) are also useful as predictive tools for assessing the stability of polymers according to the second aspect of the invention, and are useful in a variety of other applications such as organocatalysis, solar cell electrolytes, phase transfer catalysis, and carbon material precursors.

[0091] Imidazole compounds of formula (I) are a class of organic compounds that are easy to synthesize, since they can be prepared by modular routes with easily modified substituents and can be readily converted to imidazolium cations (e.g., synthesis of formula (II) by alkylation).

[0092] Methods for synthesizing imidazole and imidazolium compounds are well known in the art. In some embodiments, compounds of formula (I) or formula (II) can be prepared according to the following scheme 1: [ka] It is synthesized as shown in

[0093] In a second aspect, the present invention provides a compound of formula (III'): [ka] [however, R 2’ is C1-C6 alkyl and R 2 Selected from; R 2 is 0 to 3 substituents R independently selected from C1 to C3 alkyl 6is a phenyl substituted with; R 3’ is hydrogen, methyl and R 3 Selected from; R 3 is C2~C 16 Selected from hydrocarbyl; R 4 and R 5 is C1~C 16 R individually or jointly selected from hydrocarbyl 4 and R 5 together with the carbon atoms to which they are attached form a ring selected from benzene, cyclooctene, and norbornene; X - is the counterion, The wavy lines indicate points of attachment to adjacent polymer repeat units; W is a direct bond or C1-C 10 is a hydrocarbyl; Y is a direct bond or C1-C 10 is hydrocarbyl; and Z is a direct bond or C1-C 13 Hydrocarbyl, and the C1-C 13 One carbon atom of the hydrocarbyl may be optionally substituted with O; and the total number of carbon atoms of W, Y and Z is 1 to 15. The present invention provides a polymer comprising a plurality of imidazolium-containing repeating units (IRUs) represented by the formula:

[0094] The polymers described herein contain imidazolium moieties. These imidazolium cations provide improved stability under fuel cell operating conditions compared to other (e.g., ammonium) cations, which degrade rapidly under fuel cell operating conditions, limiting their usefulness and making the improvement of AAEM stability a key priority, making the polymers particularly desirable for use as alkaline anion exchange membranes (AAEMs). Fuel cells are constructed by methods well known in the art that allow the membranes described herein to be substituted for anion exchange membranes in the art.

[0095] In the case of the polymer according to the second aspect of the invention, R 2 ~R 6 is as defined above with respect to the various embodiments of the first aspect of the invention.

[0096] W is a direct bond or C1-C 10 It is a hydrocarbyl.

[0097] In some embodiments, W is a direct bond or (C 10 ) alkylene (i.e., C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 As will be appreciated by those of skill in the art, alkylene refers to a divalent alkyl group; an example is -CH2CH2CH2CH2CH2CH2CH2CH2-.

[0098] Y is a direct bond or C 1- C 10 It is a hydrocarbyl.

[0099] In some embodiments, Y is a direct bond or (C 10 ) alkylene (i.e., C1, C2, C3, C4, C5, C6, C7, C8, C9 or C 10 alkylene).

[0100] In some embodiments, W is (CH) 1-5 and Y is (CH2) 1-5 It is.

[0101] Z is a direct bond or C1-C 13 Hydrocarbyl and C1-C 13 One carbon atom of the hydrocarbyl may be optionally substituted with O.

[0102] In some embodiments, Z comprises a phenylene moiety. Phenylene is a divalent phenyl. [ka] Refers to...

[0103] In some embodiments, the polymer of the present invention comprises a compound of formula (I) or (II) or a residue thereof.

[0104] In some embodiments, the polymer of the present invention of formula (III') has formula (III): [ka] It is a polymer

[0105] In some embodiments, the polymer of the present invention has formula (IIIA'): [ka] [however, m is 0 or 1; and Z 1a is C1~C 13 It is a hydrocarbyl. The compound includes a plurality of imidazolium-containing repeat units of the formula:

[0106] In some embodiments, the polymer of the present invention has formula (IIIA): [ka] [however, m is 0 or 1; and Z 1a is C1~C 13 It is a hydrocarbyl. The imidazolium-containing repeating unit comprises:

[0107] In some embodiments of polymers comprising imidazolium-containing repeat units of formula (IIIA') or (IIIA), m is 0.

[0108] In some embodiments of polymers comprising imidazolium-containing repeat units of formula (IIIA') or (IIIA), m is 1.

[0109] In some embodiments of the polymer comprising an imidazolium-containing repeat unit of formula (IIIA') or (IIIA), Z 1a is C1~C 10 It is a hydrocarbyl.

[0110] In some embodiments of the polymer comprising an imidazolium-containing repeat unit of formula (IIIA') or (IIIA), Z 1a is a C1-C8 hydrocarbyl.

[0111] In some embodiments of the polymer comprising an imidazolium-containing repeat unit of formula (IIIA') or (IIIA), Z 1a Ga-(CH2) p -(Ph) q -(CH2) r -, and p is 1-6, q is 0 or 1; and r is 1-6. In some embodiments, p is 1-2, q is 0 or 1, and r is 1-2.

[0112] In some embodiments, the polymer of the present invention has formula (IIIB'): [ka] [however, m is 0 or 1; n is 1 to 8. The imidazolium-containing repeating unit is represented by the following formula:

[0113] In some embodiments, the polymer of the present invention has formula (IIIB): [ka] [however, m is 0 or 1; n is 1 to 8. The imidazolium-containing repeating unit is represented by the following formula:

[0114] In some embodiments, the polymer comprises a polyolefin or polystyrene backbone.

[0115] In some embodiments, the polymer of the present invention has formula (IIIC') or (IIIC): [ka] The imidazolium-containing repeating unit is represented by the following formula:

[0116] In some such embodiments, X - is a halide.

[0117] In some embodiments of the polymers of the present invention, the total of carbon atoms in W and Y is 1 or 3.

[0118] The polymers described herein may be cast or otherwise formed into membranes, as described below, which are useful, for example, in hydrogen generation devices, fuel cells, and water purification devices.

[0119] In some embodiments, the polymer comprises, in addition to the IRUs, a hydrocarbon repeating unit (HRU), and the polymer has the following structure: [ka] (wherein n' is 0.05 to 1.0 and represents the molar fraction of IRU in the polymer). The IRU and HRU units may be arranged randomly or consecutively. In some embodiments, n' is 0.1 to 0.4.

[0120] The polymer may be a random or block copolymer. Adjacent IRUs and HRUs or IRUs and IRUs or HRUs and HRUs may be linked by carbon-carbon single bonds or carbon-carbon double bonds, as shown below. In some embodiments, for example, when the polymer is used in an AAEM, at least some of the double bonds are reduced. In some embodiments, between 50 and 100% (e.g., 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100%) of the carbon-carbon double bonds are reduced to carbon-carbon single bonds.

[0121] The polymer may be crosslinked or non-crosslinked. In some embodiments, the polymer is not crosslinked. An example of one embodiment of an unsaturated non-crosslinked polymer is: [ka] is an imidazolium residue: [ka] As shown in.

[0122] An example of one embodiment of a saturated non-crosslinked polymer has Formula II: [ka] As shown in.

[0123] Polymer embodiments of the present invention can be synthesized by ring-opening metathesis polymerization (ROMP), which can be carried out using a transition metal (e.g., ruthenium-based) metathesis catalyst (e.g., second generation Grubbs-type catalyst). The process of ROMP polymerization is known in the art. For example, the method includes providing a strained ring monomer (or strained ring monomers) and a catalyst, such as a ruthenium-based alkene metathesis catalyst. The monomer(s) and catalyst are mixed, optionally in the presence of a solvent. The reaction mixture is heated under conditions such that a polymer is formed. A strained ring structure refers to a structure in which at least one bond angle in the molecule is tetrahedral (109.5°) optimal (sp 3 bond) or triangular planar structure (120°) (sp 2 bond) means that the ground state energy of a carbocycle is greater than that of a carbocycle with all normal bond angles.

[0124] In the case of ROMP, the imidazolim monomer (IM) from which the IRU is derived (some embodiments of which fall within the class of formula (II)) comprises at least one alkyl group capable of polymerization. The IM is a hydrocarbon having an alkene group. The IM can have multiple alkene moieties that can crosslink the polymer as a result of polymerization of two alkene moieties from two different IM units. For example, an IM and a monomer having multiple alkene functional groups can be copolymerized to provide a crosslinked polymer.

[0125] In a third aspect, the present invention provides a membrane comprising a polymer according to the second aspect of the invention.

[0126] In a fourth aspect, the present invention provides a device comprising a polymer according to the second aspect of the invention or a membrane according to the third aspect of the invention.

[0127] In some embodiments, the device is selected from a fuel cell, a hydrogen generator, a water purification device, and the like. In some embodiments, the device is a fuel cell. The fuel cell may further comprise an anode, a cathode, and a catalyst. In certain embodiments, the present invention provides a fuel cell operating under alkaline conditions comprising an alkaline anion exchange membrane (AAEM) comprising a polymer of formula (III') or (III).

[0128] In a fuel cell, an ion exchange membrane serves as an electrically conductive interface between the anode and cathode by being impermeable to gaseous and liquid fuels and transporting ions. It is desirable for an ion exchange membrane to have four properties:

[0129] (1) Low solubility in methanol – complete insolubility is ideal.

[0130] (2) Hydroxide conductivity of 1 mS / cm to 300 mS / cm - hydroxide conductivities of 1, 5, 10, 25, 50, 100, 150, 200 and 300 mS / cm are increasingly desired.

[0131] (3) mechanical properties such that membranes containing the ionomer do not tear or break under fuel cell operating conditions; and

[0132] (4) As little swelling and hydrogel formation as possible under alkaline fuel cell conditions. Ideally, swelling should be less than 20% of the original AAEM membrane thickness.

[0133] In some embodiments of the third aspect of the invention (relating to a membrane comprising a polymer according to the second aspect of the invention), the membrane is an AAEM comprising a polymer of the invention. The AAEM embodiments exhibit the desirable properties described above. In some embodiments, the AAEM comprising the polymeric material described herein has a thickness of 1 to 300 μm (e.g., 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 μm), including any and all ranges and subranges therein.

[0134] In a fifth aspect, the invention provides a method for determining the stability of a compound (e.g., an imidazolium cation) comprising preparing a solution of the compound in basic methanol-d3 (KOH / CD3OH); storing the solution (e.g., in a sealed NMR tube at 80° C.); and determining the amount of compound remaining by comparison to an internal standard. 1 and analyzing the solution by H NMR spectroscopy. The use of CD3OH eliminates hydrogen / deuterium exchange processes that cause a decrease in compound signal (not related to decomposition) and obscure new product signals. This embodiment of the method is also useful for elucidating aspects of compound (e.g., imidazolium cation) decomposition pathways and for designing new compounds. EXAMPLES

[0135] The following examples are presented to illustrate the present invention and are not intended to be limiting in any manner.

[0136] Methods and Equipment Flash chromatography was performed on silica gel (particle size 40-64 mm, 230-400 mesh) using mixtures of either ethyl acetate and hexane, diethyl ether and hexane, or dichloromethane and methanol as eluents. 1 H and 13C NMR spectra were recorded on a Varian INOVA 500 or 600 MHz instrument at 22 °C and showed residual solvent peaks (CD3OD or CD3OH); 3.31 ppm ( 1 H) and 49.00 ppm ( 13 C) or CDCl3; 7.26 ppm ( 1 H) and 77.16 ppm ( 13 The shifts relative to the cation shifts reported were reported for the cation shifts (C) and cation shifts (DART-HRMS). Analysis by high-resolution mass spectrometry (DART-HRMS) was performed using a Thermo Scientific Epitaxy Instrument equipped with an Ion Sense DART ion source. The analysis was performed on a Scientific Exactive Orbitrap MS system.

[0137] Solvent suppression procedure Quantitation of model compounds for stability studies 1 H NMR spectra were acquired in CD3OH to 1) prevent undesired hydrogen / deuterium exchange in model compounds and degradation products, and 2) improve the solubility of model compounds and degradation products. The -OH signal in CD3OH was suppressed by presaturation with a 2 s presaturation delay, and continuous wave irradiation with a decoupler field strength (γB1) of 113 Hz (corresponding to a saturation of 9). Spectra were acquired over a spectral width of -1 to 14 ppm, with a relaxation delay of 60 s and a nominal 90° excitation pulse. Sixteen scans were averaged for each analysis. NMR spectra were processed using MestReNova version 9.0.1-13254 (Mestrelab Research SL). Residual -OH signals were further suppressed by the signal suppression function of the software. Spectra were zero-filled to 256k complex points and an exponential window function of 0.2 Hz was applied before manual phase correction. Whittaker's smoother baseline correction was applied and linear correction was used for all integrations. NOTE: Residual signals between 5.5-7.0 ppm often originate from solvent suppression.

[0138] Chemicals Benzaldehyde, 2,6-dimethylbenzaldehyde, 2-methylpropionaldehyde, ethanal, 2,3-butanedione, diphenylethanedione, n-butylamine, 2M methylamine in methanol, 2M ethylamine in methanol, L-proline, benzyl bromide, ethyl iodide, n-butyl iodide, 2-iodopropane, 1-methylimidazole, and 1,2-dimethylimidazole were purchased from Aldrich and used as received. Benzylamine and methyl iodide were purchased from Alfa Aesar and used as received. Ammonium acetate, dichloromethane, ethyl acetate, and chloroform were purchased from Fischer and used as received. Trimethylamine (31-35% in ethanol) was purchased from Fluka and used as received. 3-(Trimethylsilyl)-1-propanesulfonic acid sodium salt and 1,2,4,5-tetramethylimidazole were purchased from TCI Chemicals and used as received. Methanol-d3 was purchased from Acros and used as received. Methanol-d4 and chloroform-d were purchased from Cambridge Isotope Laboratories. Methanol, hexane and acetonitrile were purchased from Macron and used as received. Tetrahydrofuran, magnesium sulfate and diethyl ether were purchased from JT Baker and used as received. Potassium hydroxide was purchased from Mallinck Purchased from rodt and used as received.

[0139] Synthesis procedure General Procedure A: Multicomponent synthesis of substituted imidazoles: The appropriate aldehyde, dione and primary amine were mixed with ammonium acetate and L-proline in methanol and stirred at 60° C. for 12 h. After cooling to 22° C., the solvent was removed under reduced pressure. The residue was dissolved in chloroform, washed with HO, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was further purified by recrystallization, flash column chromatography or a combination of both.

[0140] General procedure B: Quaternization of imidazoles with alkyl or benzyl halides: The appropriate imidazole precursor was dissolved in acetonitrile and the halide reagent was added with stirring. The mixture was stirred at 80° C. for 12 h. After cooling to room temperature, the solvent was removed under reduced pressure. The residue was dissolved in chloroform and purified by precipitation into ether, ethyl acetate, methanol or tetrahydrofuran. Repeated precipitation gave the pure product. Note: To obtain the salt without residual solvent, the powder was mixed with a small amount of dichloromethane and the solvent was removed under reduced pressure.

[0141] Synthesis of imidazole 1-Benzyl-2-(2,6-dimethylphenyl)-4,5-dimethyl-1H-imidazole (IM-3a) [ka] Following general procedure A, 2,6-dimethylbenzaldehyde (1.00 g, 7.45 mmol), 2,3-butanedione (0.65 ml, 7.5 mmol), benzylamine (0.81 ml, 7.5 mmol) and ammonium acetate (0.574 g, 7.45 mmol) were mixed with L-proline (0.136 g, 1.18 mmol) in methanol (30 ml). The residue was purified by flash column chromatography (2% methanol / dichloromethane) to give IM-3a (0.359 g, 17%) as an orange oil. 1 H NMR (600 MHz, CD3OD): δ 7.46 (t, J= 7.7 Hz, 1H), 7.34 - 7.27 (m, 3H), 7.23 (d, J= 7.7 Hz, 2H), 6.94 (dm, J= 7.6 Hz, 2H), 5.12 (s, 2H), 2.40 (s, 3H), 2.40 (s, 3H), 1.95 (s, 6H). 13 C NMR (126 MHz, CD3OD): δ 143.80, 140.52, 134.95, 133.52, 130.12, 129.74, 129.42, 128.5 0, 128.47, 127.29, 123.78, 50.05, 19.67, 9.31, 9.01. C 15 H 21 HRMS calculated for N2+ (M + H+) ( DART) m / z 291.18558, measured value 291.18515.

[0142] 1-Benzyl-4,5-dimethyl-2-phenyl-1H-imidazole (IM-3b) [ka] According to general procedure A, benzaldehyde (5.0 ml, 49 mmol), 2,3-butadiene Benzylamine (4.3 ml, 49 mmol), benzylamine (5.9 ml, 54 mmol) and ammonium acetate (3.78 g, 49.0 mmol) were mixed with L-proline (0.846 g, 7.35 mmol) in methanol (100 ml). The residue was purified by flash column chromatography (50% ethyl acetate / hexane). The product was recrystallized from acetonitrile to give IM-3b (2.54 g, 20%) as a pale yellow powder. 1 H NMR (500 MHz, CD3OD): δ 7.45 (m, 2H), 7.38 (m, 3H), 7.32 (t, J= 7.4 Hz, 2H), 7.30 - 7.24 (t, J= 7.4 Hz, 1H), 6.98 - 6.94 (d, J= 7.6 Hz , 2H), 5.19 (s, 2H), 2.20 (s, 3H), 2.05 (s, 3H). 13 C NMR (126 MHz, CD3OD): δ 147.56, 138. 54, 133.91, 131.73, 130.00, 129.96, 129.69 , 129.66, 128.57, 126.65, 125.57, 48.71, 12 .38, 8.98. C 18 H 19 N2+ (M + H + ) calculated for HRMS ( DART) m / z 263.15428, measured value 263.15349.

[0143] 1-Benzyl-2-isopropyl-4,5-dimethyl-1H-imidazole (IM-3c) [ka] According to general procedure A, 2-methylpropionaldehyde (5.2 ml, 57 mmol), 2,3-butanedione (5.0 ml, 57 mmol), benzylamine (6.2 ml, 57 mmol) and ammonium acetate (4.40 g, 57.0 mmol) were mixed with L-proline (0.984 g, 8.55 mmol) in methanol (100 ml). The residue was purified by flash column chromatography (1:10:90 triethylamine / methanol / dichloromethane). The product was recrystallized from acetonitrile at -20°C and sublimed to give IM-3c (0.841 g, 6.5%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.31 (t, J= 7.6 Hz, 2H), 7.25 (t, J= 7.4 Hz, 1H), 6.93 (d, J= 7.8 Hz, 2H ), 5.12 (s, 2H), 2.96 (hept, J= 6.9 Hz, 1H), 2.12 (s, 3H), 2.01 (s, 3H), 1.18 (d, J= 6.9 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 152.94, 138.84, 132.04, 129.88, 128.49, 126.74, 123 .08, 47.22, 27.17, 22.27, 12.14, 8.67. C 15 H 21 N2 + (M + H + ) HRMS (DART) m / z calculated for 229.1 6993, actual value 229.1705.

[0144] 1-Benzyl-2-(2,6-dimethylphenyl)-4,5-diphenyl-1H-imidazole (IM-4a) [ka] According to general procedure A, 2,6-dimethylbenzaldehyde (1.00 g, 7.45 mm ol), diphenylethanedione (1.57 g, 7.45 mmol), benzylamine (0.80 ml, 7.5 mmol) and ammonium acetate (0.574 g, 7.45 mmol) were mixed with L-proline (0.129 g, 1.12 mmol) in methanol (30 ml). The residue was purified by flash column chromatography (10% ethyl acetate / hexane). The product was recrystallized from acetonitrile to give IM-4a (0.787 g, 25%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.50 - 7.43 (m, 3H), 7.41 (m, 4H), 7.30 (t, J= 7.6 Hz, 1H), 7.18 (tm,J= 7.4 Hz, 2H), 7.16 - 7.10 (m, 4H), 7.06 (t, J= 7.7 Hz, 2H), 6.59 (d, J= 7.7 Hz, 2H), 4.83 (s, 2H), 2.02 (s, 6H). 13 C NMR (126 MHz, CDCl3): δ 146.54, 138.83 , 137.41, 136.34, 134.78, 131.47, 131.31, 130.54, 129.27, 129.04, 128.57,128.52,128. 12, 128.03, 127.49, 127.41, 127.38, 126.64 , 126.15, 47.76, 19.93. C 19 H 31 N2 + (M + ) Calculated HRMS (DART) m / z 415.21688, observed 415.21722.

[0145] 2-(2,6-dimethylphenyl)-1-methyl-4,5-diphenyl 1H-imidazo (IM2-4a) [ka] According to general procedure A, 2,6-dimethylbenzaldehyde (2.08 g, 15.5 mmol), diphenylethanedione (3.26 mg, 15.5 mmol), 2M methylamine in methanol (7.8 ml, 16 mmol) and ammonium acetate (1.19 g, 15.5 mmol) were mixed with L-proline (0.892 g, 7.75 mmol) in methanol (60 ml). The residue was purified by flash column chromatography (15% ethyl acetate / hexane). The product was recrystallized from acetonitrile to give IM2-4a (1.30 g, 25%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.53 - 7.45 (m, 3H), 7.41 (m, 4H), 7.33 ( t, J= 7.6 Hz, 1H), 7.24 - 7.16 (m, 4H), 7.16 - 7.12 (t, J= 7.3 Hz, 1H), 3.20 (s, 3H), 2.18 (s, 6H). 13 C NMR (126 MHz, CD3OD): δ 148.14, 140.11, 138.21, 135.51, 132.05, 132.04, 131.28, 130.98, 130.52, 130.21, 129.89, 129. 13, 128.58, 128.19, 127.60, 31.73,19.96. C 24 H 23 N2 + (M + H + ) HRMS (DART) m / z calculated for 339 .18558, actual value 339.18505.

[0146] 1-Methyl-2,4,5-triphenyl-1H-imidazole (IM-4b) [ka] Following general procedure A, benzaldehyde (2.5 ml, 25 mmol), diphenylethanedione (5.20 g, 24.7 mmol), 2M methylamine in methanol (12 ml, 25 mmol) and ammonium acetate (1.90 g, 24.7 mmol) were mixed with L-proline (0.427 g, 3.70 mmol) in methanol (100 ml). The residue was recrystallized in methanol to give IM-4b (2.88 g, 38%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.69 (dm, J= 7 .7 Hz, 2H), 7.51 (m, 2H), 7.49 - 7.40 (m, 4H), 7.37 (m, 4H), 7.20 - 7.14 (m, 2H), 7.14 - 7 .07 (tm, J= 7.6 Hz, 1H), 3.45 (s, 3H). 13 CNM R (126 MHz, CDCl3): δ 147.93, 137.78, 134.7 2, 131.26, 131.01, 130.92,130.52,129.11, 129.09, 128.79, 128.62 * , 128.13, 127.00, 12 6.35, 33.21. C 22 H 19 N2 + (M + H + ) HRM calculated for S(DART) m / z 311.15428, found 311.15334.

[0147] 1-Benzyl-2,4,5-triphenyl-1H-imidazole (IM2-4b) [ka] According to general procedure A, benzaldehyde (2.0 ml, 20 mmol), diphenylethanedione (4.10 g, 19.6 mmol), benzylamine (2.1 ml, 20 mmol) and ammonium acetate (1.50 g, 19.6 mmol) were mixed with L-proline (0.338 g, 2.94 mmol) in methanol (80 ml). The residue was purified by flash column chromatography (10% ethyl acetate / hexane to 50% ethyl acetate / hexane). The product was recrystallized in methanol at -20°C to give IM2-4b (1.84 g, 24%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.66 - 7.61 (m, 2H), 7.48 - 7.45 (m, 3H) , 7.45 - 7.41 (m, 2H), 7.41 - 7.31 (m, 3H), 7.26 - 7.23 (dm, J= 7.8 Hz, 2H),7.22- 7.11 (m, 6H), 6.73 (dm, J= 7.9 Hz, 2H), 5.17 (s, 2H). 13 C NMR (126 MHz, CDCl3): δ 148.11, 138.12, 137.58, 134.55, 131.10, 131.08, 131.02, 13 0.11, 129.09, 128.93, 128.83, 128.66, 128. 63, 128.61, 128.13, 127.39, 126.82, 126.40 , 126.04, 48.31. C 28 H 23 N2 + (M + H + ) calculated HRMS (DART) m / z 387.18558, observed 387.18430.

[0148] 1-Benzyl-2-isopropyl-4,5-diphenyl-1H-imidazole (IM-4c) [ka] According to general procedure A, 2-methylpropionaldehyde (2.5 ml, 28 mmol), diphenylethanedione (5.76 g, 27.4 mmol), benzylamine (3.0 ml, 27 mmol) and ammonium acetate (2.17 g, 27.4 mmol) were mixed with L-proline (0.473 g, 4.11 mmol) in methanol (100 ml). The residue was purified by flash column chromatography (1:10:90 triethylamine / ethyl acetate / hexanes) to give IM-4c (2.41 g, 25%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.39 - 7.31 (m, 5H), 7.28 (t, J= 7.4 Hz, 2H), 7.25 - 7.20 (m, 3H), 7.20 - 7.16 (tm, J= 7.7 Hz, 2H), 7.16-7.11 (tm, J= 7.4 Hz, 1H), 6.92 (d, J= 7.6 Hz, 2H), 5.11 (s, 2H), 3.05 (hept, J= 6.9 Hz, 1H ), 1.29 (d, J= 6.9 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 155.14, 138.82, 138.21, 135.76, 132.27, 132.02, 129.90 * , 129.80, 129.71, 12 8.99, 128.64, 128.55, 127.51, 126.89, 47.7 6, 27.69, 22.09. C 25 H 25 N2 + (M + H + ) calculated HRMS (DART) m / z 353.20123, observed 353.20105.

[0149] 1-Benzyl-2-methyl-4,5-diphenyl-1H-imidazole (IM-4d) [ka] According to general procedure A, ethanal (2.0 ml, 36 mmol), diphenylethanedione (7.48 mg, 35.6 mmol), benzylamine (4.3 ml, 36 mmol) and ammonium acetate (2.74 g, 35.6 mmol) were mixed with L-proline (0.615 g, 5.34 mmol) in methanol (30 ml). The residue was purified by flash column chromatography (1:20:80 triethylamine / ethyl acetate / hexane). The product was recrystallized from acetonitrile at -20°C to give IM-4d (0.652 g, 5.6%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.41 - 7.33 (m, 5H), 7.28 (tm, J= 7.6 Hz, 2H), 7.25 - 7.19 (m, 3H), 7.17 (tm, J= 7.4 Hz, 2H), 7.14 - 7.09 (tm, J= 7.3Hz, 1H), 6.92 - 6.89 (m, 2H), 5.05 (s, 2H), 2.37 (s, 3H). 1 3 C NMR (126 MHz, CD3OD): δ 146.63, 138.22, 137.45, 135.49, 132.19, 132.01, 130.61, 130 .01, 129.89 * , 129.09, 128.60, 128.06, 127. 50,127.00, 48.10, 13.16. C 23 H 21 N2 + (M + H + ) calculated HRMS (DART) m / z 325.16993, observed 325.1705.

[0150] 2-(2,6-dimethylphenyl)-1-ethyl-4,5-diphenyl-1H-imidazolidinate Zoll (IM-5a) [ka] According to general procedure A, 2,6-dimethylbenzaldehyde (1.00 g, 7.45 mmol), diphenylethanedione (1.57 g, 7.45 mmol), 2M ethylamine in methanol (7.5 ml, 15 mmol) and ammonium acetate (0.570 g, 7.45 mmol) were mixed with L-proline (0.128 g, 1.12 mmol) in methanol (30 ml). The residue was purified by flash column chromatography (10% ethyl acetate / hexane). The product was recrystallized from acetonitrile at -20°C to give IM -5a (0.411 g, 16%) was obtained as a white powder. 1 H NMR (600 MHz , CD3OD): δ 7.52 (m, 3H), 7.44 (d, J = 7.4 Hz , 2H), 7.38 (d, J= 7.4 Hz, 2H), 7.34 (t, J= 7 .7 Hz, 1H), 7.22 (d, J= 7.6 Hz, 2H), 7.18 (t, J= 7.3 Hz, 2H), 7.15-7.11 (m, 1H), 3.66 (q, J= 7.1 Hz, 2H), 2.22 (s, 6H), 0.91 (t, J = 7. 1 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 147.37, 139.99, 138.57, 135.47, 132.33, 132.22, 131.45, 130.97, 130.30, 130.00, 129.86, 129 .10, 128.73, 128.11, 127.54, 40.47, 20.19, 15.92. C 25 H 25 N2 + (M + H + ) calculated HRMS(DART) m / z 353.20123, observed 353.20028.

[0151] 1-n-Butyl-2,4,5-triphenyl-1H-imidazole (IM-6b) [ka] According to general procedure A, benzaldehyde (2.0 ml, 20 mmol), diphenylethanedione (4.54 g, 21.6 mmol), n-butylamine (2.1 ml, 22 mmol) and ammonium acetate (1.51 g, 19.6 mmol) were mixed with L-proline (0.260 g, 2.26 mmol) in methanol (80 ml). The residue was purified by flash column chromatography (10% ethyl acetate / hexane to 100% ethyl acetate). The product was recrystallized from acetonitrile to give IM-6b (6.39 g, 93%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.71 - 7.66 (d, J= 7.4 Hz, 2H), 7.58 - 7.45 (m,6 H), 7.44 - 7.36 (m, 4H), 7.21 - 7.16 (t, J= 7 .4 Hz, 2H), 7.16-7.11 (m, 1H), 4.00 - 3.93 ( m, 2H), 1.27 (p, J= 7.4 Hz, 2H), 0.93 (sext, J= 7.4 Hz, 2H), 0.56 (t, J= 7.4 Hz, 3H). 13 C NMR (126 MHz, CDCl3): δ 147.71, 137.73, 134. 71, 131.66, 131.63, 131.08, 129.70, 129.24 ,129.08,128.82, 128.64 * , 128.07, 126.85, 1 26.22, 44.55, 32.58, 19.49, 13.33. C 25 H 25 N2 + (M + H + ) calculated HRMS (DART) m / z 353.20123, observed 353.20124.

[0152] 1-n-Butyl-2-(2,6-dimethylphenyl)-4,5-dimethyl-1H-imidazole (IM-7a) [ka] Following general procedure A, 2,6-dimethylbenzaldehyde (2.00 g, 14.9 mmol), 2,3-butanedione (1.3 ml, 15 mmol), n-butylamine (1.5 ml, 15 mmol) and ammonium acetate (1.15 g, 14.9 mmol) were mixed with L-proline (0.251 g, 2.24 mmol) in methanol (60 ml). The crude mixture was first purified by flash column chromatography (5% methanol / dichloromethane to 50% methanol / dichloromethane) to give a brown oil. The residue was further purified by flash column chromatography (5% ethyl acetate / hexane to 100% ethyl acetate) to give IM-7a (0.554 g, 15%) as a light brown oil. 1 H NMR (600 MHz, CD3OD): δ 7.27 (t, J= 7. 6 Hz, 1H), 7.14 (d, J= 7.6 Hz, 2H), 3.63 - 3. 48 (m, 2H), 2.23 (s, 3H), 2.17 (s, 3H), 2.04 (s, 6H), 1.49 - 1.40 (p, J= 7.4 Hz, 2H), 1.19 (sext, J= 7.4 Hz, 2H), 0.78 (t, J= 7.4 Hz, 3 H). 13 C NMR (126 MHz, CD3OD): δ 145.11, 139. 87, 132.93, 131.97, 130.51, 128.50, 123.49 , 44.78, 33.50, 20.78, 20.05, 13.79, 12.29, 8.95. C 17 H 25 N2 + (M + H+ ) HRMS (DART) calculated m / z 257.201.23, observed 257.20141.

[0153] 1-n-Butyl-4,5-dimethyl-2-phenyl-1H-imidazole (IM-7b) [ka] According to general procedure A, benzaldehyde (2.0 ml, 20 mmol), 2,3-butanedione (1.9 ml, 22 mmol), n-butylamine (1.9 ml, 20 mmol) and ammonium acetate (1.51 g, 19.6 mmol) were mixed with L-proline (0.260 g, 2.26 mmol) in methanol (80 ml). The residue was first purified by flash column chromatography (50% ethyl acetate / hexanes) to give IM-7b (3.44 g, 77%) as a dark brown oil. Distillation under vacuum using a Hickman apparatus gave a pale yellow oil. 1 H NMR (600 MHz , CD3OD): δ 7.54 - 7.36 (m, 5H), 3.96 - 3.91 (m, 2H),2.22 (s, 3H), 2.15 (s, 3H), 1.59- 1. 49 (p, J = 7.4 Hz, 2H), 1.18 (sext, J = 7.4 Hz, 2H), 0.80 (t, J = 7.4 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 147.03, 133.39, 132.53, 130.11, 129.88, 129.68, 124.91, 45.07, 33.76, 20.63, 13.78, 12.16, 8.97. C 15 H 21 N2 + (M + H + ) HRMS (DART) m / z calculated for 229.16993, found 229.16942.

[0154] 1-n-Butyl-2-(2,6-dimethylphenyl)-4,5-diphenyl-1H-imidazole (IM-8a) [ka] According to general procedure A, 2,6-dimethylbenzaldehyde (2.00 g, 14.9 mmol), diphenylethanedione (3.13 g, 14.9 mmol), n-butylamine (1.5 ml, 15 mmol) and ammonium acetate (1.15 g, 14.9 mmol) were mixed with L-proline (0.257 g, 2.26 mmol) in methanol (60 ml). The residue was purified by flash column chromatography (10% ethyl acetate / hexane). The product was recrystallized from acetonitrile to give IM-8a (0.975 g, 17%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.55 - 7.46 (m, 3H), 7.44 - 7.41 (dm, J = 7.4 Hz, 2H ), 7.40 - 7.38 (dm, J= 7.9 Hz, 2H), 7.34 (t, J= 7.7 Hz, 1H), 7.22 (d, J= 7.7 Hz, 2H), 7.19-7.15 (tm, J = 7.6 Hz, 2H), 7.15-7.11 (tm, J =7.3 Hz, 1H), 3.63 -3.59 (m, 2H),2.22(s, 6H) ), 1.26 (p, J= 7.4 Hz, 2H), 0.94 (sext, J= 7.4 Hz, 2H), 0.56 (t, J= 7.4 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 147.49, 139.87, 138.34, 1 35.44, 132.30, 132.21, 131.38, 130.90, 130 .26, 130.06, 129.94, 129.10, 128.73, 128.0 8, 127.52, 45.10, 33.14, 20.48, 20.31,13.5 2. C 27 H 29 N2 + (M + H + ) HRMS (DART) m / z calculated for 381.23253, actual value 381.23138.

[0155] Synthesis of cations Non-imidazolium cations (for comparative purposes) and imidazolium cations (both inventive and comparative) were prepared as follows.

[0156] Benzyltrimethylammonium bromide(1) [ka] 30% trimethylamine in ethanol (0.76 ml, 3.1 mmol) was treated with benzyl bromide (0.40 ml, 3.4 mmol) in acetonitrile (5 ml). was purified by dissolving in chloroform and precipitating in ether to give 1 (0.693 g, 90%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.63 - 7.60 (dm, J= 7.7 Hz, 2H), 7.59 - 7.52 (m, 3 H), 4.61 (s, 2H), 3.15 (s, 9H). 13 C NMR (126 MHz, CD3OD): δ 134.10, 131.87, 130.26, 129.19, 70.15, 53.19, 53.16, 53.13. C 10 H 16 N + (M + ) calculated HRMS (DART) m / z 150.12773, observed 150.12750.

[0157] 1-Benzyl-3-methylimidazolium bromide (2a) [ka] 1-Methylimidazole (1.0 ml, 13 mmol) was treated with benzyl bromide (1.5 ml, 12 mmol) in acetonitrile (10 ml) according to general procedure B. The residue was purified by dissolving in chloroform and precipitating into ether to give 2a (3.03 g, 98%) as a brown oil. 1 H NMR (600 MHz, CD3OD): δ 9.06 (s, 1H), 7.64 - 7.62 (m, 1H), 7.61 - 7.58 ( m, 1H), 7.47 - 7.40 (m, 4H), 5.44 (s, 2H), 3.94 (s, 3H). 13 C NMR (151 MHz, CD3OD): δ 137.97, 135.25, 130.39, 130.33, 129.71, 125.26, 123.66, 54.11, 36.69. C 11 H 13 N2 + (M + ) calculated HRMS (DART) m / z 173.10732, observed 173.10709.

[0158] 1-Benzyl-2,3-dimethylimidazolium bromide (2b) [ka] Following general procedure B, 1,2-dimethylimidazole (2.00 g, 20.8 mmol) was treated with benzyl bromide (3.0 ml, 25 mmol) in acetonitrile (100 ml). The product was recrystallized from chloroform to give 2b (3.05 g, 55%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.53 (m, 2H), 7.45 - 7.41 (m, 2H), 7.41 - 7.37 (m, J= 7. 3 Hz, 1H), 7.36 - 7.33 (d, J= 7.6 Hz, 2H), 5. 42 (s, 2H), 3.85 (s, 3H), 2.65 (s, 3H). 13 CN MR (126 MHz, CD3OD): δ 146.06, 135.18, 130. 25, 129.84, 129.11, 123.77, 122.43,52.66,35.96, 10.58. C 12 H 15 N2 + (M + ) HRMS (DART) calculated m / z 187.12298, observed 187.12293.

[0159] 1-Ethyl-2,3-dimethylimidazolium iodide (2c) [ka] Following general procedure B, 1,2-dimethylimidazole (2.00 g, 20.8 mmol) was prepared. ) was treated with ethyl iodide (2.0 ml, 25 mmol) in acetonitrile (100 ml). The product was dissolved in chloroform and purified by precipitation into tetrahydrofuran to give 2c (5.01 g, 96%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.57 (d, J= 2.1 Hz, 1H), 7.51 (d, J= 2.1 Hz, 1H), 4.23 (q, J= 7.3 Hz, 2H), 3.85 ( s, 3H), 2.68 (s, 3H), 1.48 (t, J= 7.3 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 145.46, 123.53 , 121.45, 44.73, 36.23, 15.61, 10.89. C7H 13 N2 + (M + ) HRMS (DART) m / z 125.10732 calculated for Actual value: 125.10757.

[0160] 1-Isopropyl-2,3-dimethylimidazolium iodide (2d) [ka] Following general procedure B, 1,2-dimethylimidazole (2.00 g, 20.8 mmol) was treated with 2-iodopropane (2.3 ml, 23 mmol) in acetonitrile (20 ml). The product was dissolved in chloroform and purified by precipitation into ethyl acetate to give 2d (2.36 g, 50%) as a pale beige powder. 1 H NMR (600 M Hz, CD3OD): δ 7.68 (d, J= 2.2 Hz, 1H), 7.54 ( d, J= 2.2 Hz, 1H), 4.75 (hept, J= 6.8 Hz, 1H), 3.87 (s, 3H), 2.72 (s, 3H), 1.54 (d, J= 6.8 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 144.98, 124.02, 118.46, 52.08, 35.91, 22.74, 10.67. C8H 15 N2 + (M + ) calculated HRMS (DART) m / z 139. 12298, actual value 139.12305.

[0161] 1-Butyl-2,3-dimethylimidazolium iodide (2e) [ka] Following general procedure B, 1,2-dimethylimidazole (2.00 g, 20.8 mmol) was treated with n-butyl iodide (2.6 ml, 23 mmol) in acetonitrile (20 ml). The product was dissolved in chloroform and purified by precipitation into ethyl acetate to give 2e (4.57 g, 78%) as a white powder. 1H NMR (600 MHz, CD3OD): δ 7.54 (d, J= 2.1 Hz, 1H), 7.49 (d, J= 2.1 Hz, 1H), 4.17 (m, 2H), 3.84 (s, 3H), 2.66 (s , 3H), 1.82 (p, J= 7.4 Hz, 2H), 1.41 (sext, J= 7.4 Hz, 2H), 1.00 (t, J= 7.4 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 145.65, 123.50, 122.1 2, 49.35, 36.15, 32.74, 20.48, 13.95, 10.77. C9H 17 N2 + (M + ) calculated HRMS (DART) m / z 153. 13863, actual value 153.13876.

[0162] 1-Benzyl-2-(2,6-dimethylphenyl)-3,4,5-trimethylimidazolium iodide (3a) [ka] Following general procedure B, IM-3a (0.400 g, 1.38 mmol) was treated with methyl iodide (0.90 ml, 1.5 mmol) in acetonitrile (1.5 ml). The product was dissolved in chloroform and purified by precipitation into ethyl acetate to give 3a (0.382 g, 72%) as an off-white powder. 1 H NMR (600 MHz, CD3OD): δ 7.52 (t, J= 7.7 Hz, 1H), 7.34 - 7.21 (m, 5H), 6.93 (d, J = 7.4 Hz, 2H), 5.12 (s, 2H), 3 .51 (s, 3H), 2.47-2.44 (m, 6H), 1.88 (s, 6H). 13 C NMR (126 MHz, CD3OD): δ 144.55, 140.88 , 134.83, 133.96, 130.09, 129.70 * , 129.50, 128.50, 128.45,122.52, 50.54, 32.93, 19.69, 9.56, 9.14. C 21 H 25 N2 + (M + ) calculated HRMS (DART) m / z 305.20123, observed 305.20134.

[0163] 1-Benzyl-3,4,5-trimethyl-2-phenylimidazolium iodide (3b) [ka] Following general procedure B, IM-3b (2.54 g, 9.68 mmol) was treated with methyl iodide (0.70 ml, 12 mmol) in acetonitrile (7 ml). The product was dissolved in chloroform and purified by precipitation into ether to give 3b (1.74 g, 50%) as an off-white powder. 1 H NMR (600 MHz, CD3OD): δ 7.74 - 7.69 (t, J= 7.6 Hz, 1H), 7.63 (t, J= 7. 6 Hz, 2H), 7.61 - 7.57 (d, J= 7.6 Hz, 2H), 7. 37 - 7.28 (m, 3H), 7.07 - 7.02 (d, J= 7.6 Hz, 2H), 5.25 (s, 2H), 3.64 (s, 3H), 2.41 (s, 3H) ), 2.24 (s, 3H). 13 C NMR (126 MHz, CD3OD): δ 145.24, 135.44, 133.65, 131.76, 130.78, 13 0.21, 129.33, 129.30, 127.95, 127.33, 123. 41, 50.35, 34.00, 9.14,9.08. C 19 H 21 N2+ (M + ) HRMS (DART) m / z calculated for 277.16993, observed 277.17009.

[0164] 1-Benzyl-2-isopropyl-3,4,5-trimethylimidazolium iodide (3c) [ka] IM-3c (1.07 g, 4.69 mmol) was treated with methyl iodide (0.32 ml, 5.2 mmol) in acetonitrile (5 ml) according to general procedure B. The product was dissolved in chloroform and purified by precipitation into ether to give 3c (1.58 g, 91%) as an orange solid. 1 H NMR (600 MHz, CD3OD): δ 7.41 (t, J= 7.6 Hz, 2H), 7.37 - 7.32 (t, J= 7.6 Hz , 1H), 7.13 - 7.08 (d, J= 7.6 Hz, 2H), 5.49 ( s, 2H), 3.83 (s, 3H), 3.65 (hept, J= 7.3 Hz, 1H), 2.32 (s, 3H), 2.19 (s, 3H), 1.36 (d, J= 7.3 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 149.98, 135.89, 130.33, 129.35, 128.79, 127.23 , 126.97, 49.49, 33.60, 26.62, 19.13, 8.91, 8.90. C 16 H 23 N2 + (M + ) calculated for HRMS(DART)m / z 243.18558, actual value 243.18580.

[0165] 1-Benzyl-2,3,4,5-tetramethylimidazolium bromide (3d) [ka] Following general procedure B, 1,2,4,5-tetramethylimidazole (2.00 g, 16.1 mmol) was treated with benzyl bromide (1.9 ml, 16 mmol) in acetonitrile (10 ml). The product was dissolved in chloroform and purified by precipitation into ether to give 3d (3.60 g, 76%) as an off-white powder. 1 H NMR (600 MHz, CD3OD): δ 7.40 (t, J= 7.7 Hz, 2H), 7.37 - 7.33 (t, J= 7.6 Hz, 1H), 7.19 - 7.14 (d, J= 7.6 Hz, 2H), 5.42 (s, 2H), 3.74 (s, 3H), 2.64 (s, 3H), 2.31 (s, 3H),2.19(s, 3H). 13 C NMR (126 MHz, CD3OD): δ 144.40, 135.40, 130.23, 129.27, 127.79, 127.49, 126.60, 49.42, 33.02, 10.98, 8.97, 8.91. C 14 H 19 N2 + (M + ) is calculated Calculated HRMS (DART) m / z 215.15428, observed 215.1548.

[0166] 1-Benzyl-2-(2,6-dimethylphenyl)-3-methyl-4,5-diphenylimidazolium bromide (4a) [ka] IM-4a (0.350 g, 0.844 mmol) was treated with methyl iodide (0.06 ml, 0.9 mmol) in acetonitrile (1.2 ml) according to general procedure B. The product was purified by dissolving in chloroform and precipitating into ether to give 4a (0.096 g, 22%) as a white powder.1 H NMR (500 MHz, CD3OD): δ 7.64 - 7.44 (m, 11H), 7.35 (d, J= 7.7 Hz, 2H), 7.24 (t, J= 7.6 Hz, 1H), 7.15 (t, J= 7.6 Hz, 2H), 6.66 (d, J= 7.7 Hz, 2H), 5.18 (s, 2H), 3.54 (s, 3H), 2.06 (s, 6H). 13 C NMR (126 MHz, CD3OD): δ 146.19, 140.90, 134.58, 134.37, 134.35, 133.87, 132.68, 132.15, 131.76, 131 .57, 130.47, 130.19, 129.94 * , 129.89, 129. 23, 126.75, 126.43, 122.38, 51.29, 34.14, 19.66. C 23 H 21 N2 + (M + ) HRMS (DART) m / z calculated for 325.16993, actual value 325.16996.

[0167] 1-Benzyl-3-methyl-2,4,5-triphenylimidazolium bromide (4b) [ka] IM-4b (0.880 g, 2.84 mmol) was treated with benzyl bromide (0.40 ml, 3.1 mmol) in acetonitrile (10 ml) according to general procedure B. The product was dissolved in chloroform and purified by precipitation into ether to give 4b (0.567 g, 41%) as an off-white powder. 1 H NMR (600 MHz, CD3OD): δ 7.83 (d, J= 7.6 Hz, 2H), 7.78 - 7.74 (t, J= 7.6 Hz, 1H), 7.70 (t, J= 7.6 Hz, 2H), 7.53 (dm, J= 7.6 Hz, 2H), 7.50 - 7.40 (m, 4H), 7.37 (m, 4H), 7.23 - 7.12 (m, 3H), 6.81 - 6.75 ( m, 2H), 5.29 (s, 2H), 3.63 (s, 3H). 13 C NMR ( 126 MHz, CD3OD): δ 146.40, 135.36, 134.32, 133.88, 133.33, 132.31, 132.18, 131.92, 13 1.32 * , 130.87, 130.02, 129.98, 129.79, 129 .25, 127.95, 127.00, 126.84, 123.49, 51.25 , 35.24. C 29 H 25 N2 + (M + ) HRMS (DART) calculated for m / z 401.20123, measured value 401.20079.

[0168] 1-Benzyl-2-isopropyl-3-methyl-4,5-diphenylimidazolium iodide (4c) [ka] Following general procedure B, IM-4c (1.00 g, 2.89 mmol) was dissolved in acetonitrile. The product was dissolved in chloroform and purified by precipitation into ether to give 4c (1.06 g, 84%) as a pale yellow powder. 1 H NMR (600 MHz, CD3OD): δ δ 7. 54 - 7.49 (d, J= 7.4 Hz, 2H), 7.44 (m, 3H), 7 .37 (m, 5H), 7.33 - 7.28 (m, 3H), 7.12 (d, J= 7.4 Hz, 2H), 5.44 (s, 2H), 3.83 (s, 3H), 3.74 (hept, J= 7.3 Hz, 1H), 1.47 (d, J= 7.3 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 150.82, 135 .93, 134.29, 133.00, 132.60, 132.44, 131.2 7, 131.22, 130.17, 129.88, 129.84, 129.30, 127.41, 127.02, 126.83, 50.43, 35.05, 27.3 4, 19.18. C 26 H 27 N2 + (M + ) HRMS calculated for (DART ) m / z 367.21688, measured value 367.21702.

[0169] 1-Benzyl-2,3-methyl-4,5-diphenylimidazolium iodide (4d) [ka] IM-4d (0.405 g, 1.25 mmol) was treated with methyl iodide (0.09 ml, 1 mmol) in acetonitrile (1.5 ml) according to general procedure B. The product was purified by dissolving in chloroform and precipitating in ether to give 4d (0.190 g, 36%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ δ 7. 50 - 7.39 (m, 6H), 7.37 - 7.29 (m, 5H), 7.29 - 7.25 (dm, J= 7.8 Hz, 2H), 7.08 (dm, J= 7.5 Hz, 2H), 5.38 (s, 2H), 3.74 (s, 3H), 2.78 (s, 3H). 13C NMR (126 MHz, CD3OD): δ 146.00, 135 .36, 133.48, 132.71, 132.31, 132.22, 131.3 4, 131.26, 130.22, 130.02, 129.98, 129.43, 127.65, 126.96, 126.95, 50.28, 34.06, 11.5 4. C 24 H 23 N2 + (M + ) HRMS (DART) m / z calculated for 33 9.18558, actual value 339.18559.

[0170] 1-Benzyl-2-(2,6-dimethylphenyl)-3-ethyl-4,5-diphenylimidazolium bromide (5a) [ka] IM-5a (0.110 g, 0.312 mmol) was treated with benzyl bromide (0.05 ml, 0.4 mmol) in acetonitrile (1 ml) according to general procedure B. The product was purified by dissolving in chloroform and precipitating in ether to give 5a (0.080 g, 49%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.6 5 - 7.45 (m, 11H), 7.36 (d, J= 7.7 Hz, 2H), 7 .24 (t, J= 7.5 Hz, 1H), 7.15 (tmJ= 7.7 Hz, 2H), 6.64 (d, J= 7.7 Hz, 2H), 5.17 (s, 2H), 4.00 (q, J= 7.3 Hz, 2H), 2.06 (s, 6H), 1.01 (t, J = 7.3 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 1 45.59, 140.73, 134.58, 134.37, 134.31, 133 .87, 132.65, 132.16, 131.74, 131.70, 130.4 3, 130.37, 130.12,129.96,129.89, 129.26, 1 26.63, 126.61, 122.40, 51.22, 43.49, 19.92 , 14.96. C 32 H 31 N2 + (M + ) HRMS (DART) calculated for m / z 443.24818, measured value 443.24856.

[0171] 1-Benzyl-3-ethyl-2,4,5-triphenylimidazolium iodide (5b) [ka] IM2-4b (0.825 g, 2.14 mmol) was treated with ethyl iodide (0.19 ml, 2.4 mmol) in acetonitrile (3 ml) according to general procedure B. The product was purified by dissolving in chloroform and precipitating into ether to give 5b (0.805 g, 76%) as an off-white powder. 1 H NMR (600 MHz, CD3OD): δ 7.82 - 7.74 (m, 3H), 7.70 (m, 2H), 7.58 - 7.45 (m, 5H), 7.43 (m, 1H), 7.36 (m, 4H), 7.1 8 (m, 3H), 6.75 (d, J= 7.6 Hz, 2H), 5.25 (s, 2H), 4.11 (q, J= 7.3 Hz, 2H), 1.07 (t, J= 7.3 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 145.84, 135.25, 133.95 *, 133.49, 132.41, 132.34, 132.00, 131.51, 131.36, 130.93, 130.14, 129 .92, 129.84, 129.30,128.08,126.96, 126.87 , 123.51, 51.23, 43.73, 15.46. C 30 H 27 N2 + (M + ) calculated HRMS (DART) m / z 415.21688, observed 415.21657.

[0172] 1-Benzyl-3-n-butyl-2-(2,6-dimethylphenyl)-4,5-diphenylimidazolium iodide (6a) [ka] Following general procedure B, IM-4a (0.500 g, 1.21 mmol) was treated with n-butyl iodide (0.15 ml, 1.3 mmol) in acetonitrile (1 ml). The material was dissolved in chloroform and purified by precipitation into ether to give 6a (0.397 g, 60%) as a pale yellow powder. 1 H NMR (600 MHz, CD3OD): δ 7.63 - 7.54 (m, 5H), 7.50 (m, 6H), 7.36 (dm, J= 7.5 Hz, 2H),7.23 (tm, J= 7.5 Hz, 1H), 7.1 4 (tm, J= 7.6 Hz, 2H), 6.63 (dm, J= 7.6 Hz, 2 H), 5.19 (s, 2H), 3.97 - 3.92 (m, 2H), 2.08 (s, 6H), 1.35 (p, J= 7.4 Hz, 2H), 1.00 (sext, J= 7.4 Hz, 2H), 0.56 (t, J= 7.4 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 145.70, 140.72, 134. 42, 134.35, 134.28, 134.06, 132.69, 132.27 , 131.69, 131.66, 130.41, 130.33, 130.13, 129.92, 129.88, 129.25, 126.70, 126.60, 122.40, 51.32, 47.70, 32.17, 20.30, 20.12, 13.22. C 34 H 35 N2 + (M + ) HRMS (DART) m / z calculated for 47 1.27948, actual value 471.27828.

[0173] 1-Benzyl-3-n-butyl-2,4,5-triphenylimidazolium bromide (6b) [ka]

[0174] IM-6b (1.10 g, 3.12 mmol) was treated with benzyl bromide (0.40 ml, 3.4 mmol) in acetonitrile (3 ml) according to general procedure B. The product was purified by dissolving in chloroform and precipitating in ether to give 6b (0.527 g, 32%) as a white powder. 1 H NMR (600 MHz, CD3OD): δ 7.84 - 7.74 (m, 3H), 7.71 (d, J= 6.8 Hz, 2H), 7.55 (dm, J= 7.6 Hz, 2H), 7.53 - 7.46 (m, 3H), 7. 42 (m, 1H), 7.40 - 7.33 (m, 4H), 7.17 (m, 3H), 6.79 - 6.67 (d, J= 7.5 Hz, 2H), 5.27 (s, 2H ), 4.08 (m, 2H), 1.40 (p, J= 7.4 Hz, 2H), 1.01 (sext, J= 7.4 Hz, 2H), 0.58 (t, J= 7.4 Hz, 3H). 13 C NMR (126 MHz, CD3OD): δ 146.14, 135 .26, 134.01,133.96, 132.29, 132.20, 131.90, 131.54, 131.42, 131.03, 130.23, 130.03, 129.85, 129.37, 128.02, 126.98, 126.82, 123 .54, 51.23, 47.90, 32.39, 20.21, 13.29. C 32 H 31 N2 + (M + ) HRMS (DART) calculated m / z 443.24818, observed 443.24683.

[0175] 1,3-Di-n-butyl-2-(2,6-dimethylphenyl)-4,5-dimethylimidazolium iodide (7a) [ka] Following general procedure B, IM-7a (0.240 g, 0.937 mmol) was treated with n-butyl iodide (0.13 ml, 1.1 mmol) in acetonitrile (1.5 ml). The product was purified by dissolving in chloroform and precipitating into ether to give 7a (0.366 g, 89%) as a light beige powder. 1 H NMR (600 MHz, CD3OD): δ 7.57 (t, J= 7.7 Hz, 1H), 7.39 (d, J= 7.7 Hz, 2H), 3.89 - 3.75 (m, 4H), 2.43 (s, 6H), 2.12 (s, 6H), 1.59 - 1.52 (p,J= 7.4 Hz, 4H), 1.26 (sext, J= 7.4 Hz, 4H), 0.82 (t, J= 7.4 Hz, 6H). 13C NMR (126 MHz, CD3OD): δ 143.30, 140.40, 133.97, 130.02, 128.66, 12 2.75, 46.91, 32.43, 20.61, 20.09, 13.57, 9.06. C 21 H 33 N2 + (M + ) HRMS (DART) m / z calculated for 3 13.26383, actual value 313.26388.

[0176] 1,3-Di-n-butyl-4,5-dimethyl-2-phenylimidazolium iodide (7b) [ka] IM-7b (0.262 g, 1.15 mmol) was treated with butyl iodide (0.15 ml, 1.4 mmol) in acetonitrile (1 ml) according to general procedure B. The product was dissolved in chloroform and purified by precipitation into ether to give 7b (0.298 g, 63%) as an orange waxy solid. 1 H NMR (600 MHz, CD3OD): δ 7.80 - 7.75 (t, J= 7.4 Hz 1H), 7.73 (t , J= 7.6 Hz, 2H), 7.68 - 7.65 (d, J= 7.6 Hz, 2H), 3.99 - 3.85 (m, 4H), 2.40 (s, 6H), 1.65 - 1.56 (p, J= 7.4 Hz, 4H),1,20 (sext, J= 7.4 Hz, 4H), 0.78 (t, J= 7.4 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 144.16, 133.61, 131.93, 130.89, 128.00, 123.85, 79.60, 46.95, 32.70, 20.50, 13.59, 9.04. C 19 H 29 N2 + (M +) HR calculated for MS(DART) m / z 285.23253, found 285.23174.

[0177] 1,3-Di-n-butyl-2-(2,6-dimethylphenyl)-4,5-diphenylimidazolium iodide (8a) [ka] Following general procedure B, IM-8a (1.86 g, 4.89 mmol) was treated with n-butyl iodide (0.61 ml, 5.4 mmol) in acetonitrile (5 ml). The product was dissolved in chloroform and purified by precipitation into ether to give 8a (1.27 g, 46%) as a pale beige powder. 1 H NMR (600 MHz, CD3OD): δ 7.63 (t, J= 7.7 Hz, 1H), 7.57 - 7.54 (m, 4H), 7.54 - 7.44 (m, 8H), 3.99 - 3.89 (m, 4H), 2.34 (s, 6H), 1.40 - 1.29 (p, J= 7.4 Hz, 4H) , 1.01 (sext, J= 7.4 Hz,4H), 0.57 (t, J= 7.4 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 144.95, 140.54, 134.31, 134.06, 132.26, 131.61, 13 0.29, 130.23, 126.76, 122.42, 47.65, 32.22 , 20.39, 20.32, 13.24. C 31 H 37 N2 + (M + ) is calculated Calculated HRMS (DART) m / z 437.29513, observed 437.29517.

[0178] 1,3-Di-n-butyl-2,4,5-triphenylimidazolium iodide (8b) [ka] Following general procedure B, IM-6b (3.74 g, 10.6 mmol) was treated with n-butyl iodide (1.8 ml, 16 mmol) in acetonitrile (10 ml). The product was purified by dissolving in chloroform and precipitating into ether to give 8b (3.50 g, 61%) as a white powder. 1 H NMR (500 MHz, CD3OD): δ 8.02 ( d, J= 7.6 Hz, 2H), 7.79 (m, 3H), 7.63 - 7.56 (d, J= 7.3 Hz,4H), 7.50 - 7.40 (m, 6H), 4.02 (m, 4H), 1.39 (p, J= 7.4 Hz, 4H), 0.98 (sext , J= 7.4 Hz, 4H), 0.56 (t, J= 7.4 Hz, 6H). 13 C NMR (126 MHz, CD3OD): δ 145.32, 133.93, 133.36, 132.36, 132.18, 131.39, 131.00, 130.0 8, 127.19, 123.79, 47.73, 32.47, 20.27, 13.30. C 29 H 33 N2 + (M + ) HRMS (DART) m / z 4 calculated for 09.26383, actual value 409.26371.

[0179] General Procedure C: Model Compound Study Procedure Stock solutions of basic methanol were prepared by dissolving KOH (1M, 2M or 5M) and 3-(trimethylsilyl)-1-propanesulfonic acid sodium salt (0.025M) in CDOH. Model compounds (0.05M for 1M KOH, 0.03M for 2M and 5M KOH) were dissolved in methanol solution (0.5mL) and the glass The NMR tube was flame sealed and the initial 1 The tubes were analyzed by H NMR spectroscopy. Integration of selected signals in the model compounds relative to the signal associated with 3-(trimethylsilyl)-1-propanesulfonic acid sodium salt provided the initial amount of the model compound. The tubes were heated in an oil bath at 80° C. At specific time points, every 5 days, the tubes were removed and cooled to room temperature. 1 Analysis by 1 H NMR spectroscopy was performed to determine the amount of model compound remaining.

[0180] result The stability results for the test compounds are summarized in Table I: [Table I] TIFF0007617069000060.tif242170TIFF0007617069000061.tif68170 a Reaction conditions: [ImX]:[KOH] = 1:20, 1:67, 1:167 (1M, 2M and 5M KOH experiments, respectively, and at 80°C). b Relative to the internal standard, 3-(trimethylsilyl)-1-propanesulfonic acid sodium salt. 1 Cation survival measured by 1 H NMR spectroscopy. c The imidazole concentration decreased from 0.05 M to 0.03 M at higher base concentrations due to the reduced solubility of the organic salt. d Not measured. e For samples expected to be less stable, analyses were performed at time intervals of less than 5 days. f Analysis was performed after 17 days.

[0181] Synthesis of imidazolium cation-functionalized monomers Imidazolium-functionalized monomers of formulae (IIA), (IIB) and (IIC) suitable for ROMP were prepared as follows. Exemplary compounds prepared are shown, but one of skill in the art will recognize when the illustrated method and variations thereof are in accordance with formulae (IIA)-(IIC) and when they are not (different R 1 It will be readily understood that the above-mentioned compounds can be used to prepare additional compounds, both bearing substituents and, if ROMP is anticipated, optionally bearing different non-cyclooctene strained rings.

[0182] Monomer synthesis of an exemplary embodiment of formula (IIA): [ka]

[0183] Monomer synthesis of an exemplary embodiment of formula (IIB): [ka]

[0184] Monomer synthesis of an exemplary embodiment of formula (IIC): [ka]

[0185] Polymer synthesis Examples of embodiments of imidazolium-functionalized polymers according to the present invention were prepared as follows:

[0186] Polymer synthesis from monomers of formula (IIC): [ka]

[0187] Generally, polymerization can be carried out by ROMP as described above. The imidazolium monomers can be polymerized as homopolymers or copolymerized with monomer precursors for HRUs. Monomer precursors of HRUs in ROMP are well known in the art. In certain embodiments of the invention, the monomers are aliphatic (C1-C 20 ) hydrocarbons. Polymers can be made in which all repeat units are IRUs; polymers can be made in which IRUs and HRUs are present. and one can make polymers in which some of the HRUs are crosslinked HRUs. To make crosslinked polymer species in which the crosslinks are in the HRUs, the aliphatic hydrocarbon is linked to two carbon rings: [ka] (Z 3 (C1~C 20 ) is a hydrocarbon. A monomer containing a double bond may be added to each of ).

[0188] Other polymerization methods can also be used to prepare the polymers of the invention with imidazolium cations appended to the polymer backbone. In addition to ring-opening metathesis polymerization (ROMP) of strained cyclic olefins, polycations are made from pre-functionalized cationic monomers by controlled radical polymerization such as atom transfer radical polymerization (ATRP) or reversible addition fragmentation polymerization (RAFT). Polymerization of α-olefins with transition metal coordination complexes is another possibility for monomers based on imidazolium cations, since the bulky substituents on the heteroatom ring can prevent deleterious side reactions between the catalyst and the monomer. Alternatively, imidazolium cations can be easily attached to polymer backbones containing electrophiles via post-polymerization modification approaches. For example, imidazole reacts with benzyl or alkyl halides present in existing polymers, resulting in direct attachment of the imidazolium to the polymer. Polymers with reactive electrophilic sites can be synthesized by step-growth polymerization, radical polymerization or transition metal catalyzed coordination insertion polymerization routes.

[0189] The following is an example of an embodiment in which the polymerization was carried out by polyolefin metathesis: [ka]

[0190] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. Additionally, the terms "comprise" (including any form of comprise, such as "comprises" and "comprising"), "have" (including any form of have, such as "has" and "having"), "include" (including any form of include, such as "includes" and "including"), "contain" (including any form of contain, such as "contains" and "containing"), and other grammatical variations will be understood to be open-ended linking verbs. As a result, a method or composition of matter / article that "comprises," "has," "includes," or "contains" one or more steps or elements possesses those one or more steps or elements, but is not limited to having only those one or more steps or elements. Similarly, a method step or article element that "comprises," "has," "includes," or "contains" one or more features possesses one or more features, but is not limited to having only those one or more features.

[0191] As used herein, the terms "comprising," "has," "including," or "containing," as well as other grammatical variations, encompass the terms "consisting of" and "consisting essentially of."

[0192] As used herein, "consisting essentially of" or grammatical variations thereof shall be deemed to specify the recited features, integers, steps or ingredients, but shall not preclude the addition of one or more additional features, integers, steps, ingredients, but only if such additional features, integers, steps, ingredients, or groups thereof do not materially alter the basic and novel characteristics of the claimed composition or method.

[0193] Publications cited in this specification are herein incorporated by reference as if each individual publication was specifically and individually indicated to be incorporated by reference in this specification as if fully set forth.

[0194] Subject matter incorporated by reference is not to be considered an alternative to the claims unless expressly stated.

[0195] Where one or more ranges are referenced throughout this specification, each range is intended to be a shorthand form of presenting information, and the range will be understood to include each discrete point within the range as if each point within the range were fully set forth herein.

[0196] While several aspects and embodiments of the present invention have been described and illustrated herein, alternative aspects and embodiments may be devised by those skilled in the art to accomplish the same purposes, and it is therefore intended that this disclosure and the appended claims cover all such further and alternative aspects and embodiments that fall within the true spirit and scope of the present invention.

Claims

1. Formula (III'): 【Chemistry 1】 [however, R ２’ is C １ ~C ６ is alkyl; R ３’ is methyl or R ３ and R ３ is C ２ ~C １６ is hydrocarbyl; R ４ and R ５ are each independently １ ~C １６ hydrocarbyl or R ４ and R ５ together with the carbon atoms to which they are attached form a ring selected from benzene, cyclooctene, or norbornene; X － is the counterion, The wavy lines indicate points of attachment to adjacent polymer repeat units; W is C ３ is hydrocarbyl; Y is C ４ is hydrocarbyl; and Z is C １ ~C １３ is a hydrocarbyl, １ ~C １３ One carbon atom of the hydrocarbyl is O-substituted. A polymer comprising an imidazolium-containing repeat unit represented by the formula:

2. R ３’ The polymer of claim 1 , wherein is methyl.

3. R ３’ C ２ ~C ７ The polymer of claim 1 which is hydrocarbyl.

4. R ３’ C ２ ~C ４ 2. The polymer of claim 1 which is alkyl or benzyl.

5. R ３’ The polymer of claim 1 , wherein is benzyl.

6. R ４ and R ５ are each independently phenyl or C １ ~C ３ The polymer of any one of claims 1 to 5, which is alkyl.

7. R ４ and R ５ The polymer of claim 6, wherein each is phenyl.

8. R ３’ is n-butyl; and R ４ and R ５ The polymer of claim 1 , wherein each is independently phenyl or methyl.

9. X － A polymer according to any one of claims 1 to 8, wherein is selected from hydroxides, halides, bicarbonates, carbonates, nitrates, cyanides, carboxylates and alkoxides.

10. Formula (IIIA'): 【Chemistry 2】 [however, R ２’ is C １ ~C ６ is alkyl; R ３’ is methyl or R ３ and R ３ is C ２ ~C １６ is hydrocarbyl; R ４ and R ５ are each independently １ ~C １６ hydrocarbyl or R ４ and R ５ together with the carbon atoms to which they are attached form a ring selected from benzene, cyclooctene, or norbornene; X － is the counterion, The wavy lines indicate points of attachment to adjacent polymer repeat units; W is C ３ is hydrocarbyl; Y is C ４ is hydrocarbyl; m is 1; and Z １ａ is C １ to C10 hydrocarbyl. The polymer of claim 1 , comprising an imidazolium-containing repeat unit represented by:

11. Z １ａ is C １ ~C ８ The polymer of claim 10 which is hydrocarbyl.

12. Z １ａ - (CH ２ ) ｐ - (Ph) ｑ - (CH ２ ) ｒ -, where p is 1-2, q is 0 or 1; and r is 1-2.

13. Formula (IIIB'): 【Chemistry 3】 [however, R ２’ is C １ ~C ６ is alkyl; R ３’ is methyl or R ３ and R ３ is C ２ ~C １６ is hydrocarbyl; R ４ and R ５ are each independently １ ~C １６ hydrocarbyl or R ４ and R ５ together with the carbon atoms to which they are attached form a ring selected from benzene, cyclooctene, or norbornene; X － is the counterion, The wavy lines indicate points of attachment to adjacent polymer repeat units; W is C ３ is hydrocarbyl; Y is C ４ is hydrocarbyl; m is 1; n is 1 to 8. The polymer of claim 1 , comprising an imidazolium-containing repeat unit represented by:

14. The polymer has the following structure: 【Chemistry 4】 The polymer according to any one of claims 1 to 12, having the formula:

15. The polymer has the following structure: 【Chemistry 5】 The polymer according to any one of claims 1 to 12, having the formula:

16. The polymer according to any one of claims 1 to 15, in the form of a film.

17. A fuel cell comprising a polymer according to any one of claims 1 to 15, an anode, and a cathode.

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