PROCESS OF FORMING A CONJUGATED POLYMER

Abstract

A process of forming a conjugated polymer comprising polymerising a first monomer and a second monomer in the presence of a palladium catalyst and a base, in a solvent system comprising a first solvent, a second solvent and water; wherein: the first and second monomers are is dissolved in the solvent system; and the solvent system is a single phase. The first monomer may be substituted with a polar group, e.g. an ionic group.

Claims

1. A process of forming a conjugated polymer comprising polymerising a first monomer and a second monomer in the presence of a palladium catalyst and a base, in a solvent system comprising a first solvent and a second solvent; wherein: the first and second monomers are dissolved in the solvent system; the solvent system is a single phase; the first monomer is a compound of Formula 1:
X.sup.1-Ar.sup.1-X.sup.1 Formula 1 wherein Ar.sup.1 comprises at least one aromatic or heteroaromatic group and is substituted with at least one ionic substituent comprising an anionic or cationic group and a counterion; the second monomer is a compound of Formula 2:
X.sup.2-Ar.sup.2-X.sup.2 Formula 2: wherein Ar.sup.2 comprises at least one aromatic or heteroaromatic group; and each X.sup.1 and X.sup.2 is individually selected from a halogen, OSO.sub.2R.sup.a, boronic acid, and a boronic ester, wherein R.sup.a is an optionally substituted aryl or alkyl group; and at least one X.sup.1 or X.sup.2 is a halogen or OSO.sub.2R.sup.a, the remaining X.sup.1 and X.sup.2 groups being a boronic acid, or a boronic ester.

2. The process according to claim 1 wherein the solvent system further comprises water.

3. The process according to claim 1, wherein the second solvent is a non-polar solvent.

4. The process according to claim 3, wherein the second solvent is selected from benzene having one or more alkyl substituents or a mixture thereof.

5. The process according to claim 1, wherein the second solvent is immiscible with water.

6. The process according to claim 1, wherein the first solvent is a polar solvent.

7. The process according to claim 5 wherein the first solvent is a protic solvent.

8. The process according to claim 5, wherein the first solvent is selected from C.sub.1-10 alcohols or diols, tetrahydrofuran, acetic acid, acetone, dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile or a mixture thereof.

9. The process according to claim 8 wherein the first solvent is selected from methanol, ethanol, propanol and butanol.

10. The process according to claim 1, wherein the first solvent is miscible with water.

11. The process according to claim 1 wherein the first solvent is miscible with the second solvent.

12. The process according to claim 1 wherein at least one of Ar.sup.1 and Ar.sup.2 is an arylene group.

13. The process according to claim 12 wherein the arylene group is selected from: ##STR00014## wherein each R.sup.13 is independently a substituent; c is 0, 1, 2, 3 or 4, each d is independently 0, 1, 2 or 3; and e is 0, 1 or 2; provided that at least one R.sup.13 is an ionic substituent.

14. The process according to claim 1 wherein Ar.sup.1 is an arylene group according to claim 13.

15. The process according to claim 1 wherein Ar.sup.2 is an arylene group according to claim 13.

16. The process according to claim 1 wherein Ar.sup.2 comprises a heteroarylene or a (hetero)arylamine group.

17. The process according to claim 1 wherein each Ar.sup.2 is unsubstituted or substituted only with one or more non-ionic substituent.

18. The process according to claim 1, wherein Ar.sup.1 is substituted with one or more ionic substituents of formula -(Sp)m-(R.sup.x)n wherein Sp is a spacer group; m is 0 or 1; R.sup.x in each occurrence is an ionic group; n is 1 if m is 0; and n is at least 1, optionally 1, 2, 3 or 4, if m is 1.

19. The process according to claim 1, wherein each ionic group is individually selected from: ##STR00015## wherein each Y is individually selected from H, C.sub.1-C.sub.20 hydrocarbyl groups and C.sub.1-30 alkyl in which one or more non-adjacent C atoms other than C atoms at the ends of the alkyl chain are replaced with O.

20. A process of forming a conjugated polymer comprising polymerising a first monomer and a second monomer in the presence of a palladium catalyst and a base, in a solvent system comprising a first solvent and a second solvent; wherein: the first and second monomers are dissolved in the solvent system; the solvent system is a single phase; the first solvent is selected from C.sub.1-10 alcohols or diols, tetrahydrofuran, acetic acid, acetone, dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile or a mixture thereof; the first monomer is a compound of Formula 1:
X.sup.1-Ar.sup.1-X.sup.1 Formula 1 wherein Ar.sup.1 comprises at least one aromatic or heteroaromatic group; the second monomer is a compound of Formula 2:
X.sup.2-Ar.sup.2-X.sup.2 Formula 2: wherein Ar.sup.2 comprises at least one aromatic or heteroaromatic group; and each X.sup.1 and X.sup.2 is individually selected from a halogen, OSO.sub.2R.sup.a, boronic acid, and a boronic ester, wherein R.sup.a is an optionally substituted aryl or alkyl group; and at least one X.sup.1 or X.sup.2 is a halogen or OSO.sub.2R.sup.a, the remaining X.sup.1 and X.sup.2 groups being a boronic acid, or a boronic ester; the first monomer has a greater solubility in water at 25 C. than the second monomer; and the second monomer has a greater solubility in toluene at 25 C. than the first monomer.

Description

DESCRIPTION OF DRAWINGS

[0038] FIG. 1 shows the FT-IR spectra for a first polymer according to some embodiments of the present disclosure and the monomers used to form that polymer;

[0039] FIG. 2 shows the FT-IR spectra for a second polymer according to some embodiments of the present disclosure and the monomers used to form that polymer; and

[0040] FIG. 3 shows the absorption spectra for the second polymer and a monomer used to form that polymer.

DETAILED DESCRIPTION

[0041] Unless the context clearly requires otherwise, throughout the description and the claims, the words comprise, comprising, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to. Additionally, the words herein, above, below, and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word or, in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

[0042] The teachings of the technology provided herein can be applied to other systems, not necessarily the system described below. The elements and acts of the various examples described below can be combined to provide further implementations of the technology. Some alternative implementations of the technology may include not only additional elements to those implementations noted below, but also may include fewer elements.

[0043] These and other changes can be made to the technology in light of the following detailed description. While the description describes certain examples of the technology, and describes the best mode contemplated, no matter how detailed the description appears, the technology can be practiced in many ways. As noted above, particular terminology used when describing certain features or aspects of the technology should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the technology with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the technology to the specific examples disclosed in the specification, unless the Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the technology encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the technology under the claims.

[0044] To reduce the number of claims, certain aspects of the technology are presented below in certain claim forms, but the applicant contemplates the various aspects of the technology in any number of claim forms.

[0045] In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of implementations of the disclosed technology. It will be apparent, however, to one skilled in the art that embodiments of the disclosed technology may be practiced without some of these specific details.

[0046] The present inventors have found that a conjugated polymer having repeat units with polar, e.g. ionic, substituents may be formed by polymerisation of monomers in which at least one monomer is substituted with at least one polar substituent by use of a single phase solvent system containing a first solvent, a second solvent and, optionally, water and in which the first and second monomers dissolve. Consequently, an additional post-polymerisation functionalisation step of a polymer to convert a non-ionic substituent to an ionic substituent may be avoided, and impurities arising from unconverted polymer in any post-polymerisation functionalisation step may be avoided. The present inventors also have found that the present polymerisation allows for the formation of polymers with ionic groups that cannot be readily formed using post-polymerisation functionalisation.

[0047] As illustrated in Scheme 1, a monomer for forming repeat units Ar.sup.1 having leaving groups X.sup.1 undergoes polymerisation with a monomer for forming repeat units Ar.sup.2 (which may be the same as or different from Ar.sup.1) having leaving groups X.sup.2 to form a carbon-carbon bond between sp2 hybridised carbon atoms of Ar.sup.1 and Ar.sup.2:

##STR00003##

[0048] It will be understood by the skilled person that when both X.sup.1s are the same, a monomer X.sup.1-Ar.sup.1-X.sup.1 will not polymerise to form a direct carbon-carbon bond with another monomer X.sup.1-Ar.sup.1-X.sup.1. When both X.sup.2s are the same, a monomer X.sup.2-Ar.sup.2-X.sup.2 will not polymerise to form a direct carbon-carbon bond with another monomer X.sup.2-Ar.sup.2-X.sup.2.

[0049] This selectivity means that the ordering of repeat units in the polymer backbone can be controlled such that all or substantially all Ar.sup.1 repeat units formed by polymerisation of X.sup.1-Ar.sup.1-X.sup.1 are adjacent, on both sides, to Ar.sup.2 repeat units.

[0050] In the example of Scheme 1 above, an AB copolymer is formed by copolymerisation of two monomers in a 1:1 ratio, however, it will be appreciated that more than two different monomers may be used in the polymerisation, and any ratio of monomers may be used.

[0051] According to some embodiments of the present disclosure there is provided a process of forming a conjugated polymer comprising polymerising at least one first monomer and at least one second monomer in the presence of a palladium catalyst and a base, in a solvent system comprising a first solvent, a second solvent and, optionally, water, wherein the first solvent dissolves the first monomer and the second solvent dissolves the second monomer.

[0052] The first monomer is a compound of Formula 1:

X.sup.1-Ar.sup.1-X.sup.1 Formula 1

wherein Ar.sup.1 comprises at least one aromatic or heteroaromatic group and is substituted with at least one polar substituent, e.g. at least one ionic substituent; each X.sup.1 is bound directly to an sp.sup.2 hybridised carbon atom of Ar.sup.1 and is individually selected from the group consisting of a halogen, OSO.sub.2R.sup.a, boronic acid, and a boronic ester, wherein R.sup.a is an optionally substituted aryl or alkyl group.

[0053] The second monomer is a compound of Formula 2:

X.sup.2-Ar.sup.2-X.sup.2 Formula 2:

wherein Ar.sup.2 comprises at least one aromatic or heteroaromatic group; each X.sup.2 is bound directly to an sp.sup.2 hybridised carbon atom of Ar.sup.2 and is individually selected from a halogen, OSO.sub.2R.sup.a, boronic acid, and a boronic ester, wherein R.sup.a is an optionally substituted aryl or alkyl group.

[0054] Preferably, each X.sup.1 is bound directly to a carbon atom of an aromatic or heteroaromatic ring.

[0055] Preferably, each X.sup.2 is bound directly to a carbon atom of an aromatic or heteroaromatic ring.

[0056] Any two of the X.sup.1 and X.sup.2 groups of Monomers 1 and 2 are selected from a halogen or OSO.sub.2R.sup.a; and the other two of the X.sup.1 and X.sup.2 groups are selected from boronic acid, or a boronic ester.

[0057] The first and second monomers include monomers in which at least one X.sup.1 or X.sup.2 is a halogen or OSO.sub.2R.sup.a, the remaining X.sup.1 and X.sup.2 groups being a boronic acid, or a boronic ester.

[0058] In some embodiments, each X.sup.1 is boronic acid, or a boronic ester and each X.sup.2 is a halogen or OSO.sub.2R.sup.a.

[0059] In some embodiments, each X.sup.1 is a halogen or OSO.sub.2R.sup.a and each X.sup.2 is a boronic acid, or a boronic ester.

[0060] In some embodiments, one X.sup.1 is a boronic acid or a boronic ester and the other X.sup.1 is a halogen or OSO.sub.2R.sup.a and/or one X.sup.2 is a boronic acid or a boronic ester and the other X.sup.2 is a halogen or OSO.sub.2R.sup.a.

[0061] Optionally, at least 40 mol %, optionally at least 45 mol %, preferably 50 mol %, of the X.sup.1 and X.sup.2 groups are a boronic acid or a boronic ester and at least 40 mol %, optionally at least 45 mol %, preferably 50 mol %, of the X.sup.1 and X.sup.2 groups are a halogen or OSO.sub.2R.sup.a.

[0062] Conjugated Polymer

[0063] The conjugated polymer may be a homopolymer or may be a copolymer comprising two or more different repeat units.

[0064] By conjugated polymer is meant a polymer comprising repeat units in the polymer backbone that are directly conjugated to adjacent repeat units. The conjugation may extend across the whole of the polymer backbone or partially across the polymer backbone, i.e. each repeat unit may have one or more structural sub-units that are conjugated or that break any conjugation path across the repeat unit.

[0065] Conjugated polymers include, without limitation, polymers comprising one or more of arylene, heteroarylene and vinylene groups conjugated to one another along the polymer backbone.

[0066] The polymer may have a linear, branched or crosslinked backbone.

[0067] The polymer may have a solubility of at least 0.01 mg/ml in an alcoholic solvent, optionally in the range of 0.01-10 mg/ml. Optionally, solubility is at least 0.1 or 1 mg/ml. The solubility is measured at 25 C. Preferably, the alcoholic solvent is a C.sub.1-10 alcohol, more preferably methanol. Solubility of the polymer may be adjusted by selection of substituents of the polymer. The polymer may have a solubility of at least 0.01 mg/ml in water at 25 C., optionally a solubility in the range of 0.01-10 mg/ml

[0068] Ionic Substituents

[0069] Ar.sup.1 is substituted with at least one polar substituent, optionally at least one ionic substituent.

[0070] Ar.sup.2 may or may not be substituted with one or more polar, e.g. ionic, substituents.

[0071] Exemplary ionic substituents have formula -(Sp)m-(R.sup.x)n wherein Sp is a spacer group; m is 0 or 1; R.sup.x independently in each occurrence is an ionic group; n is 1 if m is 0; and n is at least 1, optionally 1, 2, 3 or 4, if m is 1.

[0072] Preferably, Sp is selected from: [0073] C.sub.1-20 alkylene or phenylene-C.sub.1-20 alkylene wherein one or more non-adjacent C atoms may be replaced with O; S, N or CO; [0074] a C.sub.6-20 arylene or 5-20 membered heteroarylene, more preferably phenylene, which, in addition to the one or more substituents R.sup.x may be unsubstituted or substituted with one or more substituents, optionally one or more C.sub.1-20 alkyl groups wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, CO, COO, NR.sup.1 or SiR.sup.1.sub.2 wherein R.sup.1 is a C.sub.1-12 hydrocarbyl group.

[0075] R.sup.x may be an anionic or cationic group. Exemplary anionic groups are COO.sup., a sulfonate group; hydroxide; sulfate; phosphate; phosphinate; or phosphonate. An exemplary cationic group is N(R.sup.5).sub.3.sup.+ wherein R.sup.5 in each occurrence is H or C.sub.1-12 hydrocarbyl. Preferably, each R.sup.5 is a C.sub.1-12 hydrocarbyl.

[0076] Exemplary ionic substituents are:

##STR00004##

wherein each Y is individually selected from H, C.sub.1-C.sub.20 hydrocarbyl groups and C.sub.1-30 alkyl in which one or more non-adjacent C atoms other than C atoms at the ends of the alkyl chain are replaced with O. For example, each Y may be selected from C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkenyl, C.sub.6-C.sub.20 aryl group, C.sub.3-C.sub.20 aliphatic cyclic groups and groups of formula (CH.sub.2CH.sub.2O).sub.nAk wherein n is at least 1, optionally 1-10, and Ak is C.sub.1-5 alkyl. For example, each Y may be selected from methyl, ethyl, propyl, butyl, phenyl or tolyl groups.

[0077] Where an ionic substituent is present, the polymer further comprises a charge-balancing counterion to balance the charge of the ionic substituents.

[0078] Cationic counterions are optionally selected from a metal cation, optionally Li.sup.+, Na.sup.+, K.sup.+, Cs.sup.+, preferably Cs.sup.+, or an organic cation, optionally ammonium, such as tetraalkylammonium, ethylmethyl imidazolium or pyridinium.

[0079] Anionic counterions are optionally selected from a halide; a sulfonate group, optionally mesylate or tosylate; hydroxide; carboxylate; sulfate; phosphate; phosphinate; phosphonate; or borate.

[0080] Non-Ionic Substituents

[0081] Ar.sup.2 is preferably substituted with at least one non-ionic substituent. In some embodiments, Ar.sup.2 is unsubstituted or substituted with one or more non-ionic substituents only.

[0082] In some embodiments, Ar.sup.1 is substituted with one or more ionic substituents only. In some embodiments, Ar.sup.1 is substituted with at least one non-ionic substituent.

[0083] Exemplary non-ionic substituents are: [0084] C.sub.1-20 alkyl wherein one or more non-adjacent, non-terminal C atoms may be replaced with O, S, CO, COO, NR.sup.1 or SiR.sup.1.sub.2 wherein R.sup.1 is a C.sub.1-12 hydrocarbyl group; and [0085] C.sub.6-20 aryl, e.g. phenyl, which is unsubstituted or substituted with one or more substituents, optionally one or more substituents selected from F; CN; NO.sub.2; and C.sub.1-12 alkyl wherein or more non-adjacent, non-terminal C atoms may be replaced with O, S, CO, COO, NR.sup.1 or SiR.sup.1.sub.2.

[0086] A non-terminal C atom of an alkyl group as used herein means a C atom other than the C atom of the methyl group at the end of an n-alkyl group or the C atom of the methyl groups at the ends of a branched alkyl chain.

[0087] Preferably, any non-ionic substituents of Ar.sup.2 are non-polar, e.g. C.sub.1-20 hydrocarbyl groups including, without limitation, C.sub.1-20 alkyl, unsubstituted phenyl and phenyl substituted with one or more C.sub.1-6 alkyl groups

[0088] Preferably, any non-ionic substituents of Ar.sup.1 are non-polar. An exemplary non-ionic polar group has formula O(R.sup.14O).sub.qR.sup.15 wherein R.sup.14 in each occurrence is a C.sub.1-10 alkylene group, optionally a C.sub.1-5 alkylene group, preferably C.sub.2H.sub.4, wherein one or more non-adjacent, non-terminal C atoms of the alkylene group may be replaced with O, R.sup.15 is H or C.sub.1-5 alkyl, and q is at least 1, optionally 1-10. Preferably, q is at least 2. More preferably, q is 2 to 5. The value of q may be the same in all the polar groups of formula O(R.sup.14O).sub.qR.sup.15. The value of q may differ between polar groups of the same polymer.

[0089] Repeat Units

[0090] The repeat unit Ar.sup.1 formed by polymerisation of Monomer 1 contains at least one arylene or heteroarylene group and is substituted with at least one polar substituent, e.g. at least one ionic substituent. The one or more substituents of Ar.sup.1 may be ionic only, non-ionic only or a combination thereof.

[0091] The repeat unit Ar.sup.2 formed by polymerisation of Monomer 2 contains at least one arylene or heteroarylene group. Ar.sup.2 may be unsubstituted or substituted with one or more substituents which may independently be ionic or non-ionic.

[0092] Preferably, the or each Monomer 1 has greater solubility than the or each Monomer 2 in water at 25 C.

[0093] Preferably, the or each Monomer 2 has greater solubility than the or each Monomer 1 in toluene in water at 25 C.

[0094] It will be understood that the solubilities of Monomers 1 and 2 may be adjusted by selection of their substituents.

[0095] Exemplary repeat units Ar.sup.1 and Ar.sup.2 include arylene repeat units; heteroarylene repeat units; and (hetero)arylamine repeat units.

[0096] Arylene repeat units may be selected from phenylene, fluorene, benzofluorene, phenanthrene, dihydrophenanthrene, naphthalene and anthracene, more preferably fluorene or phenylene, most preferably fluorene.

[0097] The, or each, arylene repeat unit may be unsubstituted or substituted with one or more substituents selected from ionic and non-ionic substituents. Preferably, at least one arylene repeat unit is substituted with at least one ionic group.

[0098] The repeat units of a light-emitting polymer may consist of one or more arylene repeat units as described herein.

[0099] Arylene repeat units may be selected from repeat units of formulae (I)-(IV):

##STR00005##

wherein each R.sup.13 is a substituent, optionally an ionic or non-ionic substituent as described above; c is 0, 1, 2, 3 or 4, preferably 1 or 2; each d is independently 0, 1, 2 or 3, preferably 0 or 1; and e is 0, 1 or 2, preferably 2.

[0100] In the case where Ar.sup.1 is a repeat unit of formula (I), (II), (III) or (IV), at least one R.sup.13 is a polar substituent, preferably an ionic substituent.

[0101] In the case where Ar.sup.2 is an arylene repeat unit, optionally a repeat unit of formula (I), (II), (III) or (IV), it is optionally unsubstituted or substituted with one or more ionic or non-ionic substituents. In some preferred embodiments, an arylene repeat unit Ar.sup.2 is substituted with non-ionic substituent only, optionally one or more C.sub.1-20 hydrocarbyl groups. Hydrocarbyl groups as described herein include, without limitation, C.sub.1-20 alkyl, unsubstituted phenyl and phenyl substituted with one or more C.sub.1-6 alkyl groups.

[0102] In some embodiments of the present disclosure, the conjugated polymer is a homopolymer formed by polymerizing monomers in which Ar.sup.1 and Ar.sup.2 are the same.

[0103] In some embodiments, the conjugated polymer is a copolymer comprising two or more different repeat units. The copolymer may be formed by polymerizing monomers in which: at least one first monomer has an Ar.sup.1 group which is different from Ar.sup.2 of at least one second monomer; there are at least two different first monomers having different Ar.sup.1 groups; and/or there are at least two different second monomers having different Ar.sup.2 groups.

[0104] In some embodiments, the copolymer contains two different arylene repeat units. In some embodiments, the copolymer contains at least one arylene repeat unit and at least one repeat unit selected from heteroarylene repeat units and (hetero)arylamine repeat units.

[0105] Arylene repeat units of a copolymer preferably form 50-100 mol % of the repeat units of the polymer.

[0106] Exemplary heteroarylene repeat units include repeat units of formulae (V), (VI) and (VII):

##STR00006##

wherein R.sup.13 in each occurrence is as described above and f is 0, 1 or 2 if the heteroarylene repeat unit is a group Ar.sup.2 or at least one R.sup.13 is present (at least one f is 1) and is a polar substituent, e.g. an ionic substituent, if the heteroarylene repeat unit is a group Ar.sup.1.

[0107] (Hetero)arylamine repeat units of the conjugated polymer may have formula (VIII):

##STR00007##

wherein Ar.sup.8, Ar.sup.9 and Ar.sup.10 in each occurrence are independently selected from substituted or unsubstituted aryl or heteroaryl, g is 0, 1 or 2, preferably 0 or 1, and x, y and z are each independently 1, 2 or 3.

[0108] R.sup.9, which may be the same or different in each occurrence when g is 1 or 2, is preferably selected from the group consisting of alkyl, optionally C.sub.1-20 alkyl, Ar.sup.11 and a branched or linear chain of Ar.sup.11 groups wherein Ar.sup.11 in each occurrence is independently substituted or unsubstituted aryl or heteroaryl.

[0109] Any two aromatic or heteroaromatic groups selected from Ar.sup.8, Ar.sup.9, and, if present, Ar.sup.10 and Ar.sup.11 that are directly bound to the same N atom may be linked by a direct bond or a divalent linking atom or group. Preferred divalent linking atoms and groups include O, S; substituted N; and substituted C.

[0110] Ar.sup.8 and Ar.sup.10 are preferably C.sub.6-20 arylene, more preferably phenylene, that may be unsubstituted or substituted with one or more substituents, optionally one or more substituents selected from ionic and non-ionic substituents R.sup.13.

[0111] In the case where g=0, Ar.sup.9 is preferably C.sub.6-20 arylene, more preferably phenylene, that ay be unsubstituted or substituted with one or more substituents.

[0112] In the case where g=1, Ar.sup.9 is preferably C.sub.6-20 arylene, more preferably phenylene or a polycyclic arylene group, for example naphthalene, perylene, anthracene or fluorene, that may be unsubstituted or substituted with one or more substituents.

[0113] R.sup.9 is preferably Ar.sup.11 or a branched or linear chain of Ar.sup.11 groups. Ar.sup.11 in each occurrence is preferably phenyl that may be unsubstituted or substituted with one or more substituents.

[0114] Exemplary groups R.sup.9 include the following, each of which may be unsubstituted or substituted with one or more substituents, and wherein * represents a point of attachment to N:

##STR00008##

x, y and z are preferably each 1.

[0115] Ar.sup.8, Ar.sup.9, and, if present, Ar.sup.10 and Ar.sup.11 are each independently unsubstituted or substituted with one or more, optionally 1, 2, 3 or 4, substituents.

[0116] Substituents may independently be a group R.sup.13 as described above.

[0117] Preferred substituents of Ar.sup.8, Ar.sup.9, and, if present, Ar.sup.10 and Ar.sup.11 are C.sub.1-40 hydrocarbyl, preferably C.sub.1-20 alkyl.

[0118] Preferred repeat units of formula (VIII) include unsubstituted or substituted units of formulae (VIII-1), (VIII-2) and (VIII-3):

##STR00009##

[0119] In the case where the conjugated polymer is used as a light-emitting polymer, the or each repeat unit of the polymer may be selected to produce a desired colour of emission of the polymer.

[0120] The polystyrene-equivalent number-average molecular weight (Mn) measured by gel permeation chromatography of the polymers described herein may be in the range of about 110.sup.3 to 110.sup.8, and preferably 110.sup.4 to 510.sup.6. The polystyrene-equivalent weight-average molecular weight (Mw) of the polymers described herein may be 110.sup.3 to 110.sup.8, and preferably 110.sup.4 to 110.sup.7.

[0121] Polymers as described herein are suitably amorphous polymers.

[0122] Leaving Groups

[0123] Each X.sup.1 and X.sup.2 is individually selected from a halogen (preferably bromine or iodine) OSO.sub.2R.sup.a, boronic acid, and a boronic ester, wherein R.sup.a is an optionally substituted aryl or alkyl group.

[0124] OSO.sub.2R.sup.a is preferably tosylate or vitiate.

[0125] Exemplary boronic esters have formula (IX):

##STR00010##

wherein R.sup.6 in each occurrence is independently a C.sub.1-20 alkyl group, * represents the point of attachment of the boronic ester to an aromatic ring of the monomer, and the two groups R.sup.6 may be linked to form a ring. In a preferred embodiment, the two groups R.sup.6 are linked, e.g. to form:

##STR00011##

[0126] Solvent System

[0127] The first solvent, second solvent and, where present, water form a single phase. As used herein, a single phase refers to homogenous liquid phase. It does not include an emulsion.

[0128] The first solvent dissolves the first monomer.

[0129] According to some embodiments of the present disclosure the first solvent is a polar solvent. The polar solvent may or may not be a protic solvent. The second solvent may be selected from a C.sub.1-10 alcohol or diol, e.g. methanol, ethanol, methanol, butanol, propanol, tetrahydrofuran, acetic acid, acetone, dimethyl sulfoxide, N.N-dimethylformamide, acetonitrile, dimethoxyethane, and chlorinated solvents, e.g. dichloromethane or chloroform.

[0130] According to some embodiments of the present disclosure the second solvent is a non-polar solvent. The second solvent may be selected from a substituted or unsubstituted C.sub.6-15 alkane, a substituted or unsubstituted C.sub.4-15 aliphatic cyclic compound or a substituted or unsubstituted C.sub.6-15 aryl compound. The first solvent may be selected from, benzene; a substituted benzene e.g. benzene with one or more alkyl substituents such as xylene or toluene; and tetrahydrofuran.

[0131] A substituent of a substituted solvent as described herein may be selected from C.sub.1-C.sub.6 alkyl, C.sub.2-C.sub.6 alkenyl, C.sub.2-C.sub.6 alkenyl, C.sub.3-14 cyclic group, C.sub.1-6 alkoxy, C.sub.1-6 and alkylthio.

[0132] The second solvent dissolves the second monomer.

[0133] According to some embodiments of the present disclosure, the first solvent is miscible with water.

[0134] According to some embodiments of the present disclosure, the first solvent is miscible with the second solvent.

[0135] According to some embodiments of the present disclosure, the second solvent is immiscible with water. In these embodiments, the first solvent is provided in a sufficient amount to form a single phase with the first and second solvents.

[0136] In some embodiments of the present disclosure, formation of a polymerisation mixture comprises adding the second solvent to a mixture comprising the first and second monomers, and the first solvent.

[0137] In some embodiments of the present disclosure, formation of a polymerisation mixture comprises adding the second solvent to a mixture comprising the first and second monomers, the catalyst, water and the first solvent.

[0138] Catalyst

[0139] The polymerisation takes place in the presence of a palladium complex catalyst and a base.

[0140] The catalyst may be a palladium (0) or palladium (II) catalyst.

[0141] The catalyst may comprise phosphine ligands, e.g. ligands of formula PR.sup.3.sub.3 wherein each R.sup.3 is independently selected from C.sub.1-12 alkyl and aryl, preferably phenyl, which may be unsubstituted or substituted with one or more substituents, optionally one or more substituents selected from C.sub.1-12 alkyl and C.sub.1-12 alkoxy.

[0142] If the catalyst is a Pd (II) catalyst then anions include C.sub.1-10 alkoxy and halides, for example chloride bromide or iodide.

[0143] In some embodiments, the catalyst is provided in a preformed state in the polymerisation mixture at the start of polymerisation, in which the ligands, e.g. the phosphine ligands, are coordinated to the platium.

[0144] In some embodiments a ligand, e.g. phosphine, is provided with a platinum compound which itis not coordinated to, e.g. Pt(II)halide, at the start of the polymerisation.

[0145] The base may be an organic or inorganic base. Exemplary organic bases include tetra-alkylammonium hydroxides, carbonates and bicarbonates. Exemplary inorganic bases include metal (for example alkali or alkali earth) hydroxides, carbonates and bicarbonates.

[0146] The palladium complex catalyst may be a palladium (0) or palladium (II) compound.

[0147] Particularly preferred catalysts are tetrakis(triphenylphosphine)palladium (0) and palladium (II) acetate mixed with a phosphine,

[0148] A phosphine may be provided, either as a ligand of the palladium compound catalyst or as a separate compound added to the polymerisation mixture. Exemplary phosphines include triarylphosphines, for example triphenylphosphines wherein each phenyl may independently be unsubstituted or substituted with one or more substituents, for example one or more C.sub.1-5 alkyl or C.sub.1-5 alkoxy groups.

[0149] Particularly preferred are triphenylphospine and tris(ortho-methoxytriphenyl) phospine.

[0150] The polymer may be end-capped by addition of an end-capping reactant. Suitable end-capping reactants are aromatic or heteroaromatic materials substituted with only one leaving group. The end-capping reactants may include reactants substituted with a halogen for reaction with a boronic acid or boronic ester group at a polymer chain end, and reactants substituted with a boronic acid or boronic ester for reaction with a halogen at a polymer chain end. Exemplary end-capping reactants are halobenzenes, for example bromobenzene, and phenylboronic acid. End-capping reactants may be added during or at the end of the polymerisation reaction.

[0151] Applications

[0152] Polymers formed by the process described herein may be used in, without limitation, luminescent markers and organic electronic devices. A luminescent marker configured to bind to a biomolecule may contain a polymer as described herein, for example as disclosed in WO 2018/060722, the contents of which are incorporated herein by reference. Organic electronic devices include, for example, organic light-emitting devices, organic field-effect transistors, electrochromic colour-changing displays, chemical and biological sensors and organic photoresponsive devices, e.g. organic photovoltaic or photodetector devices. A polymer as described herein may be used as a conjugated polyelectrolyte.

POLYMER EXAMPLE 1

[0153] Polymer Example 1 was formed by polymerisation of Monomers 1 and 2, as illustrated in Scheme 1:

##STR00012##

[0154] Solubilities of Monomers 1 and 2 are given in Tables 1 and 2, respectively.

TABLE-US-00001 TABLE 1 Conc Toluene MeOH Water 0.1 mg/ml Soluble Soluble 1 mg/ml Soluble Soluble Insoluble 1 g/ml Soluble 2 g/ml Soluble 50 mg/ml Soluble 75 mg/ml soluble Not Soluble

TABLE-US-00002 TABLE 2 Conc Toluene MeOH Water 0.1 mg/ml Insoluble 1 mg/ml Insoluble Soluble 1 g/ml 2 g/ml 50 mg/ml Soluble Insoluble 75 mg/ml

[0155] A reaction vessel was charged with monomer 1 (1.18 g, 2.23 mmol) and monomer 2 (1.88 g, 2.25 mmol) and the vessel was purged with nitrogen overnight. Toluene (45 ml, degassed by sparging with nitrogen for 30 mins) and methanol (25 ml, degassed by sparging with nitrogen for 30 mins) was added to the reaction vessel. The mixture was stirred until a clear solution was obtained, and the resulting stirred mixture was degassed (30 min sparging with nitrogen). PdCl.sub.2[P(o-MeOPh).sub.3].sub.2 (6 mg, 0.0068 mmol) was added to the mixture which was stirred and heated (oil bath 90 C., internal temperature 60 C.). A degassed (sparged with nitrogen for 1 h) solution of sodium carbonate (1.121 g, 10.58 mmol) in water (11.21 ml) was added dropwise to the stirred, heated reaction mixture, After ca. 2 h additional degassed toluene (20 ml) and degassed methanol (20 ml) were added to the cloudy reaction mixture, which then cleared. After a further ca., 3 h, a dark colour was observed, so PdCl.sub.2[P(o-MeOPh).sub.3].sub.2 (6 mg, 0.0068 mmol) was added to the mixture and the reaction was continued for a further 14 h. To the stirred, heated reaction mixture, 2,6-dimethylphenyl boronic acid (0.135 g, 0.9 mmol), in a mixture of toluene (2 ml) and methanol (2 ml), and PdCl.sub.2[P(o-MeOPh).sub.3].sub.2 (0.0060 g, 0.0068 mmol) was added. The resulting solution was stirred and heated for 14 hours, then it was cooled to room temperature. The stirred mixture was heated (oil bath, 85 C.) and sodium diethyldithiocarbamate (2.5 g, 11.1 mmol) and water (14 mL) were added and the heated mixture stirred together for 2 h. The mixture was cooled to room temperature, and the aqueous phase removed. The polymer was dried in vacuo to yield a dark solid, which was dissolved in a mixture of toluene (50 ml) and methanol (50 ml). The polymer solution was passed through a short pad of Celite, and the polymer was eluted with further portions of toluene and methanol (200 ml). The polymer solution was evaporated to dryness in vacuo and then dissolved in a mixture of toluene (50 ml) and methanol (50 ml). The polymer solution was filtered through filter paper and precipitated from diethyl ether (600 ml, cooled) and washed with diethyl ether (350 ml). The resulting polymer was dried in a vacuum oven for 3 days to yield 1.36 g of a dark yellow solid.

[0156] With reference to FIG. 1, significant differences are observed between the infrared spectra of the monomers 1 and 2 and the product obtained by reaction of these monomers, indicating polymerisation of these monomers.

[0157] Polymer 1 has a solubility of at least 0.5 mg/ml in methanol.

POLYMER EXAMPLE 2

[0158] Polymer Example 2 was prepared according to the following reaction scheme:

##STR00013##

[0159] A reaction vessel was charged with monomer 3 (0.64 g, 0.619 mmol) and charged monomer 4 (0.73 g, 0.63 mmol) and the vessel was purged with nitrogen for 1 h. Toluene (20 ml, degassed by sparging with nitrogen for 30 mins) and methanol (20 ml, degassed by sparging with nitrogen for 30 mins) was added to the reaction vessel. The mixture was stirred until a clear solution was obtained, and the resulting stirred mixture was degassed (30 min sparging with nitrogen). Pd(OAc).sub.2 (4.2 mg, 0.02 mmol) and P(o-MeOPh).sub.3 (0.03 g, 0.08 mmol) were added to the mixture which was stirred and heated (oil bath 90 C.). A degassed (sparged with nitrogen for 1 h) solution of sodium carbonate (0.31 g, 2.94 mmol) in water (3.1 ml) was added dropwise to the stirred, heated reaction mixture. The reaction was stirred and heated. for 24 h, then 2,6-dimethylphenyl boronic acid (0.04 g, 0.25 mmol), in a mixture of toluene (2 ml) and methanol (2 ml), and Pd(OAc).sub.2 (4.2 mg, 0.02 mmol) and P(o-MeOPh).sub.3 (0.03 g, 0.08 mmol) were added. The resulting solution was stirred and heated for 14 hours, then cooled to room temperature. The aqueous phase was not separable, so the polymer was dried in vacuo to yield a dark solid, which was dissolved in a mixture of toluene (25 ml) and methanol (25 ml). The polymer solution was passed through a short pad of Celite, and the polymer was eluted with further portions of toluene and methanol (200 ml). The polymer solution was evaporated to dryness in vacuo and then dissolved in a mixture of toluene (20 ml) and methanol (20 ml). The polymer solution was filtered through filter paper and precipitated from diethyl ether (250 ml, cooled) and washed with diethyl ether (350 ml). The resulting polymer was dried in a vacuum oven for 24 h to yield 0.97 g of a dark grey brown solid.

[0160] Polymer 2 has a solubility of at least 1 mg/ml in both methanol and water.

[0161] With reference to FIG. 2, significant differences are observed between the infrared spectra of the monomers 3 and 4 and the product obtained by reaction of these monomers, indicating polymerisation of these monomers.

[0162] With reference to FIG. 3, the absorption spectra of Polymer Example 2 and Monomer 3 are very different, providing further evidence of polymerisation of the fluorene Monomers 3 and into polyfluorene Polymer Example 2.