WO2019012271A1

WO2019012271A1 - Conductive polymers

Info

Publication number: WO2019012271A1
Application number: PCT/GB2018/051960
Authority: WO
Inventors: Gregory G. Wildgoose; Andrew E. ASHLEY; James M. COURTNEY; Elliot J. LAWRENCE
Original assignee: Uea Enterprises Limited
Priority date: 2017-07-10
Filing date: 2018-07-10
Publication date: 2019-01-17
Also published as: GB201711058D0; GB2579298A; GB202001560D0

Abstract

Disclosed herein is a polymer comprising a conductive backbone having a plurality of Lewis pair side chain moieties thereon. Said Lewis pair side chain moieties each comprise a Lewis acid moiety (LA) comprising an electron pair acceptor, and a Lewis base moiety (LB) comprising an electron pair donor. The Lewis acid moieties of said Lewis pair side chain moieties are each electrically connected to the conductive backbone.

Description

CONDUCTIVE POLYMERS

Technical field

The present invention relates to conductive polymers. The invention relates more particularly, but not necessarily exclusively, to conductive polymers having improved charge storage capacity and/or improved internal ionic mobility. The invention relates yet more particularly, but not necessarily exclusively, to conductive polymers for use in electrodes.

Background

Conductive polymers, such as poly(pyrrole), poly(aniline), and poly(thiophene), find utility in electrical storage devices, such as batteries and supercapacitors. In particular, conductive polymers are typically low-cost and lightweight materials, offering numerous advantages such as chemical and electronic "tuning" of their properties, ease of monomer synthesis, simple chemical or electrochemical polymerisation methods, and enabling construction of mechanically flexible energy storage devices.

However, conductive polymers often suffer from rapid mechanical degradation (decreasing operational lifetimes) as a result of polymer swelling caused by intercalation/de-intercalation of ions during repeated charge-discharge cycles. Conductive polymers also often have lower specific capacitance values relative to other materials; large internal resistance/low intrinsic conductivity; and hindered diffusion of charge-balancing counter ions throughout the polymer layer that limits both rates of charging or discharging, and also the maximum useful polymer film thickness that can be grown.

It is desirable to provide an improved conductive polymer, battery, capacitor, and/or method of producing a polymer; and/or to otherwise to obviate and/or mitigate one or more of the

disadvantages with known conductive polymers, batteries, capacitors, uses and/or methods of producing polymers, whether identified herein or otherwise.

Summary

The present invention is defined in the accompanying claims. Therefore, in accordance with the present invention there is provided a polymer comprising a conductive backbone having a plurality of Lewis pair side chain moieties thereon, said Lewis pair side chain moieties each comprising: a Lewis acid moiety (LA) comprising an electron pair acceptor, and a Lewis base moiety (LB) comprising an electron pair donor, wherein the Lewis acid moieties of said Lewis pair side chain moieties are each electrically connected to the conductive backbone.

There is also provided a compound ha

wherein X^LA is an electron pair acceptor;

wherein X^LB is an electron pair donor;

wherein each R^A is, independently, selected from optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclic and heterocyclic; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted 5- to 6-membered aromatic or 4- to 8-membered non- aromatic ring; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6- membered aromatic or 4- to 8-membered non-aromatic ring;

wherein each R^B is, independently, selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, heteroaryl, carbocyclic and heterocyclic, and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted fused 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S; and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring; and

with the proviso that the compound is not:

F

There is also provided a use of a compound having the formula (II):

wherein X^LA is an electron pair acceptor;

wherein X^LB is an electron pair donor;

wherein each R^B is, independently, selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, heteroaryl, carbocyclic and heterocyclic, and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted fused 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S; and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring.

There is also provided a polymer comprising a conductive backbone having a plurality of Lewis pair side chain moieties thereon, said polymer being formed from polymerisation of one or more monomers, the one or more monomers comprising one or more compounds having the formula

(Ill):

wherein X^LA is an electron pair acceptor;

wherein X^LB is an electron pair donor;

wherein each R^A is, independently, selected from optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclic and heterocyclic; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted 5- to 6-membered aromatic or 4- to 8-membered non- aromatic ring; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6- membered aromatic or 4- to 8-membered non-aromatic ring; and

There is also provided an electrode comprising a polymer of the invention as set out above, said polymer being present as one or more layers on the surface of said electrode

There is also provided a battery or capacitor comprising one or more polymers of the invention as set out above.

There is also provided a battery or capacitor comprising one or more electrodes of the invention as set out above. There is also provided a method of producing a polymer, comprising: polymerising one or more compounds of the invention as set out above. Definitions

The meanings of terms used in the specification of the present application will be explained below, and the present invention will be described in detail.

In general terms, a polymer is formed from multiple monomer repeat units, such as 3 or more, 5 or 10 or more.

The term "aliphatic" means a substituted or unsubstituted straight-chain, branched or cyclic hydrocarbon, which is completely saturated or which contains one or more units of unsaturation, but which is not aromatic. Aliphatic groups include substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl, alkynyl groups and hybrids thereof, such as (cycloalkyi )alkyl,

(cycloalkenyl)alkyl or (cycloalkyl)alkenyl. An aliphatic group may have 1 to 12, 1 to 8, 1 to 6, or 1 to 3 carbons. For example, C1-3 aliphatic encompasses straight chain and branched C1-3 alkyl, alkenyl and alkynyl and cyclopropyl. The term "heteroaliphatic" means an aliphatic group in which one or more carbon atom is replaced by a heteroatom. The term "heteroatom" refers to nitrogen (N), oxygen (O), or sulfur (S).

The term "alkyl" means a straight-chain or branched hydrocarbon, which is completely saturated. A substituted alkyl is an alkyl group in which one or more hydrogen atoms is replaced with a substituent (e.g. a halogen to form a haloalkyl).

The term "alkenyl" means a straight-chain or branched hydrocarbon, which contains at least one double bond.

The term "alkynyl" means a straight-chain or branched hydrocarbon, which contains at least one triple bond.

The term "carbocyclyl" "carbocyclic" refers to a cyclic aliphatic group and includes, for example, cycloalkyi moieties. A carbocyclic group may comprise at least three, e.g. up to ten, carbon atoms in a ring configuration. The term "heterocyclic" or "heterocyclyl" refers to a saturated (e.g. heterocycloalkyl) or unsaturated (e.g. heteroaryl) heterocyclic ring functional groups comprising at least three, e.g. up to ten, carbon atoms in a ring configuration, with at least one of the carbons replaced with a non-carbon atoms, preferably selected from nitrogen, oxygen, phosphorous silicon and sulphur. Heterocyclyl may refer to a saturated or unsaturated, five to ten membered ring or ring system and optionally a saturated or unsaturated, five or six membered ring.

The term "aryl" refers to a Ce-14 (preferably Ce-io) aromatic hydrocarbon, comprising one to three rings, each of which is optionally substituted. Aryl groups include, without limitation, phenyl, naphthyl, and anthracenyl. Two adjacent substituents on an aryl ring, taken together with the intervening ring atoms, may form an optionally substituted fused 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S. Thus, the term "aryl", as used herein, includes groups in which an aromatic ring is fused to one or more heteroaromatic, cycloaliphatic, or heterocyclic rings, where the radical or point of attachment is on the aromatic ring.

The terms "heteroaryl" and "heteroaromatic" refer to an aromatic group having 5 to 14 ring atoms, preferably 5, 6, 9, or 10 ring atoms and having, in addition to carbon atoms, from one to four heteroatoms as ring atoms. The term "heteroatom" refers to N, O, or S. Two adjacent substituents on the heteroaryl, taken together with the intervening ring atoms, may form an optionally substituted fused 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S. Thus, the terms "heteroaryl" and "heteroar-", as used herein, also include groups in which a heteroaromatic ring is fused to one or more aromatic, cycloaliphatic, or heterocyclic rings, where the radical or point of attachment is on the heteroaromatic ring.

The term "substituted", as used herein, means that one or more hydrogen radicals of a designated moiety is replaced with one or more radicals of a specified substituent, provided that the substitution results in a stable or chemically feasible compound. The number of radicals that may be replaced equals from one to the maximum number of substituents possible based on the number of available bonding sites. By way of example, if a methyl moiety is substituted, it may be substituted by 1 , 2 or 3 radicals of the specified substituent. Thus, the moiety may, for example, be -CH₂F, -CHF₂ or -CF₃. Unless otherwise indicated, where multiple substituents are present, substituents may be either the same or different.

Suitable substituents include one or more moieties selected from halogen, -NO2, -CN, -R^s, -C(R^S)=C(R^S)₂, -C≡C-R^S, -OR^s, -SR^S, -S(0)R^s, -S0₂R^s, -S0₃R^s, -S0₂N(R^s)₂, -N(R^S)₂, -[N(R^S)₃]⁺, -NR^sC(0)R^s, -NR^sC(0)N(R^s)₂, -NR^sC0₂R^s, -NR^sS0₂R^s, -NR^sS0₂N(R^s)₂, -0-C(0)R^s, -0-C0₂R^s, -OC(0)N(R^s), -C(0)R^s, -C0₂R^s, -C(0)N(R^s)₂, -Si(R^s)₃, -P(R^S)₂, -[P(R^S)₃]⁺, -P(0)(R^s)₂, -P(0)(OR^s)₂, -0-P(0)-OR^s, wherein R^s, independently, is hydrogen or an aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, or two occurrences of R^' are taken together with their intervening atom(s) to form a 5-7-membered aromatic, heteroaromatic, cycloaliphatic, or heterocyclic ring.

Group 13 elements comprise boron (B), aluminium (Al), gallium (Ga), indium (In) and thallium (Tl).

Group 15 elements comprise nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi).

As used herein, the term "electrically connected" as applied to a Lewis pair side chain moieties comprising an electron pair acceptor means that an electrical current can pass via the conductive backbone to the electron pair acceptor. The conductive backbone may, for example, be a conjugated system adjacent an electron pair acceptor, and a current may pass through the conjugated system of the conductive backbone to the electron pair acceptor, thereby forming a delocalised system between the backbone.

As used herein, the term "comprises" means "includes, but is not limited to".

As used herein, the phrase "consist essentially of as applied to a designated component is used herein to denote that the designated component is present, and that one or more specific further components can be present, as long as those further components do not materially affect the essential characteristic(s) of the designated component. As applied to a polymer being formed from polymerisation of one or more monomers, for example, it will be appreciated that the

"essential characteristic" of those monomers is to provide for the formation of a polymer. If a mixture is to "consist essentially of" such monomers, then the mixture should not comprise further components which may preclude and/or substantially impact such formation.

Suitably, the term "consist essentially of may be interpreted such that the subject is primarily composed of a designated component (or components; i.e. there is a majority of that

component(s)). Suitably, the subject comprises greater than or equal to about 85% of the designated component(s), such as greater than or equal to about 90%, such as greater than or equal to about 95%, such as greater than or equal to about 98%, such as greater than or equal to about 99%, such as about 100% (i.e. the subject consists of the designated component(s)).

A "homopolymer" is formed of a single monomer. A "copolymer" is formed of two or more different monomer (e.g. three or more) units. A copolymer may be a random copolymer, a statistical copolymer, graft copolymer, an alternating copolymer, or a periodic copolymer.

Detailed description

According to the present invention, there is provided a polymer comprising a conductive backbone having a plurality of Lewis pair side chain moieties thereon, said Lewis pair side chain moieties each comprising: a Lewis acid moiety (LA) comprising an electron pair acceptor, and

a Lewis base moiety (LB) comprising an electron pair donor, wherein the Lewis acid moieties of said Lewis pair side chain moieties are each electrically connected to the conductive backbone.

The conductive polymers of the present invention find utility in electrical storage devices, such as batteries and supercapacitors. Incorporation of Lewis acidic groups onto the backbone confers many advantageous properties to the resulting conducting polymers such as: improved specific charge storage capacity; tuneable conducting windows and variable redox voltages; and the ability to generate a more open polymer structure with higher internal ionic mobility, allowing freer diffusion of ions during repeated charging/discharging cycles.

The electron pair acceptor may comprise a Group 13 element, such as boron or aluminium. The Group 13 element may be boron.

The electron pair acceptor may be bonded to one or more (e.g. two) R^A moieties, the or each R^A being independently selected from optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclic and heterocyclic; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6-membered aromatic or 4- to 8- membered non-aromatic ring.

Selection of the one or more R^A moieties to which the electron pair acceptor is bonded facilitates tuning of the polymer conducting window and/or redox voltages. In particular, tuning may be achieved by selecting one or more R^A moieties which have electron withdrawing properties.

Moreover, selecting one or more R^A moieties based on the strength of their electron withdrawing properties may further facilitate tuning of the polymer conducting window and/or redox voltages.

Additionally, selection of the one or more R^A moieties to which the electron pair acceptor is bonded enables the structure of the polymer to be tailored. By way of example, selection of a larger R^A moiety (or moieties) may produce a more "open" structure in the polymer. This enables polymers many tens of microns thick to be produced that remain conductive and accessible to ions to which the polymer may be exposed (e.g. in an electrolyte of a battery). The more "open" structure also reduces mechanical degradation of the polymer during repeated charging/discharging cycles (e.g. in the context of a battery). This in turn results in a conducting polymer material with a significantly improved operational lifetime within a charge storage device compared to conventional polymer materials.

The electron pair acceptor may be bonded to two R^A moieties. Optionally, said R^A moieties may be the same.

The one or more R^A moieties may be substituted by one or more of moieties independently selected from an optionally substituted aliphatic (e.g. CF3), heteroaliphatic, aromatic or heteroaromatic moiety, halogen, -N0₂, -CN, -C(R^')=C(R^')₂, -C≡C-R , -OR^', -SR\ -S(0)R', -S0₂R', -SO3R, -S0₂N(R^')₂, -N(R , -[N(R^')₃]⁺, -NR^'C(0)R, -NR^'C(0)N(R)₂, -NR CO2R , -NRS0₂R', -NR^'S0₂N(R^')₂, -0-C(0)R, -O-CO2R^', -OC(0)N(R), -C(0)R , -CO2R, -C(0)N(R^')₂, -Si(R^')₃, -P(R)₂, -[P(R')3]⁺, -P(0)(R^')₂, -P(0)(OR^')₂, -0-P(0)-OR , wherein R^', independently, is hydrogen, halogen or aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, or two occurrences of R are taken together with their intervening atom(s) to form a 5-7-membered aromatic, heteroaromatic, cycloaliphatic, or heterocyclic ring, optionally wherein each R is, independently, substituted.

The or each R^A may be independently selecte

wherein each R^1a is independently selected from an optionally substituted aliphatic (e.g. CF3), heteroaliphatic, aromatic or heteroaromatic moiety, halogen, -NO2, -CN, -C(R^')=C(R^')₂, -OC-R^', -OR^', -SR\ -S(0)R', -SO2R', -SO3R , -S0₂N(R , -N(R^')₂, -[N(R^')₃]⁺, -NR^'C(0)R^',

-NR^'C(0)N(R^')₂, -NRC0₂R , -NR^'S0₂R', -NR^'S0₂N(R^')₂, -0-C(0)R , -0-C0₂R , -OC(0)N(R ), -C(0)R^" -C0₂R, -C(0)N(R)₂, -Si(R)₃, -P(R^')₂, -[P(R^')₃]⁺, -P(0)(R)₂, -P(0)(OR)₂, -0-P(0)-OR, wherein R , independently, is hydrogen, halogen or aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, or two occurrences of R^' are taken together with their intervening atom(s) to form a 5-7-membered aromatic, heteroaromatic, cycloaliphatic, or heterocyclic ring, optionally wherein each R is, independently, substituted;

wherein n is selected from 0, 1 , 2, 3, 4 or 5.

Optionally, each R , independently, is substituted. n may be 1 , 2, 3 or 5. Optionally, n is 5.

The or eac ^A may independentl

wherein the or each R , independently, is as defined above.

The or each R ^a may be an electron withdrawing group.

The or each R ^a may, independently, be selected from halogen, -C(0)R , -C0₂R , -C(0)N(R^')₂, halogen substituted aliphatic, -CN, -SO3R^', -[N(R^')₃]⁺, or -N0₂.

The or each R ^a may be a halogen, such as F, CI, Br. Optionally the or each R ^a is F or CI.

Optionally, the or each R^1a is F.

The or each R^A may independently be selected from halophenyl, such as pentahalophenyl (e.g. pentafluorophenyl or pentachlorophenyl); 3,5 bis(trifluoromethyl)phenyl; 1 ,3,5 trimethyl phenyl; or wherein two said R^A moieties form a bridged carbocycle bridged by the electron pair acceptor to which they are attached, optionally wherein the bridged carbocycle is a bridged cyclooctane.

The or each R^A may be pentafluorophenyl.

The or each R^1a may be halogen substituted aliphatic. Optionally, the or each R^1a is trihalomethyl; optionally trifluoromethyl or trichloromethyl. The or each R ^a may be trifluoromethyl. The electron pair donor may be a Group 15 element, such as nitrogen or phosphorus. Optionally the Group 15 element is nitrogen.

The backbone may comprise a conjugated system.

The polymer may have the formula (I):

wherein each R^B is independently selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, heteroaryl, carbocyclic and heterocyclic, and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted fused 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S; and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring;

wherein X^LB is the electron pair donor as defined above;

wherein LA is the Lewis acid moiety as defined above; and

wherein m is an integer of at least about 3; optionally greater than about 10.

The one or more R^B moieties may be substituted by one or more of moieties independently selected from an optionally substituted aliphatic (e.g. CF3), heteroaliphatic, aromatic or

heteroaromatic moiety, halogen, -N0₂, -CN, -C(R")=C(R")₂, -C≡C-R", -OR", -SR", -S(0)R",

-SO2R", -SO3R", -S0₂N(R")₂, -N(R")₂, -[N(R")₃]⁺,-NR"C(0)R", -NR"C(0)N(R")₂, -NR"C0₂R", -NR"S0₂R", -NR"S0₂N(R")₂, -0-C(0)R", -0-C0₂R", -OC(0)N(R"), -C(0)R", -C0₂R", -C(0)N(R")₂, -Si(R")₃, -P(R")_2> -[P(R")3]⁺, -P(0)(R")₂, -P(0)(OR")₂, -0-P(0)-OR", wherein R", independently, is hydrogen, halogen or aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, or two occurrences of R" are taken together with their intervening atom(s) to form a 5-7-membered aromatic, heteroaromatic, cycloaliphatic, or heterocyclic ring, optionally wherein each R" is, independently, substituted.

The one or more R^B moieties may be hydrogen. Optionally, both R^B moieties are hydrogen. The backbone may comprise pyrrole and/or thiophene moieties. The backbone may comprise pyrrole moieties.

A poly(pyrrole) backbone allows for donor-acceptor interactions between an adjacent lone pair on the nitrogen of the pyrrole ring and a vacant pz orbital on the electron pair acceptor. Similar interactions may exist with other moieties on the backbone.

According to the present invention there is also provided a compound having the formula (II):

wherein X^LA is an electron pair acceptor as defined above;

wherein X^LB is an electron pair donor as defined above;

Optional features set out above in respect of the polymer of the invention also apply, mutatis mutandis, to the compound. In particular, optional features set out above in respect of the electron pair acceptor, electron pair donor, R^A and R^B also apply to the compound.

Optionally, the compound is not:

The compound may be selected from:

The compound may be:

The compound may be:

There is also provided a use of a compound having the formula (II):

wherein X^LA is an electron pair acceptor;

wherein X^LB is an electron pair donor;

wherein each R^B is, independently, selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, heteroaryl, carbocyclic and heterocyclic, and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted fused 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S; and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring;

in the formation of a conductive polymer.

Optional features set out above in respect of the polymers and compounds of the invention also apply, mutatis mutandis, to the use. In particular, optional features set out above in respect of the electron pair acceptor, electron pair donor, R^A and R^B also apply to the use, as do specifically illustrated compounds.

According to the present invention there is also provided a polymer comprising a conductive backbone having a plurality of Lewis pair side chain moieties thereon, said polymer being formed from polymerisation of one or more monomers, the one or more monomers comprising one or more compounds having the formula (III):

wherein X^LA is an electron pair acceptor as defined above;

wherein X^LB is an electron pair donor as defined above;

wherein each R^B is, independently, selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, heteroaryl, carbocyclic and heterocyclic, and/or wherein two R moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted fused 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S; and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring.

Optional features set out above in respect of the polymer and the compound of the invention, also apply, mutatis mutandis, to the polymer in the paragraph above. In particular, optional features set out above in respect of the electron pair acceptor, electron pair donor, backbone, R^A and R^B also apply to this polymer as well.

The one or more compounds may comprise:

The one or more compounds may comprise:

The one or more compounds may comprise:

The one or more compounds may comprise:

The one or more compounds may comprise:

The one or more monomers may further comprise pyrrole and/or thiophene. Optionally, the one or more monomers further comprise pyrrole.

The one or more monomers may further comprise pyrrole and/or thiophene, optionally pyrrole.

The one or more monomers may consist essentially of the compound(s). The polymer may be a homopolymer or a co-polymer. Optionally, the polymer is a homopolymer.

According to the present invention there is also provided an electrode comprising a polymer as set out in the summary above, said polymer being present as one or more layers on the surface of said electrode

The electrode may comprise a carbon electrode, such as glassy carbon, graphite plate, or carbon fibre cloth.

According to the present invention there is also provided a battery or capacitor comprising one or more polymers of the invention as set out above.

There is also provided a battery or capacitor comprising one or more electrodes as set out in the summary above.

According to the present invention there is also provided a method of producing a polymer, comprising: polymerising one or more compounds of the invention as set out above. Polymerising may be conducted by electropolymerisation.

Polymerising may be conducted under non-aqueous conditions (e.g. an organic, optionally halogenated solvent, such as dichloromethane).

Brief description of the figures

The present invention will now be described, by way of example, with reference to the

accompanying drawings in which:

Figure 1 shows a series of cyclic voltammograms showing the oxidation of specific monomer compounds.

Figure 2 shows X-ray crystallographic structures and resonance structure of specific compounds.

Figure 3 shows molecular orbitals of specific compounds. Figure 4 shows overlaid cyclic voltammograms of specific compounds.

Figure 5 shows EQCM massogram data for specific polymers and mass added per polymerisation cycle.

Figure 6 shows an SEM image corresponding EDX analysis for a specific polymer.

Figure 7 shows a comparison of charge storage capacity for specific polymers.

Figure 8 shows galvanostatic charge-discharge cycles for specific polymers.

Figure 9 shows images of a polymer-modified carbon cloth supercapacitor assembly.

Examples

The following examples are provided for illustrative purposes to describe the invention in more detail.

Chemical reagents were purchased from Sigma Aldrich (Gillingham, UK) and used without further purification unless stated otherwise. All synthetic reactions and manipulations were performed under a rigorously dry inert N2 Ar atmosphere using standard Schlenk-line techniques on a dual manifold vacuum/inert gas line or an MBraun glovebox. Anhydrous solvents were dried by reflux over appropriate drying agents and were collected by distillation under an inert atmosphere. All solvents were sparged with nitrogen gas to remove any trace of dissolved oxygen and stored in ampoules over activated 4A molecular sieves prior to use. Pyrrole was freshly distilled prior to use, and stored under an inert atmosphere below 4 °C.

NMR Spectra were obtained on a Bruker Advance DPX-500 spectrometer; for H spectra residual proi/o-solvent was used as an internal standard; for C the solvent resonance(s) were used as an internal standard; for ⁹F spectra CFCI3 was used as an external standard; for ¹B spectra BF3-Et20 was used as an external standard.

Mass spectrometry and elemental analysis was performed by the EPSRC Mass Spectrometry Service at the University of Swansea and by the Elemental Analysis Service at London

Metropolitan University respectively. X-ray crystallography was recorded for single crystals of (NC4H₄)B(C6Cl5)2 grown from a saturated n-hexane solution at -25 °C. Suitable crystals were selected, encapsulated in a viscous perfluoropolyether, and mounted on an Agilent Technologies Xcalibur-3 single crystal X-ray diffractometer using Mo Ka radiation where the crystals were cooled to 140 K during data collection and a full sphere of data collected. The data was reduced and an absorption correction performed using Agilent Technologies CrysAlisPro. Using Olex2, the structure was solved with ShelXS version 2013/1 using direct methods, and then refined with the ShelXL version 2014/7 refinement program using least squares minimisation.

Single crystals of monomer (NC H4)B{2,4,6-(CH3)3C6H2}2 (4) were similarly grown, selected, encapsulated in a viscous perfluoropolyether, and mounted on an Agilent Technologies Xcalibur-3 single crystal X-ray diffractometer using Mo Ka radiation where the crystals were cooled to 140 K during data collection and a full sphere of data collected. The data was reduced and an absorption correction performed using Agilent Technologies CrysAlisPro. Data collection and processing was performed at the UK National Crystallographic Service at the University of Southampton. Using Olex2, the structure was solved and space group assigned with SuperFlip/EDMA using charge flipping / solved with ShelXS version 2013/1 or SheIXT version 2014/5 using direct methods, and then refined with the ShelXL version 2016/6 refinement program using least squares minimisation.

Electrochemical quartz crystal microbalance (EQCM) measurements were performed using a potentiostat-d riven EQCM module (Metrohm) equipped with a carbon-coated 6MHz quartz AT-cut crystal electrode (ø = 6.0 mm).

All electrochemical measurements were performed under an anhydrous, inert, Ar atmosphere inside a glovebox (MBraun, H2O < 0.1 ppm, 0∑< 0.1 ppm) using a Metrohm Autolab PGSTAT302N computer-controlled potentiostat (Metrohm, Utrecht, The Netherlands), equipped with a FRA32M module for electrochemical impedance spectroscopy (EIS) studies, and linked to a computer running NOVA software {v. 1.1 1 ).

The electrolyte comprised rigorously anhydrous dichloromethane (DCM) containing 0.05 M

[ⁿBu4N][B(C6F₅)4]. All voltammetric and EIS studies employed a three-electrode configuration using a bright Pt gauze counter electrode (99.99%, Alfa Aesar), a silver wire pseudo-reference electrode (99.99%, Alfa Aesar), and a graphitic carbon working electrode comprised from one of the following materials: a glassy carbon electrode (GC, 0 3mm, 99.99% Type II Alfa Aesar); a POCO graphite plate (GP, 2 x 25 x 15 mm POCO Graphite AXF-5Q Specialty Graphite, MatWeb LLC ); a high surface area carbon fibre cloth electrode (CC, 356 μηι thickness, 1 .0 x 2.0 mm geometric surface area, AvCarb1071 HCB, Fuel Cell Store). The GC electrodes were polished sequentially with 15, 9, 6, 3, and 1 μιη diamond pastes

(Kemmet) and finally 0.05 μιτι alumina slurry (Buehler), before being thoroughly dried under vacuum prior to use. The silver pseudo-reference electrode potential was referenced at the end of each experiment to the [Cp2Fe]^{0 +} redox couple (unless stated otherwise).

Cyclic voltammetric experiments were performed with a step voltage of 2 mV and a voltage scan rate of 100 mVs ¹ unless stated otherwise.

Galvanostatic charge/discharge curves were recorded using a current ramp of 500 μΑ.β^"1 (unless stated otherwise) with a pre-determined cut-off voltage to end the cycle (stated in text). Each charge/discharge cycle commenced by holding at the open circuit potential for 30 s, followed by charging for 30 s and finally discharging for a further 30 s. For long-term cycling studies, a cut-off voltage of 1.0 V was used and an open circuit potential determination was not performed between each cycle. Separate studies to ascertain the specific capacitance and maximum charging voltage of each device used a 30 s charge/discharge time per cycle rather than a specific cut-off voltage.

Scanning electron microscopy (SEM) measurements were performed using a JSM 5900 LV scanning electron microscope (JEOL) equipped with an INCA energy dispersive X-ray

spectrometer (EDX, Oxford Instruments) to enable surface elemental mapping. Cross-sections taken through specially constructed GC electrodes modified with either poly(pyrrole) or poly(1 ) were mounted onto SEM sample stubs using silver ink ( S Components) to form a conducting connection to the rear of each sample.

Computational calculations were performed using density functional theory (DFT) using the Gaussian 09 (revision C.01 ) computational package. Calculations were carried out using the three-parameter exchange functional of Becke (B3) with the correlation functional of Lee, Yang, and Parr (LYP), B3LYP, [Becke, A. D., Density-functional thermochemistry. III. The role of exact exchange. J Chem Phys 1993, 98, 5648-5652 & Lee, C; Yang, W.; Parr, R., Development of the Colle- Salvetti correlation energy formula into a functional of the electron density. Phys Rev B 1988, 37, 785-789] together with applying the 6-31 1 +G(d,p) basis set for all atoms. Structures were geometry optimised in the gas phase with the default convergence criteria, and confirmed as minima through frequency calculations. Natural bond order analysis was performed using

Gaussian NBO (version 3.1 ).

Monomer synthesis

Monomers 1 to 6 were synthesised according to the procedure outlined below.

Example 1: synthesis of (NC₄H4)B(CeF₅)2 1

1 was synthesised from B(C6F₅)2FOEt2 and Li(NC4H4), following the procedure outlined in Kumar, N. A.; Choi, H. J.; Bund, A.; Baek, J.-B.; Jeong, Y. T., Electrochemical supercapacitors based on a novel graphene/conjugated polymer composite system. J Mater Chem 2012, 22, 12268-12274. H NMR (500.2 MHz, CDCI3, 25 °C, δ): +6.93 (m, 2H, pyrrolyl 2,5-H), +6.54 (m, 2H, pyrrolyl 3,4- H); ¹¹B NMR (160.5 MHz, CDCI3, 25 °C, δ): +41.8 (br.s); ¹³C{ H} NMR (125.8 MHz, CDCI3, 25 °C, δ): +146.7 (br.d, ¹J_CF * 247 HZ, Ar^F5 o-C), +143.1 (br.d, ¹J_CF = 263 Hz, Ar^F5 p-C), +137.5 (br.d, J_CF * 252 Hz, Ar^F5 m-C), +127.2 (s, pyrrolyl 2,5-C), +1 17.8 (s, pyrrolyl 3,4-C); ¹⁹F NMR (470.7 MHz, CDCI3, 25 °C, δ): -130.0 (br.d, 4F, Ar^F5 o-F), -148.6 (t, ³JFF = 19.9 Hz, 2F, Ar^F5 p-F), -160.0 (m, 4F, Ar^F5 m-F).

Example 2: synthesis of (NC₄H4)B(C₆Cl5)2 2

A suspension of lithium pyrrol-1-ide (0.15 g, 2.0 mmol) in 50 cm³ Et₂0 was added (via cannula) to a solution of B(C6Cl5)₂CI (1.09 g, 2.0 mmol) in 40 cm³ toluene at -77 °C (dry ice//so-propanol). After 1 hour at -77 °C, the reaction mixture was allowed to warm to room temperature and stirred for ca. 18 hours. Volatiles were removed in vacuo, the product extracted into a minimum volume toluene, and precipitated after cooling to -25 °C as a light yellow powder, which was isolated by filtration and dried in vacuo. Yield 0.47 g (0.9 mmol, 45%). H NMR (500.2 MHz, CDCI3, 25 °C, δ): +6.77 (m, 2H, pyrrolyl 2,5-H), +6.46 (m, 2H, pyrrolyl 3,4- H); ¹¹B NMR (160.5 MHz, CDCI3, 25 °C, δ): +42.5 (br.s); ¹³C{ H} NMR (125.8 MHz, CDCI3, 25 °C, δ): +136.2 (br.m, Ar^cl5 /-C), +135.9 (s, Ar^cl5), +132.6 (s, Ar^cl5), +132.2 (s, Ar^cl5), +126.4 (s, pyrrolyl 2,5-C), +117.1 (s, pyrrolyl 3,4-C). HR S-ASAP (m/z): [M+H]⁺ calc. for Ci_eH₅BiClioNi⁺, 575.7345; found, 575.7353. Elemental analysis (calc. for C₁₆H₄B₁Cli₀N₁): C 33.45 (33.38), H 0.79 (0.70), N 2.34 (2.43)

Example 3: synthesis of (NC₄H₄)B{3,5-(CF3)2C6H3}2 3

A solution of B{3,5-(CF3)2C₆H₃}2CI (1.66 g, 3.52 mmol) in 30 cm³ Et₂0 was added (via cannula) to a suspension of lithium pyrrol-1-ide (0.26 g, 3.49 mmol) in 15 cm³ Et∑0, and stirred at +20 °C for 1 hour before all volatiles were removed in vacuo. The product was extracted into 45 cm³ petroleum ether, and isolated by filtration (via cannula) as a yellow solution; from which volatiles were removed in vacuo, to give a crude yellow oil. This was re-dissolved in 5 cm³ petroleum ether and cooled at -25 °C. While still cold the yellow solution was isolated by filtration (via cannula) from the precipitated impurities, volatiles were then removed in vacuo, to give 3 as a yellow oil. Yield 1.14 g (2.27 mmol, 65%).

¹H NMR (500.2 MHz, CDCI₃, 25 °C, δ): +8.11 (s, 2H, Ar^F6 p-H), +8.02 (s, 4H, Ar^F6 o-H), +6.98 (m, 2H, pyrrolyl 2,5-H), +6.62 (m, 2H, pyrrolyl 3,4-H); ¹¹B NMR (160.5 MHz, CDCI3, 25 °C, δ): +46.5 (br.s); ¹³C{¹H} NMR (125.8 MHz, CDCI3, 25 °C, δ): +135.4 (br.q, ³J_CF - 3.6 Hz, Ar^F6 o-C) +131.5 (q, ²JCF = 33 Hz, Ar^F6 m-C), +127.5 (s, pyrrolyl 2,5-C), +125.1 (sept., ³J_CF = 3.6 Hz, Ar^F6 p-C), +123.25 (q, ¹J_CF = 273 Hz, Ar^F6 m-CF₃), +116.9 (s, pyrrolyl 3,4-C); ¹⁹F NMR (470.7 MHz, CDCI3, 25 °C, δ): -62.9 (s, 12F, Ar^F6 m-CF₃). HRMS-ASAP/APCI (m/z): [M+H]⁺ calc. for C₂oHiiBiFi₂Ni⁺, 503.0824; found, 503.0816. Elemental analysis (calc. for C₂oHi₀BiFi₂Ni): C 48.06 (47.73), H 1.97 (2.00), N 2.79 (2.78)

Example 4: synthesis of (NC4H₄)B{2,4,6-(CH3)3C₆H2}2 4

B{2,4,6-(CH₃)3C₆H2}2C Lithium mesityl (3.16 g, 25.1 mmol) was suspended in 15 cm³ toluene, BCI₃ (12.5 cm³, 1.0 mmol.crrf³ in heptane) was added, and the mixture stirred for 2 hours at +20 °C followed by 18 hours at +90 °C. Once cooled the reaction mixture was filtered (via cannula) to isolate a pale yellow solution, from which volatiles were removed in vacuo, to give a pale yellow oil, which crystallised as a white solid over a few days at +20 °C. Yield 2.64 g (9.27 mmol, 74%).

¹H NMR (500.2 MHz, C₆D₆, 25 °C, δ): +6.67 (s, 4H, Mes m-H), +2.32 (s, 6H, Mes p-Me), +2.07 (s, 12H, Mes o-Me); ¹B NMR (160.5 MHz, C₆D₆, 25 °C, δ): +70.2 (br.s).

A solution of B{2,4_I6-(CH3)₃C₆H₂}2CI (1.37 g, 3.55 mmol) in 20 cm³ Et₂0 was added (via cannula) to a suspension of lithium pyrrol-1-ide (0.26 g, 3.55 mmol) in 20 cm³ Et^O, and stirred at +20 °C for 18 hours. Volatiles were removed in vacuo, to give a pale brown solid; this was extracted into 10 cm³ petroleum ether, filtered via cannula, concentrated in vacuo to ca. 2 cm³, and cooled at -25 °C. While still cold the precipitated product was isolated by filtration (via cannula) then dried in vacuo, to give a pale orange solid. Yield 0.66 g (2.08 mmol, 59%). 4 May be further purified via sublimation at +125 °C / 10^~1 mbar if required.

Ή NMR (500.2 MHz, CDCI₃, 25 °C, δ): +6.79 (s, 4H, Mes m-H), +6.76 (m, 2H, pyrrolyl 2,5-H), +6.32 (m, 2H, pyrrolyl 3,4-H), +2.27 (s, 6H, Mes p-Me), +2.07 (s, 12H, Mes o-Me); B NMR (160.5 MHz, CDC , 25 °C, δ): +52.1 (br.s); ¹³C{ H} NMR (125.8 MHz, CDCI₃, 25 °C, δ): +141 .6 (s, Mes o-C), +138.9 (s, Mes p-C), +128.2 (s, Mes m-C), +126.3 (s, pyrrolyl 2,5-C), +114.4 (s, pyrrolyl 3,4-C), +22.4 (s, Mes c-Me), +21 .2 (s, Mes p-Me). HRMS-ASAP (m/z): [M+H]⁺ calc. for C₂2H₂7BiNi⁺, 316.2241 ; found, 316.2235. Elemental analysis (calc. for C22H26B1N1): C 83.65 (83.77), H 8.45 (8.31 ), N 4.29 (4.44).

Example 5: synthesis of (NC₄H₄)B(CeH '₅)₂ 5

A solution of B(CeH5)2CI (1.64 g, 8.19 mmol) in 20 cm³ EkO was added (via cannula) to a suspension of lithium pyrrol-1-ide (0.60 g, 8.19 mmol) in 20 cm³ Et20, and stirred at +20 °C for 18 hours. The reaction mixture was filtered (via cannula) to isolate a golden yellow solution, from which volatiles were removed in vacuo, and the solid washed with small portions cold petroleum ether, to give the product as a pale orange solid. Yield 0.57 g (2.46 mmol, 30%). 5 may be further purified via sublimation at +90 °C / 10^~1 mbar.

¹H NMR (500.2 MHz, CDC , 25 °C, δ): +7.56 (d, ³JHH = 7.4 Hz, 4H, Ph o-H), +7.45 (t, ³JHH = 7.4 Hz, 2H, Ph p-H), +7.36 (dd, ³JHH = 7.4, 7.4, 4H, Ph m-H), +7.08 (m, 2H, pyrrolyl 2,5-H), +6.42 (m, 2H, pyrrolyl 3,4-H); ¹B NMR (160.5 MHz, CDCI3, 25 °C, δ): +49.4 (br.s); ³C{ H} NMR (125.8 MHz, CDCI3, 25 °C, δ): +136.7 (s, Ph o-C), +135.8 (s, Ph p-C), +127.9 (s, pyrrolyl 2,5-C), +127.5 (s, Ph m-C), +1 14.0 (s, pyrrolyl 3,4-C). HRMS-ASAP (m/z): [M+H]⁺ calc. for

232.1301 ; found, 232.1295. Elemental analysis (calc. for Ci₆Hi₄BiNi): C 83.32 (83.09), H 5.89 (6.10), N 5.94 (6.05).

Example 6: synthesis of (NC₄H₄)B(C₈H '₁₄) 6

A slurry of 9-borabicyclo[3.3.1]nonane (0.65 g, 2.67 mmol) in pyrrole (0.4 cm³, 5.76 mmol) was stirred at +100 °C for 3½ hours. Volatiles were removed in vacuo to give the product as a pale yellow oil. Yield 0.76 g (4.06 mmol, 76%). ¹H NMR (500.2 MHz, CDCI₃, 25 °C, δ): +7.24 (m, 2H, pyrrolyl 2,5-H), +6.45 (m, 2H, pyrrolyl 3,4- H), +2.1 - +1.8 (m, 12H); ¹B NMR (160.5 MHz, CDCI₃, 25 °C, δ): +60.4 (br.s); ¹³C{¹H} NMR (125.8 MHz, CDCI₃, 25 °C, δ): +123.9 (s, pyrrolyl 2,5-C), +1 14.0 (s, pyrrolyl 3,4-C), +33.7 (s), +25.5 (br.s), +23.2 (s). HRMS-ASAP/APCI (m/z): [M+H]⁺ calc. for C12H19B1N1 , 188.1605; found, 188.1605. Elemental analysis (calc. for Ci₂H₁₈BiNi): C 77.28 (76.96), H 9.33 (9.69), N 7.42 (7.48).

Voltammetric characterisation of monomers 1-6

pyrrolyl borane

polymerisation reduction

(NC₄H₄)B(Ar^F5)₂ 1 +1 .21 -1 .99

(Ν0 Η )Β(ΑΓ°^Ι5)₂ 2 +1 .1 1 -2.07

(NC H₄)B(Ar^F6)₂ 3 +1 .12 -2.31

(NC₄H₄)B(Mes)₂ 4 + 1 .43 < -2.5

(NC H₄)B(Ph)₂ 5 +1 .1 8 < -2.5

(NC H₄)B(C₈Hi₄) 6 + 1 .48 < -2.5

Pyrrole +1 .09 -

Table 1 : Oxidative and reductive peak potentials (E_p) recorded for 1-6 at a GC electrode (scan rate l OOmVs ; CH₂CI₂, 0.05M [ⁿBu₄N][B(C₆F₅)4]) .

Voltammetric characterisation of monomers 1-6 was performed at a glassy carbon electrode in anhydrous dichloromethane with 0.05M ["Bu₄N][B(CeF5)4] at 100 mVs ^~ The results are shown in Figure 1 a-f [a) 2.5 mM 1 ; b) 1.5 mM 2; c) 2.5 mM 3; d) 2.5 mM 4; e) 1 .5 mM 5; f) 5.0 mM 6].

In all cases, a distinct oxidation wave was observed in the range +1 .1 to +1 .5 V vs [FeCp₂]^0/+ corresponding to the electropolymerisation of the pyrrolyl moiety (Table 1 , Figure 1a-f). By comparison to the oxidation of pyrrole itself under identical conditions (+1 .09 V vs [FeCp₂]^0/+), the polymerisation peak potentials of 1-6 are all shifted to more positive potentials.

Within the limits of the solvent window (ca. -2.5 V vs [FeCp2]^0/+) a one-electron reduction wave was observed for 1-3 {i.e. the pyrrolylboranes bearing the most electron withdrawing aryl rings) between ca. -2.0 and -2.5 V.

Both the oxidative and reductive waves remain irreversible over the range of scan rates studied up to 2.0 Vs^-1. It is clear from the voltammetry that the presence of a Lewis acidic moiety alters the electronic properties of the pyrrole ring, potentially enabling the development of "tuneable" conducting polymers with differing conducting windows. The "tuning" of the polymer electronic structure may also significantly influence the charge storage capacity of the resulting polymer, as discussed below.

NMR analysis

δ_Β /

ppm pyrrolyl pyrrolyl

2,5-H 3,4-H

(NC₄H )B(Ar^F5)₂ 1 +41 .8 +6.93 +6.54

(NC₄H₄)B(Ar^cl5)₂ 2 +42.5 +6.77 +6.46

(NC₄H₄)B(Ar^F6)₂ 3 +46.5 +6.98 +6.62

(NC₄H₄)B(Mes)₂ 4 +52.1 +6.76 +6.32

(NC₄H₄)B(Ph)₂ 5 +49.4 +7.08 +6.42

(NC₄H₄)B(C₈H₁₄) 6 +60.4 +7.24 +6.45

Pyrrole — +6.93 +6.46

Table 2: NMR spectroscopic data recorded in CDC for 1-6.

Characterisation of the species 1-6 by NMR spectroscopy (Table 2) reveals that the borane and pyrrolyl resonances are strongly dependent on both the electron withdrawing and steric properties of the substituents at the borane. The ¹B chemical shift of the borane resonances correlates with the increased electron withdrawing effect of the borane substituents {5B: 1 (CeF₅) ^α 2 (C6CI₅) < 3 ((CF₃)₂C₆H₃) < 5 (phenyl) < 4 (mesityl) < 6 (C₈Hi )}, whilst the ¹H chemical shifts of the pyrrolyl 2,5- H resonances correlate with the steric bulk of the borane substituents 5». 4 (mesityl) « 2 (C6CI5) < 1 (C6F5) < 3 ((CF₃)₂C₆H₃) < 5 (phenyl) < 6 (C_eHi₄)}. X-ray analysis

B-N I k N-C2 / A C2=C3 / A pyrrolyl aryl

'twist' 'twist' angle angle

(NC₄H₄)B(Ar^F5)₂ 1 1 .401 (5) 1 .402(3) 1.346(4) 2.2° 58.9°

(NC₄H₄)B(Ar^cl5)₂ 2 1 .442(6) 1 .403(6) 1.334(6) 5.7° 60.9°

1 .416(6) 1.336(6)

(NC₄H₄)B(Mes)₂ 4 1 .443(2) 1.395(2) 1.355(3) 15.8° 59.4°

1 .400(2) 1.355(3)

Pyrrole - 1.365 1 .357 -

Cyclotriborazane 1.574

B-N single bond

Borazine 1.430

B-N aromatic bond

Table 3: X-ray crystallographic structural parameters for 1 , 2, and 4

B(C₆CI₅)2(NC4H₄) 2 B{o,o,p-(CH₃)3C6H2}2(NC₄H4) 4 empirical formula Ci6 H₄ Bi Clio Ni C22 H26 Bi Ni

formula weight 575.51 315.25

temperature / K 140(1) 100(1)

crystal system monoclinic monoclinic

space group C2/c P2i/n

a/A 29.7229(13) 11.9250(5)

blk 8.4880(4) 8.0239(3)

elk 16.6048(9) 19.6593(9)

a/° 90.0 90.0

β/° 100.550(5) 100.068(4)

γ/° 90.0 90.0

volume / A³ 4118.4(4) 1852.1(2)

Z 8 4

Pcaic / mg.mrrr³ 1.856 1.131

μ / mm^-1 1.358 0.064

F(000) 2256 680

crystal size / mm³ 0.1 x 0.1 x 0.05 0.2 x 0.2 x 0.03

Radiation Mo Κα(λ = 0.71073 A) o Κα(λ = 0.71075 A)

2Θ range for data collection 5.70 to 52.74° 5.50 to 54.96°

index ranges -36 < h≤ 36, -10 < k≤ 10, -15 < A? < 15, -10 < Ar< 10, -24

-20</< 14 </<25

reflections collected 17429 21957

independent reflections 4211 [Rim = 0.0862, R_sigma 4256 [Rint = 0.0407, Rsigma =

= 0.990] 0.0326]

data / restraints / parameters 4211 /0/253 4256 / 0 / 255

goodness-of-fit on F² 0.995 1.202

final R indexes [Ι≥2σ(Ι)] Ri = 0.0554, wR₂ = 0.0990 Ri = 0.0684, wR₂ = 0.1422 final R indexes [all data] Ri = 0.1255, wR₂ = 0.1183 Ri = 0.0764, wR₂ = 0.1467 largest diff. peak / hole / e.A^"3 0.46 / -0.39 0.31 / -0.21

Table 4: Crystallographic Data for 2 and 4

Single crystal X-ray structures of compounds 2 and 4 were obtained (3 and 5 are amorphous, 6 is an oil) as shown in Figures 2a-c [a) X-ray crystallographic structure of B(Ar^cl5)2(NC₄H4) 2; b) X- ray crystallographic structure of B(mesityl)2(NC4H₄) 4; c) Resonance structures showing the double bond character of the B-N bonding in monomers 1-6] and Tables 3 and 4. The structures comprise a trigonal planar boron centre with the two aryl rings twisted with respect to the trigonal plane. The pyrrole ring remains approximately co-planar with the trigonal plane.

Structural features of note include the unusually short B-N single-bond lengths in comparison to, for example, the B-N single bonds in the cyclohexane analogue cyclotriborazane (see Table 3). Indeed, the bond lengths in 1-5 are comparable to those of the aromatic B-N bonds of the benzene analogue borazine. Alongside a contraction of the B-N bond length, an alternation in the C-C bond lengths around the pyrrole ring was observed. This is indicative of a significantly greater localisation of the double-bond character of the pyrrolyl C2=C3 bonds, and single-bond character of the N-C2 bonds, than is observed in the de-localised aromatic system of pyrrole itself.

Together these structural features imply a significant bonding interaction between the vacant p_z orbital of boron and the lone pair p_z orbital on nitrogen; with the minimal twist of the pyrrolyl ring to ensure appropriate symmetry for ττ-bonding. This in turn leads to a reduction in the aromatic character of the pyrrolyl ring (Figure 2c). The additional B-N bonding interaction, and subsequent modulation of the N-pyrrolylborane electronic structure have implications for both the Lewis acidity/electrophilicity of the boron centre, and the electropolymerisation of the pyrrolyl moiety.

The additional B-N π-bonding interactions are also apparent in DFT calculations performed on 2 and 5 (Figure 3, and Tables 5 and 6 below). Figure 3 shows a) highest occupied NBO-8 of 5, showing B-N π orbital; b) lowest unoccupied NBO+8 of 5, showing B-N ττ* orbital; c) highest occupied NBO-4 of 2, showing B-N π orbital; d) lowest unoccupied NBO+8 of 2, showing B-N ττ* orbital.

Natural bond order calculations clearly identified the presence of some ττ-orbital interaction between boron and nitrogen, whilst alternation in bond lengths suggestive of some de- aromatisation of the pyrrolyl ring were also clearly observed.

B-N/A N-C2/ C2=C3 C3-C3' pyrrolyl aryl

A Ik Ik 'twist' 'twist'

angle angle

C-B- N-B-

N-C C-C

(NC₄H₄)B(Ar^F5)₂1 1.419 1.408 1.357 1.442 8.7° 60.4°

(NC₄H₄)B(Ar^cl5)₂2 1.425 1.405 1.358 1.441 15.6° 60.7°

(NC₄H )B(Ar^F6)₂3 1.437 1.406 1.361 1.437 18.1° 42.3°

(NC₄H₄)B(Mes)24 1.451 1.399 1.364 1.437 17.3° 58.9°

(NC₄H₄)B(Ph)₂4 1.451 1.400 1.364 1.435 20.0° 40.6°

(NC₄H₄)B(C₆Hi₄) 6 1.442 1.399 1.364 1.436 2.5° -

N-pyrrole - 1.375 1.377 1.425 - -

Table 5: Selected bond lengths & dihedral ('twist') angles for 1-6 calculated using B3LYP/6- 311 +G(d,p) computations.

B-N N-C2 C2=C3 C3-C3'

B(Ph)₂(NC H₄) 1 0.8766 1.0964 1.6405 1.2465

1.0964 1.6405

B(Ar^F5)₂(NC₄H₄) 2 0.9744 1.0582 1.6819 1.2118

1.0582 1.6819

B(Ar^cl5)₂(NC₄H ) 3 0.8793 1.0560 1.6747 1.2154

1.0590 1.6759

B(Mes)₂(NC₄H₄) 4 0.8238 1.0878 1.6471 1.2393

1.0876 1.6478

B(Ar^F6)₂(NC₄H₄) 5 0.9229 1.0774 1.6572 1.2334

1.0774 1.6572

C₈Hi₂B(NC₄H₄) 6 0.8359 1.0894 1.6476 1.2451

1.0894 1.6476

A/-pyrrole - 1.1840 1.5660 1.3277

Table 6: B3LYP/6-311 +G(d,p) NBO Wiberg bond indices calculated for monomers 1-6. Electropoiymensation

Cyclic voltammetric electropoiymensation of pyrrole, 1, and 2 were separately performed at GC, GP, CC, and CF electrodes immersed in anhydrous DCM electrolyte solutions containing 10 mM of the monomer of interest and 0.1 [ⁿBu4N][B(CeF₅)4] as supporting electrolyte. All potentials quoted in the procedure below were internally referenced to the peak potential of the main monomer oxidation peak.

Before performing any voltammetric electropolymerisation at a given graphitic electrode of interest, a separate GC working electrode was first used to scan from -0.4 to 1.5 V vs Ag to ascertain the polymerization peak potential value. The cyclic voltammetric electropolymerisation on the working electrode of interest then commenced by oxidatively sweeping the potential from a value 1000 mV negative of the monomer oxidation peak potential to a value 500 mV more positive at an optimised scan rate of 100 mV.s^"1. The scan direction was then reversed, sweeping to a value 1300 mV negative of the monomer oxidation peak before reversing once again back to the starting potential to complete one cycle. Commonly this saw a start potential of -0.1 V vs. Ag with sequential turning points at ca. 1.4 V and -0.4 V vs. Ag. The electropolymerisation cycle was then repeated for between 20-160 cycles to deposit varying thicknesses of the polymer films on the electrode surfaces.

Having established the relative redox characteristics for the non-aqueous electrochemistry of pyrrole, and the pyrrolylborane monomers 1-6, we next investigated the

electropolymerisation of 1-3 on a GC electrode. Both chronoamperometric and cyclic voltammetric methods can be used to form conducting polymer-modified electrodes. The films of poly(1 )-poly(3) formed by voltammetric cycling past the oxidative polymerisation peak were found to be highly conductive and can be reproducibly grown on a variety of different graphitic carbon electrodes (GC, GP, CC, and CF electrodes).

Returning to our initial characterisation on a GC electrode surface, we observed that as the films of poly(1 ) - poly(3) grow on the electrode surface, new oxidative and reductive features at lower potentials than the polymerisation peak potential gradually appeared. These correspond to the onset of the conducting region and associated capacitive charging behaviour of the polymers films on the electrode surface (Figure 4a-d). Figure 4 shows overlaid cyclic voltammograms recorded at a GC electrode in DCM containing 0.1 M

[ⁿBu₄N][B(C_sF₅)4] at 100 mVs for: a) 40 cycles of 10 mM 1 ; 20 cycles of 10 mM 2; 20 cycles of 10 mM 3; d) A comparison of the capacitive charging behaviour of poly(pyrrole) and poly(1) modified GC electrodes (20 cycles) recorded in DCM containing 0.1 M [ⁿBu₄N][B(C₆F₅)4] at 100 mVs^"1 in the absence of any monomer in solution.

In the case of poly(pyrrole) the onset of the conducting capacitive charging region occurs at ca. -640 mV vs Cp2Fe^{0 +}, whilst in the case of poly(1 ), poly(2), and poly(3) this is shifted anodically to -200 mV, -225 mV, and -180 mV vs Cp2Fe^0/+ respectively indicating that the electronic properties and charge-storing voltage range of the resulting LAM P conducting polymer materials can be "tuned" according to the nature of the pendant Lewis acid groups.

To investigate the charge storage properties of the Lewis acid modified polymers further, a series of GC electrodes bearing either poly(pyrrole), or poly(1 ) that had undergone increasing numbers of polymerisation cycles were prepared. These were immersed into an electrolyte solution containing none of the corresponding monomer species, and the cyclic voltammetric responses recorded. As can be seen in Figure 4d, the redox features associated with the capacitive charging and discharging regions can still be clearly observed except now the oxidative polymerisation peak is absent, as expected. Variable voltage scan rate experiments (10-1000 mVs^" ) were performed on each of the three polymer materials formed after 20 cycles, and a linear response in charging peak current with increasing scan rate was observed, confirming that the polymers were each bound to the electrode surface.

The mass of poly(pyrrole) and poly(1 ) deposited during the electropolymerisation process was recorded for comparison at a 6MHz AT-cut carbon-coated quartz electrode using an electrochemical quartz crystal microbalance (EQCM) over 60 polymerisation cycles. The change in resonant frequency, Af of the oscillating quartz crystal was then related to the polymer mass deposited using the Sauerbrey equation [Equation (1 )]:

Af

where Af is the change in frequency (Hz), CV is the sensitivity factor of the crystal (0.0815 Hz ng^"1 cm^-2 for a 6 M Hz crystal at 20 °C), Am is the mass change per unit area (ng cm^-2), A is the electrode are (cm²), f is the resonant frequency of the fundamental mode of the loaded crystal, n is the number of harmonics at which the crystal is driven (set to 1 by design), p_q is the density of quartz (2.648 g cm^-3), and μ_η is the shear modulus of quartz (2.947 x10^{1 1} g cm^"1 s^"2).

Figure 5a shows the resulting EQCM massogram data for poly(1 ) [overlaid current-voltage (solid lines) and corresponding mass-voltage (dashed lines) recorded for the 1 ^st, 20^th and 60^th electropolymerisation cycle of 1 using EQCM measurements at a carbon-coated quartz electrode] whilst Figure 5b shows the mass added per cycle over the first 10 cycles for both poly(pyrrole) and poly(1 ) for comparison [the corresponding plots of mass being added during the first 10 polymerisation cycles of poly(pyrrole) and poly(1 ) determined by EQCM

measurements]. It is clear from the EQCM studies that, despite the pyrrole monomer weighing considerably less than 1 (66.08 g mol^"1 vs. 41 1.01 g mol^" respectively), more poly(pyrrole) is deposited per cycle onto the electrode than poly(1 ). This is consistent with the increased steric bulk of the N-pyrrolyl > s(aryl)borane leading to slower, more hindered, and therefore more ordered polymer chain growth than in the case of poly(pyrrole) which is evident from the morphological and capacitive studies of the LAMP cf. poly(pyrrole) discussed below.

The morphology of the poly(1 ) films formed on the surface of a GC electrode was examined using SEM imaging. Specially designed GC electrodes were modified with films (formed using up to 200 polymerisation cycles) of poly(1 ). These were then sealed in epoxy resin, cross-sectioned to reveal the electrode-polymer-epoxy interface, and then imaged. Figure 6 shows a) SEM image and b) the corresponding EDX analysis through a 15.6 μιη thick (200 cycle) layer of poly(1 ) grown on a GC electrode showing the relative atomic % of C, O, and F.

As can be seen in Figure 6a, the poly(1 ) film is clearly evident, and the film thickness was found to increase with increasing polymerisation cycles, extending to several tens of microns. The poly(1 ) layer appears to grow in a dense layer extending normal to the electrode surface. EDX analyses (Figure 6b) comparing the relative atomic percentage of carbon, oxygen and fluorine at several points traversing the electrode-polymer-epoxy interface confirms the presence of either the B(CeF₅)2 groups within the polymer and/or the incorporation of [B(C6F5)₄]^~ electrolyte ions exclusively within the polymer film region.

Capacitor assembly

The capacitor devices were separately assembled using either high surface area CC electrodes (1.0 x 2.0 mm geometric area) onto which either pyrrole or 1 were electropolymerised via 80 repeat voltammetric cycles to form a series of poly(pyrrole) or poly(1) modified carbon electrodes. The capacitor devices were assembled in a two-electrode configuration immersed in DCM containing 0.1 M [ⁿBu4N][B(C6F₅) ] electrolyte using a symmetric arrangement of two poly(1 )- modified electrodes.

Characterisation of capacitive properties of LAMP films

The charge stored in the capacitive region of poly(1 ) and poly(pyrrole) was recorded during the voltammetric electropolymerisation process and is shown for comparison in Figure 7 [comparison of the charge storage capacity for poly(pyrrole) vs. poly(1 ) LAMP as the polymers grow with increasing polymerisation cycle number]. It is clear that poly(1 ) is capable of storing a greater charge density than the conventional poly(pyrrole) material despite there being a lower mass of the LAMP material deposited on the electrode.

To examine the charge storage properties of poly(1 ) LAMP films further, the specific capacitance, C_s (Fg^_1), of films of poly(1 ) deposited via 20 electropolymehsation cycles onto several different GC electrodes was then examined in both dichloromethane (DCM) and acetonitrile (MeCN) solutions containing three different electrolyte salts: ["Bu4N][B(C6F₅)4], ["Bu4N][PFe], or ["Bu4N][BF4]. Cyclic voltammograms were recorded for several poly(1 )- modified electrodes in each electrolyte solution at varying scan rates (2-100 mVs^"1). The oxidative and reductive charging currents were recorded and these values, together with the mass of the films ascertained from the EQCM measurements in section 3.3 were used to evaluate the specific capacitance according to Equation (2):

CW ₍₂₎ where / are the oxidative and reductive charging currents (A), m is the mass of the polymer film (g), and v is the voltage scan rate (Vs^-1). The resulting specific capacitance values are listed in Table 7 below.

DCM

[ⁿBu₄N][B(C₆F5)4] [ⁿBu₄N][PF6] [ⁿBu₄N][BF₄]

Specific 324 ± 35 486 ± 20 690 +50

capacitance

(Fg-¹) MeCN

[ⁿBu₄N][B(C₆F₅)4] [ⁿBu₄N][PF₆] ["Bu₄N][BF₄]

432 ± 35 517 ± 60 644 ± 50

Table 7: Average specific capacitance values obtained by cyclic voltammetric measurements of films of poly(1 ) deposited on GC electrodes (20 polymerisation cycles) and recorded at 2, 5, 7.5, 10 and 100 mVs^"1 voltage scan rate in electrolytes containing 0.1 M of the salts listed.

It is immediately apparent that, in agreement with Figure 7, the LAMP material has a much greater specific capacitance (charge storing capability) than the conventional conducting polymer, poly(pyrrole) formed under identical conditions and which typically exhibited a specific capacitance in the range 40-100 F/g. Another technique to measure the charge storage properties (specific capacitance, stable operating voltage range, and the effects of repeated charge-discharge cycling) of conducting polymer films is to subject them to galvanostatic charging-discharging cycles. The poly(1 )-modified GC electrodes were subjected to a charging current ramp of 1 Ag^~1 for 30 s between 0 and 1 .0 V, and then discharged back to 0 V over a further 30s period. This was repeated for 6000 charge-discharge cycles.

I n order to assess the potential of LAMP films to serve as supercapacitive devices, two CC electrodes (of area 0.02 cm²) were modified with poly(1 ), and then assembled into a symmetric capacitor device by immersing both electrodes into a solution of DCM containing 0.1 M [ⁿBu₄N][B(C6F₅)4] .

To establish the stable operational voltage range of the LAMP materials, these were subjected once again to galvanostatic charge discharge cycles at a constant current demand of 20Ag^~1 , but with no voltage limits. Figure 8 shows a) the first ten and last ten cycles of a series of 6000 galvanostatic charge-discharge cycles recorded for a poly(1 ) modified GC electrode immersed in DCM containing 0.1 M [ⁿBu4N][B(C6Fs)4] at 1 Ag^_1 over a 0-1 V range; and b) Repeated galvanostatic charge-discharge cycles recorded for a symmetric poly(1 ):poly(1 )- modified CC supercapacitor in DCM containing 0.1 M [ⁿBu₄N][B(C6F₅)4] at 20 Ag^_1. Figure 9 shows images of the symmetric poly(1 ):poly(1 )-modified CC supercapacitor assembly in b) during charging (top) and discharging (bottom) to illuminate a green LED connected (indicated with an arrow) across the capacitor device terminals.

As can be seen from Figure 8a the resulting charge-discharge curves are remarkably stable over 6000 repetitive cycles, with no obvious signs of voltage instability of the poly(1 ) material or other degradation in performance. The average specific capacitance recorded for several electrodes under these conditions was estimated from the slope of the galvanostatic discharge curve according to Equation (3):

where / is the current demand (A), m is the mass of the polymer film (g), and dV/dt is the gradient of the potential discharge curve. For poly(1 ) in DCM containing 0.1 M

["Bu4N][B(C6F5)₄] we obtained an average specific capacitance, Cf of 366 ±30 Fg^"\ in excellent agreement with the values obtained from the voltammetric capacitance

measurements above. After subjecting the LAMP film to 6000 charge-discharge cycles, the specific capacitance of the poly(1 ) films had decreased to 31 0 ± 10 Fg^_ . It should be noted that the majority of this 16% decrease occurred during the first 100 cycles, after which the specific capacitance remained almost constant for the remaining 5900 cycles.

As can be seen from Figure 8b, the symmetric supercapacitor arrangement of poly(1)- modified electrodes gave a stable and reproducible charging and discharging response over a stable operating voltage window of ± 4.0 V. To demonstrate that this was a genuine voltage performance, the symmetric poly(1 ):poly(1) supercapacitor was charged as before, except that this time it was discharged through a green LED which requires a minimum voltage of 3.2 V to power it on. As can be seen in Figure 9, the symmetric poly(1):poly(1 ) capacitor was able to light this LED during discharge.

Claims

1. A polymer comprising a conductive backbone having a plurality of Lewis pair side chain moieties thereon, said Lewis pair side chain moieties each comprising: a Lewis acid moiety (LA) comprising an electron pair acceptor, and a Lewis base moiety (LB) comprising an electron pair donor, wherein the Lewis acid moieties of said Lewis pair side chain moieties are each electrically connected to the conductive backbone.

2. The polymer according to claim 1 , wherein said electron pair acceptor comprises a Group 13 element, such as boron or aluminium.

3. The polymer according to any claim 2, wherein said Group 13 element is boron.

4. The polymer according to any preceding claim, wherein the electron pair acceptor is

bonded to one or more (e.g. two) R^A moieties, the or each R^A being independently selected from optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, carbocyclic and heterocyclic; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring; and/or wherein the electron pair acceptor is bonded to two or more moieties which, taken together with the electron pair acceptor to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6- membered aromatic or 4- to 8-membered non-aromatic ring.

5. The polymer according to any preceding claim, wherein the electron pair acceptor is

bonded to two R^A moieties, optionally wherein said R^A moieties are the same.

6. The polymer according to claim 4 or 5, wherein the one or more R^A moieties are substituted by one or more of moieties independently selected from an optionally substituted aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, halogen, -NO2, -CN, -C(R)=C(R)2, -C≡C-R , -OR , -SR', -S(0)R", -S0₂R', -SO3R , -S0₂N(R )₂, -N(R)₂, -[N(R)₃]⁺, -NRC(0)R , -NRC(0)N(R)₂, -NR CO2R, -NRSO2R', -NRS0₂N(R)2, -0-C(0)R , -0-C0₂R, -OC(0)N(R), -C(0)R, -CO2R, -C(0)N(R)₂, -Si(R)₃, -P(R)₂, -[P(R^')₃]⁺, -P(0)(R)₂, -P(0)(OR)₂,

-0-P(0)-OR, wherein R, independently, is hydrogen, halogen or aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, or two occurrences of R are taken together with their intervening atom(s) to form a 5-7-membered aromatic, heteroaromatic, cycloaliphatic, or heterocyclic ring, optionally wherein each R is, independently, substituted.

7. The polymer according to any one of claims 4 to 6, wherein the or each R^A is independently selected from:

wherein each R^{1 a} is independently selected from an optionally substituted aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, halogen, -NO2, -CN, -C(R )=C(R )₂, -OC-R , -OR , -SR', -S(0)R', -SO2R', -SO3R^', -S0₂N(R)₂, -N(R)₂, -[N(R)₃]⁺, -NRC(0)R , -NR C(0)N(R)₂, -NRCO2R , -NR^'S0₂R\ -NRS0₂N(R )₂, -0-C(0)R , -O-CO2R , -OC(0)N(R ), -C(0)R^', -CO2R^', -C(0)N(R^')₂, -Si(R )₃, -P(R)₂, -[P(R^')₃]⁺, -P(0)(R^")₂, -P(0)(OR^')₂,

-0-P(0)-OR, wherein R , independently, is hydrogen, halogen or aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, or two occurrences of R^' are taken together with their intervening atom(s) to form a 5-7-membered aromatic, heteroaromatic, cycloaliphatic, or heterocyclic ring, optionally wherein each R is, independently, substituted; wherein n is selected from 0, 1 , 2, 3, 4 or 5; and optionally wherein each R^' is, independently, substituted.

8. The polymer according to claim 7, wherein n is 1 , 2, 3 or 5, optionally wherein n is 5.

9. The polymer according to any one of claims 4 to 8, wherein the or each R^A is independently selected from:

wherein the or each R , independently, is as defined in claim 7.

10. The polymer according to any one of claims 7 to 9, wherein the or each R ^a is an electron withdrawing group.

1 1 . The polymer according to any one of claims 7 to 10, wherein the or each R^{1 a} is

independently selected from halogen, -C(0)R^', -C0₂R , -C(0)N(R^')₂, halogen substituted aliphatic, -CN, -SO3R^', -[N(R^')₃]⁺, or -N0₂.

12. The polymer according to any one of claims 7 to 1 1 , wherein the or each R ^a is a halogen, such as F, CI, Br; optionally wherein the or each R^1a is F or CI, optionally wherein the or each R^1a is F.

13. The polymer according to any one of claims 7 to 12, wherein the or each R^A is

independently selected from halophenyl, such as pentahalophenyl (e.g. pentafluorophenyl or pentachlorophenyl); 3,5 bis(trifluoromethyl)phenyl; 1 ,3,5 trimethyl phenyl; or wherein two said R^A moieties form a bridged carbocycle bridged by the electron pair acceptor to which they are attached, optionally wherein the bridged carbocycle is a bridged cyclooctane.

14. The polymer according to claim 13, wherein the or each R^A is pentafluorophenyl.

15. The polymer according to any one of claims 7 to 1 1 , wherein the or each R^1a is halogen substituted aliphatic; optionally wherein the or each R ^a is trihalomethyl; optionally wherein the or each R^1a is trifluoromethyl or trichloromethyl; optionally wherein the or each R^1a is trifluoromethyl.

16. The polymer according to any preceding claim, wherein the electron pair donor is a Group 15 element, such as nitrogen or phosphorus.

17. The polymer according to claim 16, wherein the Group 15 element is nitrogen.

18. The polymer according to any preceding claim, wherein said backbone comprises a

conjugated system.

19. The polymer according to any preceding claim, having the formula (I):

wherein each R^B is independently selected from hydrogen, optionally substituted alkyl, alkenyl, aryl, heteroaryl, carbocyclic and heterocyclic, and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted fused 4- to 8-membered non-aromatic ring having 0-3 ring heteroatoms selected from the group consisting of N, O and S; and/or wherein two R^B moieties, taken together with the intervening atoms to which they are bonded, form an optionally substituted bicyclic ring moiety, each ring in the bicyclic ring independently being a 5- to 6-membered aromatic or 4- to 8-membered non-aromatic ring; wherein X^LB is the electron pair donor as defined in any preceding claim; wherein LA is the Lewis acid moiety as defined in any preceding claim; and wherein m is an integer of at least about 3; optionally greater than about 10.

20. The polymer according to claim 19, wherein the one or more R^B moieties are substituted by one or more of moieties independently selected from an optionally substituted aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, halogen, -NO2, -CN, -C(R")=C(R")2, -C≡C-R^", -OR", -SR", -S(0)R'\ -SO2R", -S0₃R", -S0₂N(R")₂, -N(R")₂, -[N(R")₃]⁺,

-NR"C(0)R", -NR"C(0)N(R")₂, -NR"C0₂R", -NR"S0₂R", -NR"S0₂N(R")₂, -0-C(0)R", -0-C0₂R", -OC(0)N(R"), -C(0)R", -C0₂R", -C(0)N(R")₂, -Si(R")₃, -P(R")₂, -[P(R")3]⁺, -P(0)(R")₂, -P(0)(OR")₂, -0-P(0)-OR", wherein R", independently, is hydrogen, halogen or aliphatic, heteroaliphatic, aromatic or heteroaromatic moiety, or two occurrences of R" are taken together with their intervening atom(s) to form a 5-7-membered aromatic, heteroaromatic, cycloaliphatic, or heterocyclic ring, optionally wherein each R" is, independently, substituted.

21. The polymer according to claim 19, wherein the one or more R^B moieties are hydrogen, optionally wherein both R^B moieties are hydrogen.

22. The polymer according to any preceding claim, wherein said backbone comprises pyrrole and/or thiophene moieties.

23. The polymer according to any preceding claim, wherein said backbone comprises pyrrole moieties.

24. A compound having the formula (II):

wherein X^LA is the electron pair acceptor according to any preceding claim; wherein X^LB is the electron pair donor according to any preceding claim; wherein each R^A is, independently, as defined in any one of claims 4 to 15; wherein each R^B is, independently, as defined in any one of claims 19 to 21 ; and with the proviso that the compound is not:

25. The compound according to claim 24, with the proviso that the compound is not:

26. The compound according to claim 24 or 25, selected from:

27. The compound according to claim 24 or 25, wherein the compound is:

28. The compound according to claim 24 or 25, wherein the compound is:

29. Use of a compound having the formula (II):

wherein X^LA is the electron pair acceptor according to any one of claims 1 to 23; wherein X^LB is the electron pair donor according to any one of claims 1 to 23; wherein each R^A is, independently, as defined in any one of claims 4 to 15; wherein each R^B is, independently, as defined in any one of claims 19 to 21 ; in the formation of a conductive polymer.

30. Use of a compound according to claim 29, wherein the compound is as defined in any one of claims 24 to 28.

31. A polymer comprising a conductive backbone having a plurality of Lewis pair side chain moieties thereon, said polymer being formed from polymerisation of one or more monomers, the one or more monomers comprising one or more compounds having the formula (III):

wherein X^LA is the electron pair acceptor according to any preceding claim; wherein X^LB is the electron pair donor according to any preceding claim; wherein each R^A is, independently, as defined in any one of claims 4 to 15; and wherein each R^B is, independently, as defined in any one of claims 19 to 21.

32. The polymer according to claim 31 , wherein the one or more compounds are selected from:

33. The polymer according to claim 31 or 32, wherein the one or more compounds are selected from:

34. The polymer according to claim 31 or 32, wherein the one or more compounds are selected from:

35. The polymer according to claim 31 or 32, wherein the one or more compounds are selected from:

36. The polymer according to claim 31 or 32, wherein the one or more compounds are selected from:

37. The polymer according to claim 31 or 32, wherein the one or more compounds are selected from:

38. The polymer according to claim 31 or 32, wherein the one or more compounds are selected from:

39. The polymer according to any one of claims 31 to 38, wherein the one or more monomers further comprise pyrrole and/or thiophene, optionally pyrrole.

40. The polymer according to any one of claims 31 to 38, wherein the one or more monomers consist essentially of the compound(s).

41. The polymer according to any one of claims 31 to 40, wherein the polymer is a

homopolymer or a co-polymer; optionally wherein the polymer is a homopolymer.

42. A polymer substantially as hereinbefore described with reference to the accompanying description and/or figures.

43. An electrode comprising a polymer according to any one of claims 1 to 23 or 31 to 42

present as one or more layers on the surface of said electrode.

44. The electrode according to claim 43, wherein said electrode comprises a carbon electrode, such as glassy carbon, graphite plate, or carbon fibre cloth.

45. An electrode substantially as hereinbefore described with reference to the accompanying description and/or figures.

46. A battery or capacitor comprising one or more polymers according any one of claims 1 to 23 or 31 to 42.

47. A battery or capacitor comprising one or more electrodes according to any one of claims 43 to 45.

48. A battery or capacitor substantially as hereinbefore described with reference to the

accompanying description and/or figures.

49. A method of producing a polymer, comprising: polymerising one or more compounds as defined in claim 24 to 31 , optionally further comprising pyrrole and/or thiophene moieties, optionally pyrrole moieties.

50. The method of producing a polymer according to claim 49, wherein said polymerising is conducted by electropolymerisation.

51. The method of producing a polymer according to claim 49 or 50, wherein said polymerising is conducted under non-aqueous conditions (e.g. an organic, optionally halogenated solvent, such as dichloromethane).

52. A method of producing a polymer substantially as hereinbefore described with reference to the accompanying description and/or figures.