Triethylene Glycol Side Chains Research Articles

Exploring the reactivity and interactions of a poly(fluorene‐co‐tetrazine)‐conjugated polymer with Single‐walled Carbon Nanotubes

AbstractConjugated tetrazine‐containing polymers that undergo inverse electron demand Diels‐Alder (IEDDA) reactions with trans‐cyclooctenes are interesting not only for their intrinsic optoelectronic properties, but also their interactions with π‐conjugated surfaces. Here, we prepared a series of poly(fluorene‐co‐tetrazine) polymers and carried out IEDDA reactions to decorate them with hydroxyl, hexadecyl, or triethylene glycol side chains. The polymers were investigated pre‐ and post‐IEDDA coupling in terms of their ability to disperse single‐walled carbon nanotubes (SWNTs) in organic solvent. It was found that polymer molecular weight, side chain structure, and degree of conjugation all impacted the quality of SWNT dispersions. While the starting poly(fluorene‐co‐tetrazine) polymer produced concentrated dispersions, the post‐IEDDA polymer containing dihydropyridazine groups did not produce dispersions of equal concentration. However, upon oxidation to the fully aromatic pyridazines, the polymers regained their ability to form concentrated dispersions. Furthermore, the post‐IEDDA polymers exhibited increased selectivity toward metallic SWNTs relative to the starting polymer. Due to the efficiency of the IEDDA reaction, it was also possible to use this chemistry to derivatize the nanotube complex with poly(fluorene‐co‐tetrazine) post‐dispersion. Overall, this work demonstrates the first use of reactive polytetrazines to disperse SWNTs, allowing rapid modification of polymer‐nanotube complexes.

Self-Assembled Monolayers of Gemini-Type Amphiphilic Hexabenzocoronenes on Gold: Contribution of Their Triethylene Glycol Side Chains to Self-Assembly Formation.

We report on a two-dimensional self-assembled structure of a supramolecule with hydrophilic oligoethylene glycol (EG) units, which are capable of stronger electrostatic interactions than van der Waals (vdW) interactions between alkyl chains. For this purpose, hexabenzocoronene (HBC) with two hydrophobic dodecyl chains on one side of the HBC core and two hydrophilic triethylene glycol (TEG) chains on the other side of the HBC core (HBCGemini) and HBCGemini with a trinitrofluorenone (TNF) added to the end of one TEG chain (HBCTNFGemini) were employed. Scanning tunneling microscopy (STM) revealed the presence of multiple two-dimensional self-assembled structures in each of HBCGemini and HBCTNFGemini deposited on the gold substrate in vacuum. The role of polar functional groups in these observations is discussed based on semiempirical molecular orbital simulations. Two types of 2D organized structures of HBC-TEG were observed: one with rectangular and relatively dense unit cells and the other with nearly square and relatively sparse unit cells. In both organized structures, the phenyl group TEG units and alkyl chains were considered to be the main molecular interactions with each other. On the other hand, in HBCTNFGemini, three types of organized structures were observed, which could be explained by the mechanism of interdigitation of the TEG-containing side-chain moieties to form a dimeric core. The EG units are more flexible than the alkyl chains and thus can interact flexibly with the hydrophobic HBC core, and the glycol side chains facilitate the intermolecular interactions as well as the alkyl chains.

Ion Size-Dependent Electrochromism in Air-Stable Napthalenediimide-Based Conjugated Polymers.

Conjugated polymers (CPs) that show stable and reversible cation insertion/deinsertion under ambient conditions hold great potential for optoelectronic and energy storage devices. However, n-doped CPs are prone to parasitic reactions upon exposure to moisture or oxygen. This study reports a new family of napthalenediimide (NDI) based conjugated polymers capable of undergoing electrochemical n-type doping in ambient air. By functionalizing the NDI-NDI repeating unit with alternating triethylene glycol and octadecyl side chains, the polymer backbone shows stable electrochemical doping at ambient conditions. We systematically investigate the extent of volumetric doping involving monovalent cations of varying size (Li+, Na+, tetraethylammonium (TEA+)) with electrochemical methods, including cyclic voltammetry, differential pulse voltammetry, spectroelectrochemistry, and electrochemical impedance spectroscopy. We observed that introducing hydrophilic side chains on the polymer backbone improves the local dielectric environment of the backbones and lowers the energetic barrier for ion insertion. Surprisingly, when using Na+ electrolyte, the polymer films exhibit higher volumetric doping efficiency, faster-switching kinetics, higher optical contrast, and selective multielectrochromism when compared to Li+ or TEA+ electrolytes. Using well-tempered metadynamics, we characterize the free energetics of side chain-ion interactions to find that Li+ binds more tightly to the glycolated NDI moieties than Na+, hindering Li+ ion transport, switching kinetics, and limiting the films' doping efficiency.

A Triethyleneglycol C60 Mono‐adduct Derivative for Efficient Electron Transport in Inverted Perovskite Solar Cells†

Comprehensive SummaryInverted perovskite solar cells (PSCs) have attracted increasing attention in recent years owing to their low‐temperature fabrication proces s. However, they suffer from a limited number of electron transport materials available with [6,6]‐phenyl C61 butyric acid methyl ester (PCBM) to be the most widely studied based on its appropriate energy levels and high electron mobility. The low relative permittivity and aggregation tendency upon illumination of PCBM, however, compromises the solar cell efficiency whereas its modest hydrophobicity negatively impacts on the device stability. Alternative electron transport materials with desired properties and appropriate degree of hydrophobicity are thus desirable for further developments in inverted PSCs. Herein, we synthesize a triethyleneglycol C60 mono‐adduct derivative (termed as EPF03) and test it as a novel electron transport material to replace PCBM in inverted PSCs based on a quadruple cation (RbCsMAFA) perovskite. We also compare this derivative with two novel fullerenes decorated with two (EPF01) or one dodecyl (EPF02) long side chains. The latter two fail to perform efficiently in inverted PSCs whereas the former enabled a power conversion efficiency of 18.43%, which represents a 9% improvement compared to the reference device using PCBM (17.21%). The enhanced performance mainly stems from improved electron extraction and reduced recombination enabled by the insertion of the large relative permittivity amongst other properties of EPF03. Furthermore, our results indicate that triethylene glycol side chains can also passivate perovskite trap states, suppress ion migration and enhance photostability and long‐term stability of EPF03 based perovskite solar cells.

Synthesis and in vitro photodynamic activity of aza-BODIPY-based photosensitizers.

Aza-BODIPY dyes have recently come to attention owing to their excellent chemical and photophysical properties. In particular, their absorption and emission maxima can efficiently be shifted to the red or even to the NIR spectral region. On this basis, aza-BODIPY derivatives are widely investigated as fluorescent probes or phototherapeutic agents. Here we report the synthesis of a set of novel aza-BODIPY derivatives as potential photosensitizers for use in photodynamic therapy. Triazolyl derivatives were obtained via Cu(I)-catalyzed azide-alkyne cycloaddition as the key step. In vitro photodynamic activities of the newly synthesized compounds were evaluated on the A431 human epidermoid carcinoma cell line. Structural differences influenced the light-induced toxicity of the test compounds markedly. Compared to the initial tetraphenyl aza-BODIPY derivative, the compound bearing two hydrophilic triethylene glycol side chains showed substantial, more than 250-fold, photodynamic activity with no dark toxicity. Our newly synthesized aza-BODIPY derivative, acting in the nanomolar range, might serve as a promising candidate for the design of more active and selective photosensitizers.

Polar Side Chains Enhance Selection of Semiconducting Single-Walled Carbon Nanotubes by Polymer Wrapping

This paper describes the effectiveness of donor–acceptor (D-A) conjugated polymers to disperse and select for semiconducting single-walled carbon nanotubes (s-SWCNTs) when enhanced by the inclusion of polar oligoethylene glycol-based side chains, without altering the D–A backbone. We designed and synthesized two sets of naphthalenediimide(NDI)-alt-bithiophene(T2)-based conjugated polymers with one of two alkyl side chains (decyl and dodecyl chains) of different lengths and with or without polar triethylene glycol side chains. The resulting low-band-gap copolymers all effectively disperse and select for s-SWCNT, but the inclusion of polar side chains enhances the interactions between the polymer backbone and the walls of the s-SWCNTs relative to the polymers with only alkyl side chains. As a result, the wrapping and selection efficiency of the polymer-SWCNT systems with polar side chains are both significantly enhanced. We further optimized the binding energy and surface coverage by combining glycol ether and dodecyl side chains to maximize wrapping efficiency, leading to a field-effect mobility of 2.82 cm2 V–1 s–1 and on/off current ratios of ∼2 × 107 in polymer-wrapped SWCNTs. Our results provide insight into the role of the side-chain interactions in the polymer wrapping and dispersion technique, and, because we focus on manipulating side chains, they can be generalized for other conjugated polymer backbones.

Backbone-driven host-dopant miscibility modulates molecular doping in NDI conjugated polymers.

Molecular doping is the key to enabling organic electronic devices, however, the design strategies to maximize doping efficiency demands further clarity and comprehension. Previous reports focus on the effect of the side chains, but the role of the backbone is still not well understood. In this study, we synthesize a series of NDI-based copolymers with bithiophene, vinylene, and acetylenic moieties (P1G, P2G, and P3G, respectively), all containing branched triethylene glycol side chains. Using computational and experimental methods, we explore the impact of the conjugated backbone using three key parameters for doping in organic semiconductors: energy levels, microstructure, and miscibility. Our experimental results show that P1G undergoes the most efficient n-type doping owed primarily to its higher dipole moment, and better host–dopant miscibility with N-DMBI. In contrast, P2G and P3G possess more planar backbones than P1G, but the lack of long-range order, and poor host–dopant miscibility limit their doping efficiency. Our data suggest that backbone planarity alone is not enough to maximize the electrical conductivity (σ) of n-type doped organic semiconductors, and that backbone polarity also plays an important role in enhancing σ via host–dopant miscibility. Finally, the thermoelectric properties of doped P1G exhibit a power factor of 0.077 μW m−1 K−2, and ultra-low in-plane thermal conductivity of 0.13 W m−1K−1 at 5 mol% of N-DMBI, which is among the lowest thermal conductivity values reported for n-type doped conjugated polymers.

Thiophene- and selenophene-based conjugated polymeric mixed ionic/electronic conductors.

Mixed ionic/electronic conductors (MIECs) are desirable materials for next-generation electronic devices and energy storage applications. Polymeric MIECs are attractive from the standpointthat their structure can be controlled and anticipated to have mechanically robust properties. Here, we prepare and investigate conjugated copolymers containing thiophene and selenophene repeat units and their homopolymer counterparts. Specifically, thiophene bearing a triethylene glycol (EG3) side chain was polymerized and copolymerized with dodecyl thiophene/selenophene monomers. The synthesis leads to a class of copolymers that contain either S or Se and are blocky in nature. The Li-ion conductivity of ionically doped copolymers, P3DDT-s-P3(EG3)T and P3DDS-s-P3(EG3)T (9.7 × 10-6 and 8.2 × 10-6 S/cm, respectively), was 3-4 fold higher than that of the ionically doped constituent homopolymer, P3(EG3)T (2.2 × 10-6 S/cm), at ambient conditions. The electronic conductivity of the oxidatively doped copolymers was significantly higher than that of the constituent homopolymer P3(EG3)T, and most notably, P3DDS-s-P3(EG3)T reached ∼7 S/cm, which is the same order of magnitude as poly(3-dodecylthiophene) and poly(3-dodecylselenophene), which are the highest oxidatively doped conductors based on control experiments. Our findings provide implications for designing new MIECs based on copolymerization and the incorporation of heavy atom heterocycles.

Enhancing the Electrochemical Doping Efficiency in Diketopyrrolopyrrole‐Based Polymer for Organic Electrochemical Transistors

AbstractThe increasing interest in organic electrochemical transistors (OECTs) for next‐generation bioelectronic applications motivates the design of novel conjugated polymers with good electronic and ionic transport. Many conjugated polymers developed for organic field‐effect transistors (OFETs) exhibit high charge carrier mobilities but they are not suitable for OECTs due to poor ion‐uptake arising from the non polar alkyl chain substituted on the conjugated backbone. They are also sensitive to moisture, resulting in poor performance in aqueous electrolytes. Herein, the widely used conjugated building block diketopyrrolopyrrole (DPP) is used and functionalized it with polar triethylene glycol side chains (PTDPP‐DT) to promote ion penetration. The electrical performance of PTDPP‐DT based OECT in two types of aqueous electrolytes is studied and the electrochemical doping response is investivated. It is found that the tetrafluoroborate (BF4−) anion with large crystallographic radius allows high‐efficiency electrochemical doping of the PTDPP‐DT polymer, and thus gives rise to the high transconductance of 21.4 ± 4.8 mS with good device stability, where it maintained over 91 % of its doped‐state drain current after over 500 cycles of pulse measurement.

Semiconducting Small Molecules as Active Materials for p‐Type Accumulation Mode Organic Electrochemical Transistors

AbstractA series of semiconducting small molecules with bithiophene or bis‐3,4‐ethylenedioxythiophene cores are designed and synthesized. The molecules display stable reversible oxidation in solution and can be reversibly oxidized in the solid state with aqueous electrolyte when functionalized with polar triethylene glycol side chains. Evidence of promising ion injection properties observed with cyclic voltammetry is complemented by strong electrochromism probed by spectroelectrochemistry. Blending these molecules with high molecular weight polyethylene oxide (PEO) is found to improve both ion injection and thin film stability. The molecules and their corresponding PEO blends are investigated as active layers in organic electrochemical transistors (OECTs). For the most promising molecule:polymer blend (P4E4:PEO), p‐type accumulation mode OECTs with µA drain currents, μS peak transconductances, and a µC* figure‐of‐merit value of 0.81 F V−1 cm−1 s−1 are obtained.

Development of Helical Aromatic Amide Foldamers with a Diphenylacetylene Backbone.

We designed and synthesized aromatic polyamides with a diphenylacetylene backbone, α-DPA and β-DPA, bearing (S)-α- and (S)-β-methyl-substituted triethyleneglycol (TEG) side chains, respectively, and examined their conformations in solution. Both polymers exhibit strong, solvent polarity-dependent circular dichroism spectra, which indicated that they take helical conformations in low-polarity solvents. The spectra were mirror images, depending on the chiral position of the side chains. Thus, the polyamide α-DPA bearing (S)-α-methyl-substituted TEG groups takes a left-handed helical conformation, while the polyamide β-DPA with (S)-β-methyl-substituted TEG groups takes a right-handed helical conformation. The difference in the screw sense of α-DPA and β-DPA would be caused by the steric interaction between the main chain and the side chain, as observed in poly(p-benzamide) possessing (S)-β-methyl-substituted TEG side chains (β-PA) because the large cavity of the helical structure of DPA would disturb the solvophobically induced helical folding. Detailed conformational analyses of the oligoamides 6-12 with β-methyl-substituted TEG groups were conducted. Theoretical calculations indicated that the oligoamides with β-methyl-substituted TEG groups exist in a helical conformation with a cavity of 7 Å in diameter. The 1H NMR spectra of the oligomers revealed interactions with small anions such as chloride and acetate anions and with pyridinium cations.

Effect of Noncovalent Dispersion of Poly(Ethylene Oxide) in Columnar Polyether-Based Discotic Liquid Crystal on the Ionic Conductivity and Dynamics of Lithium Ions

The ionic conductivity of an electrolyte is represented by a product of carrier density, charge (electric), and ionic mobility. The overall goal of this study was to provide an insight into the influence of lithium ion conductivity and dynamic when a continuous discotic liquid crystal (DLC) matrix of hexaazatrinapthylene-polyether, HATN-TEG-1, is doped with a small amount of polyethylene oxide (PEO, 5% of MW 8000). The favorable non-covalent interactions between PEO and the DLC triethylene glycol side-chains is supported by the maintenance of the mesophase. The lithium ionic conductivity of HATN-TEG-1 was found to be 1.1 × 10−6 S cm−1, which is better than the corresponding HATN-TEG-1-5%PEO-8000 with a value of 6.06 × 10−7 S cm−1. These results are further supported by the dynamics of the lithium ions in HATN-TEG-1 and HATN-TEG-1-5%PEO-8000 as characterized by 7Li, and 1H NMR spin-lattice relaxation time and self-diffusion coefficient measurements. Though the additional PEO was found to increase the ion carriers, the significant lowering of the ionic conductivity may be attributed to the more pronounced decrease of the mobility of the ionic part when the HATN-TEG-1 matrix is dispersed with PEO. This finding indicates that the doping of 5% PEO onto the matrix of HATN-TEG-1 DLC has an adverse effect on both its diffusion rate and ion conductivity.

Fluorescent conjugated polymer nanoparticles and aggregates based on rapid precipitation and self-assembled π-conjugated systems

Conjugated copolymers containing fluorene and diphenylamine moieties with octyl and triethylene glycol side chains have been synthesized via Suzuki-Miyaura cross-coupling reaction and their structures have been characterized. Conjugated polymer nanoparticles and self-organization of the polymers have been prepared by rapid precipitation and solvent diffusion methods, respectively. The conjugated polymers exhibited well-defined spherical amorphous structures and crystalline microspheres with a diameter ranging from several nanometer to micrometer. Self-assembled conjugated polymer aggregates were obtained in a selective good solvent/poor solvent mixture. Alternating conjugated polymers are generally difficult to assemble into well-defined spheres due to their rigid and planar backbones, however, alternating polymers containing dioctyl and triethylene glycol side chains tends to form microspheres or sheet-like structures depending on the different solvent mixtures. The emission maximum of the dispersed polymers in water was significantly red-shifted with a dramatic reduction in the photoluminescence quantum yield. In addition, the emission maximum of the self-assembled copolymers was barely red shifted with a small reduction in the photoluminescence quantum yield.

Conjugated ionic (co)polythiophene-based cathode interlayers for bulk heterojunction organic solar cells

The incorporation of conjugated polyelectrolytes as cathode interlayers in organic photovoltaics has been proven to be an effective way to boost the device efficiency. Nevertheless, more detailed investigations of the structure–property relationships of these interlayer materials, in particular related to the film deposition behavior, can provide further insights into their mode of action. With this aim, a series of ionic (co)polythiophenes is successfully synthesized via Kumada catalyst-transfer condensation polymerization and subsequent introduction of ionic moieties on the polymer side chains. Both the topology (i.e. homopolymers, random and block copolymers) and the amount of ionic groups are systematically varied. The polymers are fully characterized and then applied as cathode interlayers in polymer solar cells based on PCDTBT:PC71BM, affording an average efficiency increase of ∼15%. The structural screening on one hand indicates that the efficiency gain is a rather general phenomenon for this material class. On the other hand, the best photovoltaic responses are observed for the conjugated polyelectrolytes with a higher triethylene glycol side chain ratio and the block copolymer structure performs slightly better as compared to the random copolymer with the same (50/50) monomer ratio. Based on these findings, the field can move on to a more rational development of novel interfacial materials and thereby push the device efficiency even further.

Cyclopentadithiophene–Terephthalic Acid Copolymers: Synthesis via Direct Arylation and Saponification and Applications in Si-Based Lithium-Ion Batteries

This study investigates conjugated polymers comprising of cyclopentadithiophene and dimethyl terephthalate or terephthalic acid units for use in Si-based lithium-ion batteries. Cyclopentadithiophene tethered with 2-ethylhexyl or triethylene glycol side chains and 2,5-dibromoterephthalate are copolymerized via palladium-complex-catalyzed direct arylation. The dimethyl ester groups in the dimethyl terephthalate unit are converted to the carboxyl groups via saponification. The polymers are mixed with Si nanoparticles to fabricate an anode electrode for use in lithium-ion batteries. Compared with polymers before saponification, the batteries with the electrodes incorporating the saponified polymers have greater specific capacities of up to 2500 mA h g–1 (for total anode weight) at a second cycle and greater stability. Electrolyte uptake test and scanning electron microscopy are used to verify the battery performance.

Complementary Semiconducting Polymer Blends: Influence of Side Chains of Matrix Polymers

The concept of complementary semiconducting polymer blends (c-SPBs) has been recently proposed to achieve enhanced solution processability and/or melt-processing capability for organic electronics. In the previous study, we demonstrated the impact of conjugation-break spacers of matrix polymers. In the current work, we explore the influence of the side chains of the matrix polymer on the physical properties of the pure polymers and their corresponding c-SPBs, including electrical properties and phase transition behaviors. Six diketopyrrolopyrrole (DPP)-based polymers with pentamethylene conjugation-break spacers (CBSs) and various side chains, including branched-alkyl, triethylene glycol (TEG), and siloxane-terminated side chains, were synthesized and characterized. The UV–vis spectra show that the side chains have a noticeable impact on the intermolecular interactions in the solid states. In addition, side chains also have a significant influence on the thermal behaviors of the polymers. Polymers with as...

N-Type Organic Thermoelectrics: Improved Power Factor by Tailoring Host-Dopant Miscibility.

In this contribution, for the first time, the polarity of fullerene derivatives is tailored to enhance the miscibility between the host and dopant molecules. A fullerene derivative with a hydrophilic triethylene glycol type side chain (PTEG-1) is used as the host and (4-(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)phenyl)dimethylamine n-DMBI) as the dopant. Thereby, the doping efficiency can be greatly improved to around 18% (<1% for a nonpolar reference sample) with optimized electrical conductivity of 2.05 S cm-1 , which represents the best result for solution-processed fullerene derivatives. An in-depth microstructural study indicates that the PTEG-1 molecules readily form layered structures parallel to the substrate after solution processing. The fullerene cage plane is alternated by the triethylene glycol side chain plane; the n-DMBI dopants are mainly incorporated in the side chain plane without disturbing the π-π packing of PTEG-1. This new microstructure, which is rarely observed for codeposited thin films from solution, formed by PTEG-1 and n-DMBI molecules explains the increased miscibility of the host/dopant system at a nanoscale level and the high electrical conductivity. Finally, a power factor of 16.7 µW m-1 K-2 is achieved at 40% dopant concentration. This work introduces a new strategy for improving the conductivity of solution-processed n-type organic thermoelectrics.

Hydrophilic Poly(naphthalene diimide)‐Based Acceptor–Photosensitizer Dyads: Toward Water‐Processible Modular Photoredox‐Active Architectures

Hydrophilic naphthalene diimide based acceptor polymers are prepared by the incorporation of triethylene glycol or poly(ethylene glycol) side chains in the monomers and subsequent nitroxide‐mediated polymerization (NMP). The kinetic investigation of the polymerization reveals a controlled chain growth as well as a narrow molar mass distribution. Due to the utilization of a functional NMP initiator, a single Ru(II) photosensitizer unit is readily attached at the polymers chain terminus by a modular approach to construct water soluble photoredox‐active acceptor–photosensitizer dyads. The analysis of the optical properties by steady‐state absorption and emission spectroscopy reveals preserved optical absorption properties of the individual building blocks, and, more importantly, an efficient quenching of the Ru(II) emission assigned to intramolecular charge transfer from the complex to the acceptor polymer. The results demonstrate the versatility of side chain modifications to prepare water‐processible photoredox‐active architectures under preservation of the modular character known from hydrophobic systems. image

Trinuclear Ruthenium Macrocycles: Toward Supramolecular Water Oxidation Catalysis in Pure Water

The incorporation of a Ru(bda)(bda = 2,2′-bipyridine-6,6′-dicarboxylate) water oxidation catalyst into a trinuclear metallosupramolecular macrocycle leads to increased stability and activity compared to the mononuclear reference system. To overcome solubility problems of such large structures in water and the need for large amounts of organic cosolvents, new macrocyclic water oxidation catalysts with improved water solubility become desirable. With triethylene glycol side chains, the required amount of acetonitrile as a cosolvent was halved, whereas the application of charged ammonium side chains allowed catalysis in pure water. The catalytic activity was found to be comparable to the parent compound. Kinetic experiments were performed to explain the rate differences between those new derivatives and showed that Coulombic repulsion between the charged side chains and CeIV leads to slower oxidation processes.

Controlling the mode of operation of organic transistors through side-chain engineering

Electrolyte-gated organic transistors offer low bias operation facilitated by direct contact of the transistor channel with an electrolyte. Their operation mode is generally defined by the dimensionality of charge transport, where a field-effect transistor allows for electrostatic charge accumulation at the electrolyte/semiconductor interface, whereas an organic electrochemical transistor (OECT) facilitates penetration of ions into the bulk of the channel, considered a slow process, leading to volumetric doping and electronic transport. Conducting polymer OECTs allow for fast switching and high currents through incorporation of excess, hygroscopic ionic phases, but operate in depletion mode. Here, we show that the use of glycolated side chains on a thiophene backbone can result in accumulation mode OECTs with high currents, transconductance, and sharp subthreshold switching, while maintaining fast switching speeds. Compared with alkylated analogs of the same backbone, the triethylene glycol side chains shift the mode of operation of aqueous electrolyte-gated transistors from interfacial to bulk doping/transport and show complete and reversible electrochromism and high volumetric capacitance at low operating biases. We propose that the glycol side chains facilitate hydration and ion penetration, without compromising electronic mobility, and suggest that this synthetic approach can be used to guide the design of organic mixed conductors.