Suzuki Polycondensation Research Articles

Thiophene‐Based Multi‐layered 3D Chiral Polymer and Oligomer Containing Aggregate‐Induced Emission and Polarization

AbstractThiophene‐based conjugated polymers show a unique position in the constantly expanding variety of conjugated polymers because of their outstanding optical and conductive characteristics. during the past few decades, many researchers have made significant contributions by developing new methods to create more effective materials for electronic applications. Employing one‐pot Suzuki polycondensation, a unique series of structurally condensed multicolumn/multilayer 3D polymers and oligomers have been developed and synthesized in this research. Polymers were produced with moderate to excellent yields in all instances, as examined by GPC and 1H‐NMR. The results from experiments of optical rotation and AIE investigation, show that the current work will benefit materials research and applications.

Precise Modulation of Circularly Polarized Luminescence via Polymer Chiral Co‐assembly and Contactless Dynamic Chiral Communication

AbstractCircularly polarized luminescence (CPL) plays a pivotal role in cutting‐edge display and information technologies. Currently achieving precise color control and dynamic signal regulation in CPL still remains challenging due to the elusory relationship between fluorescence and chirality. Inspired by the natural mechanisms governing color formation and chiral interaction, we proposed an addition‐subtraction principle theory to address this issue. Three fluorene‐based polymers synthesized by Suzuki polycondensation with different electron‐deficient monomers exhibit similar structures and UV/Vis absorption, but distinct fluorescence emissions due to intramolecular charge transfer. Based on this, precise‐color CPL‐active films are obtained through quantitative supramolecular co‐assembly directed by addition principle. Particularly, an ideal white‐emitting CPL film (CIE coordinates: (0.33, 0.33)) is facilely fabricated with a high quantum yield of 80.8 % and a dissymmetry factor (glum) of 1.4×10−2. Structural analysis reveals that the ordered stacking orientation favors higher glum. Furthermore, to address the dynamically regulated challenge, the comparable subtraction principle is proposed, involving a contactless chiral communication between excited and ground states. The representative system consisting of as‐prepared fluorene‐based polymers and chirality‐selective absorption azobenzene (Azo)‐containing polymers is constructed, achieving CPL weakening, reversal, and enhancement. Finally, a switchable quick response code is realized based on trans‐cis isomerization of Azo moiety.

Precise Modulation of Circularly Polarized Luminescence via Polymer Chiral Co-assembly and Contactless Dynamic Chiral Communication.

Circularly polarized luminescence (CPL) plays a pivotal role in cutting-edge display and information technologies. Currently achieving precise color control and dynamic signal regulation in CPL still remains challenging due to the elusory relationship between fluorescence and chirality. Inspired by the natural mechanisms governing color formation and chiral interaction, we proposed an addition-subtraction principle theory to address this issue. Three fluorene-based polymers synthesized by Suzuki polycondensation with different electron-deficient monomers exhibit similar structures and UV/Vis absorption, but distinct fluorescence emissions due to intramolecular charge transfer. Based on this, precise-color CPL-active films are obtained through quantitative supramolecular co-assembly directed by addition principle. Particularly, an ideal white-emitting CPL film (CIE coordinates: (0.33, 0.33)) is facilely fabricated with a high quantum yield of 80.8 % and a dissymmetry factor (glum) of 1.4×10-2. Structural analysis reveals that the ordered stacking orientation favors higher glum. Furthermore, to address the dynamically regulated challenge, the comparable subtraction principle is proposed, involving a contactless chiral communication between excited and ground states. The representative system consisting of as-prepared fluorene-based polymers and chirality-selective absorption azobenzene (Azo)-containing polymers is constructed, achieving CPL weakening, reversal, and enhancement. Finally, a switchable quick response code is realized based on trans-cis isomerization of Azo moiety.

Design of Novel Functional Conductive Structures and Preparation of High-Hole-Mobility Polymer Transistors by Green Synthesis Using Acceptor-Donor-Acceptor Strategies.

The design of novel acceptor molecular structures based on classical building blocks is regarded as one of the efficient ways to explore the application of organic conjugated materials in conductivity and electronics. Here, a novel acceptor moiety, thiophene-vinyl-diketopyrrolopyrrole (TVDPP), was envisioned and prepared with a longer conjugation length and a more rigid structure than thiophene-diketopyrrolopyrrole (TDPP). The brominated TVDPP can be sequentially bonded to trimethyltin-containing benzo[c][1,2,5]thiadiazole units via Suzuki polycondensation to efficiently prepare the polymer PTVDPP-BSz, which features high molecular weight and excellent thermal stability. The polymerization process takes only 24 h and eliminates the need for chlorinated organic solvents or toxic tin-based reagents. Density functional theory (DFT) simulations and film morphology analyses verify the planarity and high crystallinity of the material, respectively, which facilitates the achievement of high carrier mobility. Conductivity measurements of the polymeric material in the organic transistor device show a hole mobility of 0.34 cm2 V-1 s-1, which illustrates its potential for functionalized semiconductor applications.

Proton-Conducting Membranes from Polyphenylenes Containing Armstrong's Acid.

This study demonstrates the use of 1,5-naphthalenedisulfonic acid as a suitable building block for the efficient and economic preparation of alternating sulfonated polyphenylenes with high ion-exchange capacity (IEC) via Suzuki polycondensation. Key to large molar masses is the use of an all-meta-terphenyl comonomer instead of m-phenyl, the latter giving low molar masses and brittle materials. A protection/deprotection strategy for base-stable neopentyl sulfonates is successfully implemented to improve the solubility and molar mass of the polymers. Solution-based deprotection of polyphenylene neopentyl sulfonates at 150 °C in dimethylacetamide eliminates isopentylene quantitatively, resulting in membranes with high IEC (2.93 mequiv/g) and high proton conductivity (σ = 138 mS/cm). Water solubility of these copolymers with high IEC requires thermal cross-linking to prevent their dissolution under operating conditions. By balancing the temperature and time of the cross-linking process, water uptake can be restricted to 50 wt %, retaining an IEC of 2.33 mequiv/g and a conductivity of 85 mS/cm. Chemical stability is addressed by treatment of the membranes under Fenton's conditions and by considering barrier heights for desulfonation using density functional theory (DFT) calculations. The DFT results suggest that 1,5-disulfonated naphthalenes are at least as stable as sulfonated polyphenylenes against desulfonation.

PdNPs/NiNWs as a welding tool for the synthesis of polyfluorene derivatives by Suzuki polycondensation under microwave radiation

Conjugated polymers are promising tools to differentiate various types of semiconducting single-walled carbon nanotubes (s-SWCNTs). However, their synthesis is challenging. Insufficient control over molecular weights, and unpredictive/unrepeatable batches hinder possible applications and scale-up. Furthermore, commercial homogeneous catalysts often require inert conditions and are almost impossible to recycle. To overcome these problems, we present a nanocatalyst consisting of magnetic nickel nanowires decorated with highly active palladium nanoparticles. A two-step wet chemical reduction protocol with the assistance of sonochemistry was employed to obtain a heterogeneous catalyst capable of conducting step-growth Suzuki polycondensation of a fluorene-based monomer. Additionally, we enhanced the performance of our catalytic system via controlled microwave irradiation, which significantly shortened the reaction time from 3 d to only 1 h. We studied the influence of the main process parameters on the yield and polymer chain length to gain insight into phenomena occurring in the presence of metallic species under microwave irradiation. Finally, the produced polymers were used to extract specific s-SWCNTs by conjugated polymer extraction to validate their utility.

“Diluting branches” put to work: from synthesis to properties control of multifunctional polymers derived from triphenylamine, fluorene and thiophene

A series of highly branched polymers was synthesized by Suzuki polycondensation of thiophene-, fluorene-, and triphenylamine-based monomers, following the “A2 + B2 + C3” pathway. A “dilution of branches” approach...

Synthesis, Photo- and Electroluminescence of New Polyfluorene Copolymers Containing Dicyanostilbene and 9,10-Dicyanophenanthrene in the Main Chain.

Using palladium-catalyzed Suzuki polycondensation, we synthesized new light-emitting fluorene copolymers containing the dicyano derivatives of stilbene and phenanthrene and characterized them by gel permeation chromatography, UV-vis absorption spectroscopy, spectrofluorimetry, and cyclic voltammetry. The photoluminescence spectra of the synthesized polymers show significant energy transfer from the fluorene segments to the dicyanostilbene and 9,10-dicyanophenanthrene units, which is in agreement with the data of theoretical calculations. OLEDs based on these polymers were fabricated with an ITO/PEDOT-PSS (35 nm)/p-TPD (30 nm)/PVK (5 nm)/light emitting layer (70-75 nm)/PF-PO (20 nm)/LiF (1 nm)/Al (80 nm) configuration. Examination of their electroluminescence revealed that copolymers of fluorene with dicyanostilbene show yellow-green luminescence, while polymers with 9,10-dicyanophenanthrene have a greenish-blue emission. The 9,10-dicyanophenanthrene units have a more rigid structure compared to dicyanostilbene and, in OLEDs based on them, an increase in maximum brightness is observed with an increase in the content of the additive to the polymer chain. In particular, the device using fluorene copolymer with 9,10-dicyanophenanthrene (2.5 mol%) exhibited a maximum brightness of 9230 cd/m2 and a maximum current efficiency of 3.33 cd/A.

Water‐soluble π‐conjugated polyfluorene bearing 6‐N1‐hexylcytosine and 6‐trimethylammoniumhexyl side chains: Synthesis, chemical properties, and sensing ability for nucleoside and telomere DNA

AbstractWater‐soluble π‐conjugated polyfluorene bearing 6‐N1‐cytosinehexyl and 6‐trimethylammoniumhexyl bromide side chains, namely polymer‐1, was synthesized by Suzuki polycondensation. The absorption onset wavelength (λonset) of the polymer was longer than that of the monomer and confirmed the presence of the π‐conjugated system along the polymer chain. The cyclic voltammetry and UV–vis analyses showed that the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of the polymer were −5.5 and −2.6 eV, respectively. The photoluminescence (PL) intensity of the polymer decreased with increasing DNA chain length (m) upon adding (TTAGGG)m (T = thymine, A = adenine, and G = guanine; m = 2, 4, 6, and 8), indicating that the polymer could detect telomere DNA chain lengths with higher precision than previously reported DNA sensors. Similarly, the PL intensity decreased with the addition of nucleosides. Photoinduced charge transfer in the complex between the polymer and DNA or nucleoside played an important role in the PL response of the polymer toward analytes. The sensing behavior was analyzed using the Stern–Volmer and Benesi–Hildebrand methods.

Carbazole-Pyridazine copolymers and their rhenium complexes: Effect of the molecular structure on the electronic properties

Two new push–pull copolymers, poly[N-(9-heptadecanyl)carbazole-2,7-diyl-alt-phthalazine- 5,8-diyl] (P1) and poly[N-(9-heptadecanyl)carbazole-2,7-diyl-alt-thieno[3,4-d]pyridazine- 5,7-diyl] (P2), were synthetized by means of a Suzuki polycondensation. The molecular characterization with 1H NMR and MALDI-MS showed enchainment defects in the polymer backbones depending on the synthetic conditions (catalyst and temperature). Both carbazole-carbazole and diazine-diazine homocoupling defects occurred, particularly in the case of P2. For P1, instead, almost homocoupling-free material was obtained. Exploiting the metal coordination capability of the pyridazine ring, corresponding dinuclear rhenium-based metallopolymers, ReP1 and ReP2, were also synthetized. All materials were investigated with experimental techniques (UV–vis spectroscopy, photoluminescence, cyclic voltammetry) and corroborated by theoretical studies (DFT and TD-DFT), including a qualitative evaluation of the effects of backbone defects on the electronic properties of the polymers. They were also tested in organic photovoltaic (OPV) devices. The wide energy gaps (Eg) accompanied with a low absorption coefficient for the band in the visible range reduced the harvesting capability of the copolymers. These drawbacks were partially overcome in the metallopolymers. The low device performance was mainly attributable to the low solubility of the metallopolymers in the organic solvents.

A pyridinyl-phenanzine conjugated microporous polymer decorated with ultrafine Ag nanoparticles mediates the rapid reduction of nitrophenol

In this study we used classical Suzuki polycondensation to prepare a pyridinyl-phenanzine (TPPQP) conjugated microporous polymer (CMP) that featured a spherical morphology with a large surface area (371 m2 g−1) and high thermal stability (Td10 = 625 °C; char yield = 81.7 wt%). The framework of the TPPQP CMP presented many dynamic pyridinic units could capture Ag+ ions from solution and facilitate their self-reduction to Ag nanoparticles, thereby forming [email protected] CMP nanocatalysts. The [email protected] CMP nanocatalysts were strong reducing agents for pollutant nitrophenols, converting them into safe amino forms at standard temperature and pressure with a high normalized rate of 19.4 mg−1 s−1. The pyridinic units in the TPPQP CMP structure played an important role in the catalytic reaction, interacting with the phenolic OH groups of p-nitrophenol to accelerate the reduction.

Conjugated microporous polymer bearing 1,3,4-oxadiazole and thienyl moieties for decomposition of organic dyes under visible light

Conjugated microporous polymers (CMPs), as heterogeneous catalysts, have been studied intensively in the past few years. Here we reported two rationally designed and synthesized novel CMPs as the photocatalysts for degradation of organic dyes. The CMPs were synthesized by typical Suzuki polycondensation method and confirmed by FTIR and 13C solid-state NMR. The band gap energies of both CMPs were 3.1 eV for Ph(PhXOD)3-CMP and 2.5 eV for Ph(ThXOD)3-CMP, respectively, calculated by UV–vis spectra, indicating that the latter could be activated by visible light. The BET results showed that the Ph(PhXOD)3-CMP (349.3 m2/g) had much higher surface areas than that of Ph(ThXOD)3-CMP (78.2 m2/g). The photodegradation of organic dyes experiments showed that the Ph(PhXOD)3-CMP only presented photocatalytic ability on the condition of ultraviolet irradiation due to lack of absorption in visible light region. While Ph(ThXOD)3-CMP exhibited a relatively strong photocatalytic ability to initiate degradation of RhB and MB dye solution with visible light irradiation. Specifically, the RhB solution (10 mg/L) could be decolorized in 150 min when Ph(ThXOD)3-CMP was used as the photocatalyst under visible light. The mechanism study including adding-scavenger method, NBT method and ESR characterization showed that the superoxide anion radical was the dominant active species during photodegradation of RhB. This research was expected to inspire more research interest in the rational design of CMPs for photodegradation of organic dyes.

Hyperbranched Polyphenylene as an Electrode for Li‐Ion Batteries

Polymeric electrodes have attracted considerable attention for their potential as Li‐ion battery (LIB) electrodes due to their tunable structures and sustainable preparation from abundant precursors in an environmentally friendly manner. Herein, hyperbranched polyphenylene (HBP) is synthesized through Suzuki polycondensation and investigated as a potential bipolar electrode for LIBs. The advantages of the hyperbranched architecture in HBP include easy and fast transportation of ions as an electrode. Brunauer–Emmett–Teller (BET) measurement on HBP reveals a high specific surface area and porosity compared with typical linear polymers. The low conductivity in HBP is improved by preparing an HBP/multiwalled carbon nanotube (MWCNT) composite material. The LIB performance for the HBP/MWCNT composite anode electrode shows good cyclic stability and high specific capacity, which are caused by the branching architecture, surface area, and improved electronic conductivity from the MWCNT. This results in easy access and rapid movement of Li ions for improved charge–discharge performance. The ex situ technique using Fourier transform infrared spectroscopy shows a lithium storage mechanism in the HBP electrode. This work shows extensive scope for using the hyperbranched architectural concept to explore and develop high‐performing organic electrodes for future metal‐ion batteries.

Impact of Synthetic Route on Photovoltaic Properties of Isoindigo‐Containing Conjugated Polymers

AbstractHerein, the synthesis of a novel isoindigo‐based conjugated polymer using Suzuki and Stille polycondensation reactions is reported. It is shown that the polymer obtained using various reactions possesses different performance in photovoltaic devices. In particular, polymers synthesized using Suzuki and Stille polycondensation demonstrate 2.7% and 4.1% efficiency in organic solar cells, and 12.6% and 15.1% in perovskite solar cells, respectively. The observed difference in the performances of devices is attributed to the appearance of defects in the polymer obtained via Suzuki reaction. Using high‐performance liquid chromatography it is demonstrated that the origin of the polymer quality deterioration is the poor stability of isoindigo‐based monomer under conditions of Suzuki polycondensation. Revealing this aspect allows one to figure out a more effective approach for the synthesis of high‐quality isoindigo‐based polymers for organic electronics.

Fluorene-containing polyhedral oligomericsilsesquioxanes modified hyperbranched polymer for white light-emitting diodes with ultra-high color rendering index of 96

In this work, a series of hyperbranched white-emitting conjugated polymers were synthesized with polyfluorene (PF) as the branches and three-dimensional-structured spiro[3.3]heptane-2,6-dispirofluorene (SDF) as the conjugated branching point by one-pot Suzuki polycondensation, where 4,7-dithienyl-2,1,3-benzothiadiazole (DBT) as orange-light emitting unit and fluorene-containing polyhedral oligomericsilsesquioxanes (POSSs) as conjugated linking monomer were introduced into the backbones to obtain white-light emission. The influence mechanism of POSSs for hyperbranched white-emitting polymers was explored by adjusting the feeding ratios of fluorene-containing POSSs (from 1 to 20 ​mol%). The results indicated that the synthesized polymers still maintained the high thermal stabilities, and exhibited the improved amorphous film morphology and hydrophobicity, which were beneficial for obtaining optimized interface between the aqueous hole transport layer Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT: PSS) layer and polymer light-emitting layer in device fabrication. As a consequence, all of the fabricated devices with the hyperbranched polymers as light-emitting layers realized white light-emission, and the optimized device exhibite good electroluminescent (EL) performance with Commission Internationale de l’Eclairage (CIE) coordinates at (0.32, 0.33) and maximum color rendering index (CRI) of 96. The fluorene-containing POSSs modified hyperbranched copolymers with broad full width at half maximum (>284 ​nm) are attractive candidates for sunlight-style white polymer light-emitting diodes.

A fluorescent covalent triazine framework consisting of donor–acceptor structure for selective and sensitive sensing of Fe3+

A covalent triazine framework (FL-CTF) consisting of electron-donating thiophene units and electron-accepting benzothiadiazole units was synthesized using Suzuki polycondensation. The successful polymerization and chemical structure of FL-CTF were revealed by a combination of FTIR, solid-state 13C NMR, and XPS. The as-prepared FL-CTF with donor–acceptor structure shows fluorescence property in DMF. A series of fluorescent measurements were performed to ascertain the sensing property of FL-CTF toward metal ions. The fluorescence quenching appears upon addition of Fe3+ and the fluorescence intensity recovers facilely after the addition of a chelating agent tetrabutylammonium fluoride. To understand the fluorescence quenching and recovery process, UV–Vis absorption spectra and XPS were further measured. The electron transfer from FL-CTF to electron-deficient Fe3+ and the interaction between Fe3+ and nitrogen sites in FL-CTF may lead to fluorescence quenching. The interference experiments indicated that FL-CTF can selectively detect Fe3+ in the presence of other metal ions or different counter anions. Moreover, FL-CTF can detect Fe3+ with high sensitivity with the detection limit of 0.78 μM. These results demonstrate that FL-CTF has high selectivity and sensitivity toward Fe3+ and thus is expected to be a fluorescent sensor in practical applications.

A mechanistic investigation of the Suzuki polycondensation reaction using MS/MS methods

The Suzuki polycondensation can be studied in real time using MS/MS methods, even with the molecular weight of the reaction components changing with every turnover.

Triple-Columned and Multiple-Layered 3D Polymers: Design, Synthesis, Aggregation-Induced Emission (AIE), and Computational Study.

Conjugated polymers and oligomers have great potentials in various fields, especially in materials and biological sciences because of their intriguing electronic and optoelectronic properties. In recent years, the through-space conjugation system has emerged as a new assembled pattern of multidimensional polymers. Here, a novel series of structurally condensed multicolumn/multilayer 3D polymers and oligomers have been designed and synthesized through one-pot Suzuki polycondensation (SPC). The intramolecularly stacked arrangement of polymers can be supported by either X-ray structural analysis or computational analysis. In all cases, polymers were obtained with modest to good yields, as determined by GPC and 1H-NMR. MALDI-TOF analysis has proven the speculation of the step-growth process of this polymerization. The computational study of ab initio and DFT calculations based on trimer and pentamer models gives details of the structures and the electronic transition. Experimental results of optical and AIE research confirmed by calculation indicates that the present work would facilitate the research and applications in materials.

Click-Functionalization of a Poly(Tetrazine-co-Fluorene)-Conjugated Polymer with a Series of trans-Cyclooctene Derivatives.

A soluble poly(tetrazine) polymer was prepared via Suzuki polycondensation of 3,6-bis(5-bromofuran-2-yl)-1,2,4,5-tetrazine and a fluorene diboronate derivative. It can undergo efficient and quantitative post-polymerization inverse-electron-demand Diels-Alder click reactions with a variety of trans-cyclooctene (TCO) derivatives. The resulting polymers were oxidized to convert dihydropyridazine rings into pyridazines. The absorption spectra of the product polymers, both before and after oxidation, showed hypsochromic shifts that correlated with steric hindrance of the appended side chains. They also exhibited a significantly enhanced fluorescence intensity relative to the original poly(tetrazine). While gel-permeation chromatography indicated that the product polymers exhibited longer retention times, NMR end-group analysis showed that the polymers retained relatively constant degrees of polymerization. Graft copolymers were easily prepared via reaction with TCO-functionalized poly(ethylene glycol) chains and a cross-linked foam was produced by reacting the poly(tetrazine) with a bis-TCO crosslinker.

Click‐Functionalization of a Poly(Tetrazine‐co‐Fluorene)‐Conjugated Polymer with a Series of trans‐Cyclooctene Derivatives

AbstractA soluble poly(tetrazine) polymer was prepared via Suzuki polycondensation of 3,6‐bis(5‐bromofuran‐2‐yl)‐1,2,4,5‐tetrazine and a fluorene diboronate derivative. It can undergo efficient and quantitative post‐polymerization inverse‐electron‐demand Diels–Alder click reactions with a variety of trans‐cyclooctene (TCO) derivatives. The resulting polymers were oxidized to convert dihydropyridazine rings into pyridazines. The absorption spectra of the product polymers, both before and after oxidation, showed hypsochromic shifts that correlated with steric hindrance of the appended side chains. They also exhibited a significantly enhanced fluorescence intensity relative to the original poly(tetrazine). While gel‐permeation chromatography indicated that the product polymers exhibited longer retention times, NMR end‐group analysis showed that the polymers retained relatively constant degrees of polymerization. Graft copolymers were easily prepared via reaction with TCO‐functionalized poly(ethylene glycol) chains and a cross‐linked foam was produced by reacting the poly(tetrazine) with a bis‐TCO crosslinker.