Suzuki Polymerization Reaction Research Articles

A novel fluorescent “Off-On” probe based on phenanthro[9,10-d]imidazole conjugated polymers (PIPF) for Cr3+ detection with high selectivity and sensitivity

Trivalent chromium (Cr3+) causes serious environmental pollution, degradation of the quality of edible agricultural products and human diseases. A novel phenanthro[9,10-d]imidazole-derived conjugated polymers (PIPF) was obtained from 4-(5,10-dibromo-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and diethyl 4,4′-(2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-fluorene-9,9-diyl)dibutyrate by Suzuki polymerization reaction, which was reasonably demonstrated by 1H NMR spectroscopy, infrared spectroscopy and quantum chemical calculations. The PIPF exhibits a “turn-on” fluorescence response to Cr3+ in DMSO/H2O (98:2, v/v) with naked-eye detection. The limit of detection for Cr3+ was calculated to be 0.073 μM with a linear range of 3–9 μM. The possible mechanism of the PIPF-based Cr3+ fluorescence “turn-on” sensor is due to the inhibition of the PET process by the coordination of Cr3+ to the hexaalkyl ester carbon chain of PIPF (RCOO-). The high sensitivity, good selectivity, and utility of this sensor indicated that PIPF-based “turn-on” fluorescence sensor is a potential fluorescence application for measuring Cr3+ in environmental samples.

Tandem Suzuki Polymerization/Heck Cyclization Reaction to Form Ladder-Type 9,9'-Bifluorenylidene-Based Conjugated Polymer.

The synthesis of ladder-type 9,9'-bifluorenylidene-based conjugated polymer is reported. Unlike the typical synthetic strategy, the new designed ladder-type conjugated polymer is achieved via tandem Suzuki polymerization/Heck cyclization reaction in one-pot. In the preparation process, Suzuki polymerization reaction occurred first and then the intramolecular Heck cyclization followed smoothly under the same catalyst Pd(PPh3)4. The model reaction proved that the introduction of iodine (I) for this tandem reaction can effectively control the sequential bond-forming process and inhibit the additional competitive side reactions. Thus, small-molecule model compounds could be obtained in high yields. The successes of the synthesized small molecule and polymer compounds indicate that the Pd-catalyzed tandem reaction may be an effective strategy for improving extended π-conjugated materials.

Selenophene‐containing conjugated polymers for supercapacitor electrodes

AbstractIn recent years, studies on conjugated polymers have strengthened the researchers' thought that such polymers can play an essential role in developing new generation energy storage devices. Hence conjugated polymer supercapacitor studies have accelerated. In the present work, selenophene‐containing conjugated polymers previously synthesized via palladium‐catalyzed Suzuki polymerization reaction were used in the preparation of conjugated polymer‐based supercapacitor electrodes. The structure and surface morphology of conjugated polymers were determined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The selenophene‐containing two conjugated polymer electrodes (ITO/Polymer) were fabricated. The electrochemical behavior of the conjugated polymer electrodes was evaluated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacity of ITO/CP1 electrode at 5 mV/s are 161.2 and 47 (Fg−1) for 0.1 mg and 1.2 mg, respectively. The specific capacity of ITO/CP2 at 5 mV/s electrode are 511 and 108.85 (Fg−1) for 0.08 mg and 0.70 mg, respectively. The time constants were determined as 10 and 625 ms for ITO/CP1 and CP2/ITO electrodes, respectively.

Liquid/Liquid Interfacial Suzuki Polymerization Prepared Novel Triphenylamine-Based Conjugated Polymer Films with Excellent Electrochromic Properties

Preparing conjugated polymer films via interfacial Suzuki polymerization is a promising method for obtaining desirable electrochromic materials with desired structures. Here, a series of aryl boronic esters and triphenylamine-based aryl bromides were applied as precursors, and several polymer films were finally obtained via the liquid/liquid interfacial Suzuki polymerization reaction under mild conditions. FT-IR, UV, and Raman as well as electrochemistry, SEM, and EDS results all provide strong evidence for the formation of the desired polymer structures. Among them, the TPA-Wu (containing triphenylamine and alkyl-fluorene) film exhibits the best film-forming quality. Besides, these polymer films were applied in electrochromic applications. The results show that electrochromic properties can be affected by the quality of film formation. It is worth mentioning that the TPA-Wu film could achieve excellent electrochromic properties with reversible multicolor changes from transparent yellow to orange-red to blue-green under varying potentials. Compared to other triphenylamine-based electrochromic materials, the TPA-Wu film possessed the most desirable coloring efficiency, higher optical contrast, and shorter switching time. This work provides an existing general approach of liquid/liquid interfacial Suzuki polymerization for constructing conjugated polymer films toward electrochromic applications.

Selenophene-bearing low-band-gap conjugated polymers: tuning optoelectronic properties via fluorene and carbazole as donor moieties

In this study, two donor–acceptor (D–A)-type conjugated polymers, namely PQSeCz and PQSeFl, were designed and synthesized. Selenophene was incorporated as the π-bridge and quinoxaline as an acceptor unit, while carbazole and fluorene were used as the donor units. Polymers were synthesized via palladium-catalyzed Suzuki polymerization reaction. All molecules were characterized by 1H and 13C NMR spectroscopy. The weight and number average molecular weights of the two polymers were determined by gel permeation chromatography. Electrochemical and spectroelectrochemical characterizations of the polymers were performed to investigate their optoelectronic properties. Oxidation potentials were 1.15 V/0.82 V and 1.11 V/0.82 V for PQSeCz and PQSeFl, respectively, while reduction potentials were − 1.26 V/− 1.14 V and − 1.48 V/− 1.20 V, respectively. In the visible region, maximum absorption wavelengths for the two polymers were 551 nm and 560 nm, respectively. Optical band gaps (Egop) were found from the lowest energy π–π∗ transition onsets as 1.67 eV for PQSeCz and 1.51 eV for PQSeFl, respectively. Both polymers showed good solubility in common solvents.

Effect of appended porphyrin in poly(fluorene-alt-benzothiadiazole): synthesis, characterization, physico-chemical and electrochemical studies

Poly(fluorene-alt-benzothiadiazole) having 5 and 10% equivalent meso-tetraphenylporphyrin (m-MTPCC) linked through oxyethylene spacer in carbazole (P2, P3) and the parent poly(9,9-di-hexylfluorene-alt-2,1,3-benzothiadiazole) (P1) were synthesized using Suzuki polymerization reaction. These polymers were characterized using FT-IR, 1H NMR, TGA and gel permeation chromatography. The synthesized polymers are soluble in common organic solvents and are found to be thermally stable. Weight average molecular weights of the polymers were 51.895, 71.224 and 34.789 kDa for P1, P2 and P3, respectively. These copolymers (P2 and P3) shows absorption maxima at around 320, 422, 452 nm and emission maxima at 540 nm in solution, whereas in film state, these polymers (P2 and P3) shows absorption maxima at around 322, 422, 466 and 554 nm and emission at around 539, 654 and 718 nm. The photoluminescence emission at 648 and 720 nm when excited at 320 nm shows that energy transfer from polymer backbone to porphyrin. Surface morphology, optical absorption and emission properties of these polymers with PCBM were also studied. Electrochemical characterization of these polymers shows deep HOMO levels for P2 and P3 when compared with parent polymer and the details are reported.

Effect of Co-monomers on Triphenylamine-Thiazolothiazole-Based Donor-Acceptor Copolymers: Synthesis and their Optical Properties

Donor-Acceptor type copolymer, poly(9,9-di-n-hexylfluorene-alt-2,5-bis(N,N-diphenylaniline)-thiazolo[5,4-d]thiazole) (P1) and random copolymers of P2-P4 have been synthesized using Suzuki polymerization reaction. For random copolymers, dicyanomethane derivative of triphenylamine, dithienothiophene and thienothiophene were used as co-monomers, respectively to P2-P4 along fluorene and 2,5-bis(N,N-diphenylaniline)-thiazolo[5,4-d]thiazole). Studies on the optical, thermal and electrochemical properties of these copolymers (P1-P4) were carried out. By incorporating different aromatic moiety as co-monomer, optical properties of the polymers were tuned which exhibited significant changes in UV-Vis absorption as well as emission characteristics. All these copolymers were thermally stable upto 300 °C and soluble in common organic solvents. Electrochemical studies of these polymers indicate that they have deep HOMO energy levels. Photoluminescence emission studies of the synthesized polymers as thin film showed that polymer (P2) with dicyanomethane derivative of triphenylamine was red shifted when compared with other polymers. Weight average moleular weights of the polymers were in the range of 6.457 KDa to 12.000 KDa.

Synthesis and chemosensory properties of two-arm truxene-functionalized conjugated polyfluorene containing terpyridine moiety

We report the responsive fluorescence chemosensory phenomena of a truxene-functionalized conjugated polymer (P1) with pendant terminal terpyridine (tpy) groups as receptors for metal ions synthesized via a Suzuki polymerization reaction.

Second-order nonlinear optical hyperbranched polymer containing isolation chromophore moieties derived from both “H”-type and star-type chromophores

An NLO hyperbranched polymer (HP1) derived from both “H”-type and star-type chromophores was synthesized successfully for the first time with high yield via one-pot “A2 + B3” Suzuki polymerization reaction. Isolation chromophore was also introduced to further improve its performance. Although under the test conditions, the films of HP1 could not be poled completely, it still demonstrated satisfactory macroscopic NLO effect with the second harmonic generation (SHG) coefficient d 33 value of 36 pm/V.

A functional conjugated hyperbranched polymer derived from tetraphenylethene and oxadiazole moieties: Synthesis by one-pot “a4+b2+c2” polymerization and applicaion as explosive chemosensor and pled

A new conjugated hyperbranched polymer (hb-TFO) containing tetraphenylethylene (TPE) units, a famous aggregation-induced emission (AIE) active group, as the core, was synthesized successfully with modest yield via one-pot Suzuki polymerization reaction. Thanks to the introduction of TPE moieties, hb-TFO exhibited aggregation-enhanced emission (AEE) property, and could work as explosive chemosensor with high sensitivity. The polymeric light-emitting diode (PLED) device was fabricated to investigate its electroluminescent property, and hb-TFO demonstrated a maximum luminance efficiency of 0.22 cd/A and a maximum brightness of 545 cd/m2 at 15.9 V.

Microwave‐assisted suzuki coupling reaction for rapid synthesis of conjugated polymer–poly(9,9‐dihexylfluorene)s as an example

AbstractLong reaction period (dozens of hours) is often required for the synthesis of conjugated polymers by palladium‐catalyzed Suzuki polymerization reaction. This work shows that microwave can accelerate Suzuki polymerization to realize the ultra‐rapid synthesis of conjugated polymers, here poly(9,9‐dihexylfluorene)s (PDHFs) as an example. The effects of reaction conditions on the polymerization have been systematically investigated, including the mode of microwave irradiation, microwave power, reaction temperature, reaction time, solvents, catalyst species, and catalyst concentrations. Compared with the conventional heating method (oil bath) for the synthesis of PDHFs (48 h, Mw = 20,000 g/mol), Suzuki polymerization under optimized microwave condition can yield PDHFs with higher molecular weight (Mw = 40,000 g/mol) in a much shorter time (14 min). The structures of obtained PDHFs samples are fully characterized spectroscopically, demonstrating well‐defined PDHFs have been prepared through microwave‐assisted (MA) Suzuki polymerization reaction. In addition, the mechanism of MA Suzuki polymerization is proposed preliminarily. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Synthesis of new near infrared absorption polymers based on thiadiazoloquinoxaline and their solar cell applications

Two new alternating copolymers comprising 4,6,7,9-tetra(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline and 6,6′,12,12′-tetraoctyl-6,12-dihyroindeno[1,2-b]fluorene (PIFDQ) or 9,9-dioctyl-9H-fluorene (PFDQ) were synthesized via Suzuki polymerization reaction. The optical and electrochemical properties of polymers PIFDQ and PFDQ were found to be quite similar, and their absorption bands were extended from 250nm to 1100nm in film. The optical band gaps of the polymers were calculated from the onset wavelength of absorption to be 1.19eV and 1.16eV, respectively. The energy conversion ability of the synthesized polymers was tested by making single layer BHJ solar cells with the configuration of ITO/PEDOT:PSS/PIFDQ or PFDQ:PC70BM (1:5, wt%)/TiOx/Al. The overall photovoltaic performance of the device based on PIFDQ was found to be 0.27% with a Voc of 0.41V, a Jsc of 2.39mA/cm2, and a FF of 28%, while the device made from PFDQ showed power conversion efficiency (PCE) of 0.16% with a Voc of 0.43V, a Jsc of 1.30mA/cm2, and a FF of 28%.

New Hyperbranched Conjugated Polymers Containing Hexaphenylbenzene and Oxadiazole Units: Convenient Synthesis and Efficient Deep Blue Emitters for PLEDs Application

In this article, four "A(3)+B(2)+C(2)"-type hyperbranched conjugated polymers (P1-P4) containing hexaphenylbenzene as the core were synthesized successfully for the first time with high yields through one-pot Suzuki polymerization reaction. The copolymerization percent of 1,3,4-oxadiazole units was adjusted to investigate the effect of polymer composition on the physical, optical, and EL properties. All polymers were well-characterized and exhibited good solubility, film-forming ability, and thermal stability. Both the solution and the films of these hyperbranched polymers emitted pure and stable deep-blue light emission, and their PL spectra did not change after annealing at 150 degrees C for 0.5 h in air, indicating that the hyperbranched structure, coupled to the introduced hexaphenylbenzene moieties, effectively suppressed the formation of aggregation excimer and keto defects. Two-layer PLED devices were fabricated to investigate the electroluminescence properties of these hyperbranched polymers, and P3 demonstrated a maximum luminance efficiency of 0.72 cd/A and a maximum brightness of 549 cd/m(2) at 16.5 V.

A new intramolecular donor–acceptor polyfluorene copolymer for bulk heterojunction solar cells

We have synthesized a new low bandgap alternating polyfluorene copolymer (PFNAP) based on dioctylfluorene and a donor–acceptor monomer with an electron-withdrawing moiety as a side chain, via a Suzuki polymerization reaction. The resulting copolymer has low optical and electrochemical bandgaps. The optical bandgap and the electrochemical bandgap of PFNAP are 1.82 and 1.89 eV, respectively. The bulk heterojunction polymer solar cells were fabricated with the conjugated polymer as the electron donor and 6,6-phenyl C 61-butyric acid methyl ester (PCBM) as the electron acceptor. The power conversion efficiencies (PCE) of the solar cells based on PFNAP:PCBM (1:3) and PFNAP:PCBM (1:4) are 0.61% and 0.67%, respectively, under the illumination of AM 1.5 G, 100 mW/cm 2.

Synthesis and characterization of new low bandgap polyfluorene copolymers for bulk heterojunction solar cells

AbstractTwo new low bandgap alternating polyfluorene copolymers based on dioctylfluorene and donor‐acceptor‐donor monomers have been synthesized via a Suzuki polymerization reaction. The resulting copolymers have low optical bandgaps at 1.99–1.98 eV. The bulk heterojunction polymer solar cells were fabricated with the conjugated polymers as the electron donor and 6.6‐phenyl C61‐butyric acid methyl ester as the electron acceptor. The power conversion efficiencies of the solar cells based on copolymers 1 and 2 are 0.37 and 0.42%, respectively, under the illumination of AM 1.5, 100 mW/cm2. The results indicate that the two copolymers are promising conjugated polymers for polymer solar cells. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5336–5343, 2009

Electroluminescent fluorene-based alternating polymers bearing triarylamine or carbazole moieties in the main chain: Synthesis and properties

Two soluble conjugated polyfluorenes, poly{9,9-dioctylfluorene-2,7-diyl-co-4,4′-bis[2-(4-phenyl)-2-cyanovinyl]triphenylamine}(PF-BCT) and poly{9,9-dioctylfluorene-2,7-diyl-co-3,6-bis[2-(4-phenyl)-2-cyanovinyl]-9-octyl carbazole}(PF-BCC), have been synthesized from 2,7-dibromo-9,9-dioctylfluorene and 4,4′-bis[2-(4-bromophenyl)- 2-cyanovinyl]triphenylamine or 3,6-bis[2-(4-bromophenyl)-2-cyanovinyl]-9-octyl carbazole comonomers through a Suzuki polymerization reaction. The copolymers are characterized by gel permeation chromatography, elemental analysis, thermogravimetric analysis. The polymers have good thermal stability with 5 wt % loss temperatures of more than 380°C. Cyclic voltammetry measurements show that the polymers present good electron and hole-injection abilities. PF-BCC possesses higher oxidization potential than that of PF-BCT, which indicates that PF-BCT has better hole injection ability. The photophysical properties of the polymers are investigated in both solutions and spinning-coated films. Compared to that of PF-BCC, the absorption and emission peaks of PF-BCT bathochromic shift in the solid film or solution states. Single layer light-emitting devices have been fabricated in the ITO/PEDOT: PSS/polymer/Ca/Al configuration. The electroluminescence (EL) device based on PF-BCT shows yellow emission with the current efficiency of 0.21 cd/A, while PF-BCC shows greenish yellow emission with the current efficiency of 0.08 cd/A. In addition, to improve the electroluminescence of PF-BCC, a PVK layer is introduced, the brightness and efficiency get improved to 700 cd/m2 and 0.12 cd/A, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009