Development of Synthetic Method for ^|^pi;-Conjugated Polymers via Direct Arylation Polycondensation

Kuwabara, Junpei; Kanbara, Takaki

doi:10.5059/yukigoseikyokaishi.72.1271

Cited by 23 publications

(16 citation statements)

References 95 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[1][2][3][4][5][6] Recently, several groups have attempted to utilize this reaction in polycondensation for the synthesis of p-conjugated polymers that are considered promising materials for optoelectronic devices such as organic photovoltaic cells, field effect transistors, and light emitting diodes [Scheme 1(a)]. [7][8][9][10][11][12][13][14][15][16] However, this polycondensation reaction still requires prior preparation of dihalogenated aromatic monomers as coupling partners: Introduction of C-Br groups into the corresponding aromatic compounds and purification of the dibrominated aromatic monomers would involve extra synthetic steps. These observations prompted our interest in the facile synthesis of p-conjugated polymers via sequential bromination and direct arylation polycondensation [Scheme 1(b)]; this protocol enables the use of each aromatic monomer without preintroduction of reactive C-Br bonds as well as organometallic functional groups.…”

mentioning

confidence: 99%

Facile synthesis of fluorene-based π-conjugated polymers via sequential bromination/direct arylation polycondensation

Saitô

Kuwabara

Kanbara

2015

J. Polym. Sci. Part A: Polym. Chem.

Self Cite

View full text Add to dashboard Cite

INTRODUCTION Catalytic direct arylation of aromatic compounds via cleavage of C-H bonds has attracted increasing attention as a simple synthetic method that helps eliminate prior preparations of organometallic reagents. [1][2][3][4][5][6] Recently, several groups have attempted to utilize this reaction in polycondensation for the synthesis of p-conjugated polymers that are considered promising materials for optoelectronic devices such as organic photovoltaic cells, field effect transistors, and light emitting diodes [Scheme 1(a)]. [7][8][9][10][11][12][13][14][15][16] However, this polycondensation reaction still requires prior preparation of dihalogenated aromatic monomers as coupling partners: Introduction of C-Br groups into the corresponding aromatic compounds and purification of the dibrominated aromatic monomers would involve extra synthetic steps. These observations prompted our interest in the facile synthesis of p-conjugated polymers via sequential bromination and direct arylation polycondensation [Scheme 1(b)]; this protocol enables the use of each aromatic monomer without preintroduction of reactive C-Br bonds as well as organometallic functional groups. We thus explored an efficient bromination reaction and employed it for the bromination of arenes with quaternary ammonium tribromide; the reaction proceeded smoothly under mild conditions, giving the desired bromoarenes in good yields. 17-22 9,9-Dioctylfluorene is an appropriate targeting monomer because 2,7-dibromo-9,9dioctylfluorene possesses good reactivity toward the direct arylation polycondensation and high selectivity against side reactions; accordingly, a variety of fluorene-based p-conjugated polymers have been synthesized. 15,[23][24][25][26][27][28][29][30][31][32] We herein report the synthesis of fluorene-based p-conjugated polymers via sequential bromination of 9,9-dioctylfluorene and Pd-catalyzed direct arylation polycondensation.The following two conditions must be satisfied for sequential bromination and Pd-catalyzed direct arylation polycondensation.Each reaction should efficiently proceed, and residues and/ or byproducts originating from the bromination reaction step should have negligible impact on the successive polycondensation step. For instance, bromination of aromatic compounds has been generally carried out with bromine or N-bromosuccinimide (NBS) [33][34][35] ; however, the residual bromine and/or the produced byproducts such as succinimide are considered to inhibit the following direct arylation. In contrast, bromination with benzyltrimethylammonium tribromide (BTMA Br 3 ) [17][18][19]21,22 was expected to be preferable for our protocol; the solid brominating agent allows for accurate stoichiometric reaction, and benzyltrimethylammonium bromide (BTMA Br), a byproduct of the bromination, dose not inhibit the successive polycondensation step because tetraalkylammonium halides have been often used as a phase transfer catalyst in polycondensation processes. 7,12,[36][37][38] Therefore, we began our investigation with dibrominati...

show abstract

mentioning

confidence: 99%

Facile synthesis of fluorene-based π-conjugated polymers via sequential bromination/direct arylation polycondensation

Saitô

Kuwabara

Kanbara

2015

J. Polym. Sci. Part A: Polym. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…9,2628 The reaction with 3,6-dinonylthieno[3,2-b]-thiophene afforded a corresponding polymer (Polymer 1) with a molecular weight of 17800 in 83% yield under the previously reported conditions (Table 1, Entry 1). 16 Since precipitation of the polymer occurred during the reaction, the reaction was subsequently performed under diluted conditions (Entry 2).…”

Section: Resultsmentioning

confidence: 94%

Direct Arylation Polycondensation of Thienothiophenes with Various Dibromoarylenes

Kumada

Nohara

Kuwabara

et al. 2015

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

CH direct arylation reactions of thieno [3,2-b]thiophenes (TT) with dibromo-substituted aromatic compounds afforded five different kinds of TT-based conjugated polymers, including donoracceptor and dye-containing polymers. Although various thiophene-based polymers have been synthesized previously via polycondensation using direct arylation reactions, our research demonstrates the first direct arylation polycondensation procedure using a TT monomer. The physical properties of the obtained polymers were evaluated by using UVvis absorption spectroscopy and cyclic voltammetry. The dye-containing polymer showed photovoltaic responses in a bulk heterojunction solar cells with a fullerene derivative.Recently, polycondensation via direct CH arylation 14 has become widely recognized as an effective method for the synthesis of π-conjugated polymers as it does not require the preparation of organometallic monomers and hence, does not generate metal-containing by-products. 59 The development of direct arylation polycondensation has allowed use of various monomers such as alkylated thiophenes, 22,23 Expansion of the range of applications of direct arylation polycondensation is important for it to be a reliable method for preparing materials for use in organic optoelectronic devices such as organic photovoltaics (OPV), organic light-emitting diodes (OLED), and organic field-effect transistors (OFET). In this research, we focused on the use of thieno-[3,2-b]thiophenes (TT) as a monomer in direct arylation polycondensation because TT-based polymers have shown excellent performance in OPV and OFET. 24,25 To our best knowledge, there has been no report of direct arylation polycondensation of TT. Direct arylation polycondensation of TT leads to preparation of high-performance polymer in a practical way. Herein, we report synthesis of five different kinds of TT-based polymers including donoracceptor and dye-containing conjugated polymers, via direct arylation polycondensation. The obtained polymers were evaluated in terms of their absorption, electrochemical, and photovoltaic properties. Results and DiscussionThree kinds of TT monomers were tested in direct arylation polycondensation with 2,7-dibromo-9,9-dioctylfluorene which is known to provide high solubility to conjugated polymers (Scheme 1).9,2628 The reaction with 3,6-dinonylthieno[3,2-b]-thiophene afforded a corresponding polymer (Polymer 1) with a molecular weight of 17800 in 83% yield under the previously reported conditions (Table 1, Entry 1). 16 Since precipitation of the polymer occurred during the reaction, the reaction was subsequently performed under diluted conditions (Entry 2). A relatively high molecular weight and yield were obtained at the concentration of 0.15 M. It should be noted that the highmolecular-weight polymer was obtained in 3h with only 2 mol % of a Pd precatalyst without a phosphine ligand which

show abstract

“…In the last decade, an alternative coupling method known as direct arylation has been extensively developed for a variety of building blocks to facilitate the direct polymerization of halogenated (bromo‐, iodo‐) and CH active aromatic monomers, thereby providing a synthetically facile and eco‐friendly alternative to conventional polymerizations . π‐Conjugated polymers synthesized by direct arylation polymerization (DAP) have shown impressive performance in optoelectronics as well .…”

Section: Introductionmentioning

confidence: 99%

Direct arylation polymerization toward efficient synthesis of benzo[1,2‐c:4,5‐c'] dithiophene‐4,8‐dione based donor‐acceptor alternating copolymers for organic optoelectronic applications

Bohra

Chen

Peng

et al. 2018

J. Polym. Sci. Part A: Polym. Chem.

View full text Add to dashboard Cite

Wide‐bandgap π‐conjugated donor‐acceptor (D‐A) alternating copolymers consisting of benzo[1,2‐c:4,5‐c']dithiophene‐4,8‐dione (BDTD) as the electron‐accepting building block have demonstrated outstanding performances in organic bulk heterojunction (BHJ) solar cell devices. But the synthesis of these polymers has been largely limited to conventional polymerization techniques, particularly Stille‐coupling based polycondensations, which often involve tedious preactivation of C‐H bonds using highly flammable reagents such as butyl lithium and highly toxic reagents such as trialkyl tin chlorides. Herein, we report a “greener” synthetic route of direct arylation polymerization to a series of wide bandgap D‐A copolymers with a common acceptor building block of BDTD. The structure–property relationship in these polymers is characterized. We also present the device performances of these polymers in both thin‐film field‐effect transistors and organic BHJ solar cells involving the BDTD‐based polymers as the electron donors and fullerene derivatives as the electron acceptors. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2554–2564

show abstract

Development of Synthetic Method for ^|^pi;-Conjugated Polymers via Direct Arylation Polycondensation

Cited by 23 publications

References 95 publications

Facile synthesis of fluorene-based π-conjugated polymers via sequential bromination/direct arylation polycondensation

Facile synthesis of fluorene-based π-conjugated polymers via sequential bromination/direct arylation polycondensation

Direct Arylation Polycondensation of Thienothiophenes with Various Dibromoarylenes

Direct arylation polymerization toward efficient synthesis of benzo[1,2‐c:4,5‐c'] dithiophene‐4,8‐dione based donor‐acceptor alternating copolymers for organic optoelectronic applications

Contact Info

Product

Resources

About