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1.
Yutaka Nanashima Rena Shibata Ryo Miyakoshi Akihiro Yokoyama Tsutomu Yokozawa 《Journal of polymer science. Part A, Polymer chemistry》2012,50(17):3628-3640
Kumada‐Tamao coupling polymerization of 6‐bromo‐3‐chloromagnesio‐2‐(3‐(2‐methoxyethoxy)propyl)pyridine 1 with a Ni catalyst and Suzuki‐Miyaura coupling polymerization of boronic ester monomer 2 , which has the same substituted pyridine structure, with tBu3PPd(o‐tolyl)Br were investigated for the synthesis of a well‐defined n‐type π‐conjugated polymer. We first carried out a model reaction of 2,5‐dibromopyridine with 0.5 equivalent of phenylmagnesium chloride in the presence of Ni(dppp)Cl2 and then observed exclusive formation of 2,5‐diphenylpyridine, indicating that successive coupling reaction took place via intramolecular transfer of Ni(0) catalyst on the pyridine ring. Then, we examined the Kumada‐Tamao polymerization of 1 and found that it proceeded homogeneously to afford soluble, regioregular head‐to‐tail poly(pyridine‐2,5‐diyl), poly(3‐(2‐(2‐(methoxyethoxy)propyl)pyridine) (PMEPPy). However, the molecular weight distribution of the polymers obtained with several Ni and Pd catalysts was very broad, and the matrix‐assisted laser desorption ionization time‐of‐flight mass spectra showed that the polymer had Br/Br and Br/H end groups, implying that the catalyst‐transfer polymerization is accompanied with disproportionation. Suzuki‐Miyaura polymerization of 2 with tBu3PPd(o‐tolyl)Br also afforded PMEPPy with a broad molecular weight distribution, and the tolyl/tolyl‐ended polymer was a major product, again indicating the occurrence of disproportionation. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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Hai‐Sub Na Yasuhiro Morisaki Yasuhiro Aiki Yoshiki Chujo 《Journal of polymer science. Part A, Polymer chemistry》2007,45(14):2867-2875
Novel π‐conjugated polymers ( 8 – 10 ) were prepared by the palladium‐catalyzed Sonogashira coupling reaction of three kinds of phosphole‐ring‐containing monomers with 2,5‐dihexyloxyl‐1,4‐diethynylbenzene. The obtained polymers ( 8 – 10 ) were regioregulated with the 2,5‐substituted phosphole ring in the polymer main chain and characterized with 1H, 13C, and 31P NMR and FTIR. Polymers 8 – 10 were found to have an extended π‐conjugated system according to the results of UV–vis absorption spectra. In the fluorescence emission spectra of 8 – 10 , moderate emission peaks were observed in the visible blue‐to‐green region. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2867–2875, 2007 相似文献
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Nobukatsu Nemoto Hisamitsu Kameshima Yuta Okano Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2003,41(10):1521-1526
Novel π‐conjugating polymers based on dibenzothiophene were synthesized with a novel dibenzothiophene derivative, 2,8‐bis(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)dibenzothiophene ( 1 ), prepared from dibenzothiophene. The Suzuki coupling polycondensation of 1 with 2,7‐dibromo‐9,9‐dioctylfluorene, 3,6‐dibromo‐9‐octylcarbazole, or 1,4‐dibromo‐2,5‐dioctyloxybenzene afforded the corresponding dibenzothiophene‐based polymers. The measurements of photoluminescence indicated that all these polymers exhibited blue emission in solution. The copolymer containing dibenzothiophene and 9,9‐dioctylfluorene units exhibited higher thermal stability than poly[(9,9‐dioctylfluorene‐2,7‐diyl)], although the quantum yield of copolymer was lower than that of poly[(9,9‐dioctylfluorene‐2,7‐diyl)]. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1521–1526, 2003 相似文献
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Koichiro Mikami Hiroaki Daikuhara Jyunya Kasama Akihiro Yokoyama Tsutomu Yokozawa 《Journal of polymer science. Part A, Polymer chemistry》2011,49(14):3020-3029
Condensation polymerization of 6‐(N‐substituted‐amino)‐2‐naphthoic acid esters ( 1 ) was investigated as an extension of chain‐growth condensation polymerization (CGCP). Methyl 6‐(3,7‐dimethyloctylamino)‐2‐naphthoate ( 1b ) was polymerized at ?10 °C in the presence of phenyl 4‐methylbenzoate ( 2 ) as an initiator and lithium 1,1,1,3,3,3‐hexamethyldisilazide (LiHMDS) as a base. When the feed ratio [ 1a ]0/[ 2 ]0 was 10 or 20, poly(naphthalenecarboxamide) with defined molecular weight and low polydispersity was obtained, together with a small amount of cyclic trimer. However, polymer was precipitated during polymerization under similar conditions in [ 1a ]0/[ 2 ]0 = 34. To increase the solubility of the polymer, monomers 1c and 1d with a tri(ethylene glycol) (TEG) monomethyl ether side chain instead of the 3,7‐dimethyloctyl side chain were synthesized. Polymerization of the methyl ester monomer 1c did not proceed well, affording only oligomer and unreacted 1c , whereas polymerization of the phenyl ester monomer 1d afforded well‐defined poly(naphthalenecarboxamide) together with small amounts of cyclic oligomers in [ 1d ]0/[ 2 ]0 = 10 and 29. The polymerization at high feed ratio ([ 1d ]0/[ 2 ]0 = 32.6) was accompanied with self‐condensation to give polyamide with a lower molecular weight than the calculated value. Such undesirable self‐condensation would result from insufficient deactivation of the electrophilic ester moiety by the electron‐donating resonance effect of the amide anion. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
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Takakazu Yamamoto Masataka Yoshizawa Abla Mahmut Masahiro Abe Shin‐ichi Kuroda Tatsuya Imase Shintaro Sasaki 《Journal of polymer science. Part A, Polymer chemistry》2005,43(24):6223-6232
New π–conjugated polypyrroles such as poly(3‐heptyl‐N‐(t‐butoxycarbonyl)pyrrole‐2,5‐diyl), PPr(3‐Hep; N‐BOC) , and poly(N‐(phenylethynyl)pyrrole‐2,5‐diyl‐alt‐thiophene‐2,5‐diyl), Copoly‐2 , were prepared by organometallic polycondensations using the corresponding 2.5‐dihalopyrroles as the starting materials. Deprotection of the BOC group of PPr(3‐Hep; N‐BOC) proceeded at 185 °C to give poly(3‐heptylpyrrole). XRD (X‐ray diffraction) data of Copoly‐2 indicated that Copoly‐2 assumed a stacked structure in the solid. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6223–6232, 2005 相似文献
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Junpei Miyake Yoshiki Chujo 《Journal of polymer science. Part A, Polymer chemistry》2008,46(18):6035-6040
A novel hybrid‐type chiral binaphthyl‐based polyarylene derivative with polyhedral oligomeric silsesquioxanes (POSS) units 2a was prepared by Suzuki–Miyaura coupling polymerization from a chiral (R)‐6,6′‐dibromo‐2,2′‐diPOSS‐substituted 1,1′‐binaphthyl derivative 1a and p‐biphenylene diboronic acid. As a reference, a binaphthyl‐based polyarylene derivative without POSS unit 2b was also prepared. The obtained polymers were studied with thermogravimetric analysis, optical rotations, circular dichroism (CD), ultraviolet‐visible, and photoluminescence (PL) spectra. Gel permeation chromatography measurements of 2a and 2b showed that their number‐average molecular weights were 13,300 and 16,500, respectively. The thermal stability of POSS‐modified polymer 2a (temperature of 10% weight loss; T10 = 380 °C) was extremely high compared with that of polymer without POSS unit 2b (T10 = 335 °C) due to the siliceous bulky POSS segments on the side chains. The specific optical rotation [α]D was ?66.7° (c 0.06, CHCl3) for 2a and ?62.3° (c 0.06, CHCl3) for 2b . The CD spectra showed that these two polymers had very similar and strong Cotton effects. Film polymer 2a showed almost the same PL spectrum as that in dilute CHCl3 solution, indicating that bulky POSS units strongly suppressed intermolecular aggregation of the π‐conjugated polymer backbone. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6035–6040, 2008 相似文献
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Abdelkrim El‐Ghayoury Albertus P. H. J. Schenning E. W. Meijer 《Journal of polymer science. Part A, Polymer chemistry》2002,40(22):4020-4023
An oligo(p‐phenylene vinylene) that contains terpyridine ligands has been synthesized. Upon addition of metal ions, a π‐conjugated metallo polymer is formed in which the well‐defined character of oligomers and the material properties of polymers are combined. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4020–4023, 2002 相似文献
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Jrg Schappel Kathrin Schmidt Elisabeth Klemm 《Journal of polymer science. Part A, Polymer chemistry》2005,43(16):3574-3587
A Sonogashira polycondensation reaction has been used to synthesize copolymers consisting of alternating oligo(p‐phenyleneethynylene) with a precise block length as an electron‐rich component and 1,4‐bis(2‐phenylene‐2‐cyanovinylene)benzene or 2,6‐bis(2‐pyridinylene‐ethynylene)pyridine as an electron‐poor component. The copolymers differ in the length of the phenyleneethynylene block (trimer or pentamer) and the content of the electron‐poor component. The length of the phenyleneethynylene block has no influence on the maximum wavelength. The electron‐poor cyano‐block component lowers the optical band‐gap energy of the copolymers. The value is equivalent to that of poly(cyano‐phenylenevinylene) (CN‐PPV) (2.3–2.4 eV). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3574–3587, 2005 相似文献
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Masanori Taguchi Ikuyoshi Tomita Yasuhiko Yoshida Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2001,39(4):495-499
An end‐π‐allylnickel macroinitiator ( 3 ) was prepared by the reaction of poly(ethylene glycol) allenyl methyl ether with an excess amount (5 equiv) of [(π‐allyl)NiOCOCF3]2 ( 1 ) in the presence of PPh3 ([PPh3]/[ 1 ] = 1). The resulting macroinitiator was used as an initiator for the polymerization of 1‐phenylethyl isonitrile ( 4a ) to give a block copolymer [poly(ethylene glycol)‐block‐poly( 4a )]. The molecular weight and composition of the block copolymers were controlled by the molecular weight of 3 and the ratio of 4a to 3 . © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 495–499, 2001 相似文献
11.
Liang Liao Ali Cirpan Qinghui Chu Frank E. Karasz Yi Pang 《Journal of polymer science. Part A, Polymer chemistry》2007,45(10):2048-2058
Copolymers containing oligo(phenylene vinylene) (2.5), fluorene, and 4,4‐dihexyldithienosilole (DTS) units were synthesized and characterized. The π‐conjugated monomers were joined with the palladium(0)‐catalyzed Suzuki–Miyaura coupling reaction, thus forming either biphenyl– or phenyl–thiophene linkages. These polymers were photoluminescent, with the fluorescent quantum efficiency between 54 and 63% and with λmax for fluorescence at ~448 nm in tetrahydrofuran. The presence of 5% DTS in the copolymers had little influence on the optical absorption and emission wavelengths. Double‐layer light‐emitting‐diode devices using these polymers as emissive layers had low turn‐on voltages (3.5–4 V) and moderate external quantum efficiencies (0.14–0.30%). The results show that DTS plays a positive role in improving the charge‐injection characteristics of poly(phenylene vinylene) materials. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2048–2058 相似文献
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Yu Tokita Kotaro Sugawara Riho Awayama Yoshihiro Ohta Tsutomu Yokozawa 《Journal of polymer science. Part A, Polymer chemistry》2019,57(24):2498-2504
We investigated the synthesis of polyfluorene with a pinacol boronate (PinB) moiety at one end and with controlled molecular weight by means of Suzuki–Miyaura coupling polymerization of pinacol (7‐bromo‐9,9‐dioctyl‐9H‐fluoren‐2‐yl)boronate ( 1 ) with a palladium(0) precatalyst in the presence of pinacol 4‐trifluoromethylphenylboronate ( 2 ) as a chain terminator and CsF/18‐crown‐6 as a base. When we used AmPhos Pd G2, which has a propensity for intramolecular catalyst transfer on a π‐electron face, polyfluorene with the PinB moiety at one end and PhCF3 (derived from 2 ) at the other end was obtained, and the molecular weight increased in proportion to the feed ratio of [ 1 ]0/[catalyst]0, though the molecular weight distribution was broad. Since the molecular weight also linearly increased with respect to the conversion of 1 until the middle stage of polymerization, the polymerization appears to involve chain‐growth polymerization through intramolecular catalyst transfer from the Pd catalyst inserted into the C? Br bond of 1 . The broad molecular weight distribution might be mainly due to slow initiation and slow termination with 2 , rather than polymer–polymer coupling. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2498–2504 相似文献
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Kensuke Naka Adriana Gelover‐Santiago Takashi Uemura Yoshiki Chujo 《Journal of polymer science. Part A, Polymer chemistry》2003,41(5):708-715
Dithiafulvene oligomers ( 3 ) were prepared by cycloaddition polymerization of aldothioketenes with their alkynethiol tautomers derived from 1,4‐diethynylbenzene ( 2 ) with the addition of 1‐ethynyl‐4‐methylbenzene ( 1 ) as a monofunctionalized compound. Different feed ratios of 2 / 1 were used to control the molecular weights of 3 . The structures of 3 were confirmed by IR and 1H NMR spectroscopies in comparison with those of 2‐(4‐tolylidene)‐4‐tolyl‐1,3‐dithiol ( 4 ) as a model compound, which was obtained by the treatment of lithium 2‐tolylethynethiolate with water in Et2O. The number‐average degree of polymerization (DP) and the number‐average molecular weight were measured by gel permeation chromatographic and 1H NMR analysis. DP increased with an increasing feed ratio of 2 / 1 . The ultraviolet–visible spectra of 3 in diluted acetonitrile showed that the absorption maxima of 3 increased with an increasing DP of 3 . These redshifts are ascribed to an effective expansion of the π‐conjugation system in 3 . The oligomers exhibited a maximum conjugation length of seven repeating units. The redox properties of 3 were examined by cyclic voltammetry. The oxidation half‐peak potentials (Ep/2) of 3 were slightly cathodically shifted with increasing DP. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 708–715, 2003 相似文献
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The influence of the polymer chain structure of soluble polyphenylene (SPP) on the photoluminescence (PL) quenching of fluorene is strongly affected by the 1,2‐phenylene (1,2‐Ph)/1,4‐phenylene (1,4‐Ph) unit molar ratios of SPP, and the amount of 1,4‐Ph units is a major factor for PL quenching. The addition of the fluorenyl group by the formation of carbon–carbon bond at the polymer chain end of SPP is also an important factor for PL quenching of fluorene. Charge (electron) transfer from the fluorenyl end‐group to the main chain of ω‐fluorenyl‐functionalized SPP (FL‐SPP) was very efficient. UV/Vis and PL spectra suggested that this FL‐SPP may be useful for preparing an effective polymer photocell. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Shijie Ren Qiang Fang Feng Yu Dongsheng Bu 《Journal of polymer science. Part A, Polymer chemistry》2005,43(24):6554-6561
Two new π‐conjugated polymers containing 1,3,5‐triazine units in the main chain, Pa and Pb , are reported. Pa and Pb (R = H and ? OCH3, respectively) showed blue photoluminescence emissions with quantum yields of more than 50% in toluene. In the solid state, Pa and Pb showed photoluminescence maximum emission peaks at 479 and 475 nm, respectively. Electrochemically, Pa and Pb showed good stability and reversibility under repeated electrochemical reduction. The polymers had glass‐transition temperatures higher than 90 °C and had 5 wt % loss temperatures higher than 400 °C. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6554–6561, 2005 相似文献
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Kotohiro Nomura Hisao Morimoto Yukio Imanishi Zoubir Ramhani Yves Geerts 《Journal of polymer science. Part A, Polymer chemistry》2001,39(14):2463-2470
High molecular weight trans‐poly(9,9‐di‐n‐octylfluorene‐2,7‐vinylene) was prepared under reduced pressure in the presence of a well‐defined Schrock‐type catalyst, Mo(CHCMe2Ph)(N‐2,6‐Me2C6H3)[OCMe(CF3)2]2, in toluene. The effect of initial monomer concentration was found to be an important factor for preparing high molecular weight polymers with unimodal molecular weight distributions. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2463–2470, 2001 相似文献
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Kenichi Oyaizu Manabu Hoshino Masuhide Ishikawa Takuya Imai Makoto Yuasa 《Journal of polymer science. Part A, Polymer chemistry》2006,44(18):5403-5412
5‐(3‐Thienyl)‐10,15,20‐triethyl‐21H,23H‐porphine (H2(ttep)) was synthesized and characterized. Oxidative polymerization of H2(ttep) gave a novel oligomeric porphyrin linked at the 2,5‐positions of the thienyl group. Electric conductivity of 4 × 10?1 S/cm after I2 doping indicated that the oligomer had a π‐conjugated structure with a delocalization of π electrons over the thienylene backbone. PM3 calculations revealed a low HOCO‐LUCO gap, which was consistent with the relatively high electric conductivity. Regioregular (head‐to‐tail) structure was inferred from spectroscopic and calculational results. The pendant porphyrin groups formed a regular J‐type array along the thienylene backbone, which was indicated by a significant red shift of the Soret band maximum. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5403–5412, 2006 相似文献
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Masataka Nojima Yoshihiro Ohta Tsutomu Yokozawa 《Journal of polymer science. Part A, Polymer chemistry》2014,52(18):2643-2653
Kumada‐Tamao coupling polymerization of 1,4‐dialkoxy‐2‐bromo‐5‐(2‐chloromagnesiovinyl)benzene ( 1 ) and 1,4‐dialkoxy‐2‐(2‐bromovinyl)‐5‐chloromagnesiobenzene ( 2 ) with a Ni catalyst and Suzuki‐Miyaura coupling polymerization of 2‐{2‐[(2,5‐dialkoxy‐4‐iodophenyl)]vinyl}‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane ( 3 ), its bromo counterpart 4 , and 2,5‐dialkoxy‐4‐(2‐bromovinyl)phenylboronic acid ( 5 ) with a Pd initiator were investigated under catalyst‐transfer condensation polymerization conditions for the synthesis of well‐defined poly(p‐phenylenevinylene) (PPV). The Kumada‐Tamao polymerization of vinyl Grignard‐type monomer 1 with Ni(dppp)Cl2 at room temperature did not proceed, whereas aryl Grignard‐type monomer 2 afforded oligomers of low molecular weight. Matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF) mass spectra of the polymer obtained from 2 implied that the Grignard end group reacted with tetrahydrofuran to terminate polymerization. On the other hand, Suzuki‐Miyaura polymerization of vinyl boronic acid ester type monomers 3 and 4 and phenylboronic acid type monomer 5 with a Pd initiator and aqueous KOH at ?20 °C to room temperature yielded the corresponding PPV with high molecular weight within a few minutes. However, the molecular weight distribution was broad, and MALDI‐TOF mass spectra showed the peaks of polymers bearing no initiator unit at the chain end, as well as those of polymers with the initiator unit. These results indicated that intermolecular chain transfer of the Pd catalyst occurred. Dehalogenation and disproportionation of the growing end also took place as side reactions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2643‐2653 相似文献