研究者詳細 - 吉田　嘉晃

論文 - 吉田　嘉晃

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自己修復およびリサイクル可能な光学用樹脂の開発招待有り

吉田　嘉晃

Material stage ( 技術情報協会 ) 24 ( 11 ) 28 - 35 2025年02月

Self-Healing and Recycling Properties of Networked Polydithiourethanes With Reversible Crosslinked Moieties via Hydrogen and Dynamic Covalent Bonding 査読有り国際誌

Yoshida Y., Suenaga R., Sakiyama T., Alem-Marchand H., Meimaroglou D.

Journal of Polymer Science, Part A: Polymer Chemistry 63 ( 16 ) 3301 - 3312 2025年01月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

In this study, eight types of networked Polydithiourethanes (PDTUs) were synthesized with the combinations of various dithioisocyanates, dithiols, and tetrafunctional thiols, and the self-healing behaviors of the networked PDTUs were observed. In particular, the networked PDTUs with an ether structure in the main chain (ET/ET/PE) exhibited a healing efficiency, which was estimated by the ratio of initial and healed toughness values, of up to 77% at 25°C for 24 h. Moreover, the healing efficiency of ET/ET/PE reached almost 100% under the healing conditions at 50°C for 24 h or at 25°C for 48 h. However, after four repetitions of the self-healing operation at 25°C for 24 h, the healing efficiency of ET/ET/PE decreased from 77% to 16%. Herein, the damaged ET/ET/PE was depolymerized at 150°C for 1 h, followed by repolymerization at room temperature, and the damaged ET/ET/PE was chemically recycled as the polymer that exhibited the same toughness and healing efficiency as the initial value. Since PDTUs exhibit a high refractive index and transparency, it is expected to develop applications as a self-healable and chemically recyclable optical resin.

DOI： 10.1002/pol.20250263

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The predictive machine learning model of a hydrated inverse vulcanized copolymer for effective mercury sequestration from wastewater 査読有り国際誌

Ghumman A.S.M., Shamsuddin R., Abbasi A., Ahmad M., Yoshida Y., Sami A., Almohamadi H.

Science of the Total Environment 908 2024年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

Inverse vulcanized polysulfides (IVP) are promising sulfur-enriched copolymers with unconventional properties irresistible for diverse applications like Hg2+ remediation. Nevertheless, due to their inherent hydrophobic nature, these copolymers still offer low Hg2+ uptake capacity. Herein, we reported the synthesis of IVP by reacting molten sulfur with 4-vinyl benzyl chloride, followed by their functionalization using N-methyl D-glucamine (NMDG) to increase the hydration of the developed IVP. The chemical composition and structure of the functionalized IVP were proposed based on FTIR and XPS analysis. The functionalized IVP demonstrated a high mercury adsorption capacity of 608 mg/g (compared to <26 mg/g for common IVP) because of rich sulfur and hydrophilic regions. NMDG functionalized IVP removed 100 % Hg2+ from a low feed concentration (10–50 mg/l). A predictive machine learning model was also developed to predict the amount of mercury removed (%) using GPR, ANN, Decision Tree, and SVM algorithms. Hyperparameter and loss function optimization was also carried out to reduce the prediction error. The optimized GPR algorithm demonstrated high R2 (0.99 (training) and 0.98 (unseen)) and low RMSE (2.74 (training) and 2.53 (unseen)) values indicating its goodness in predicting the amount of mercury removed. The produced functionalized IVP can be regenerated and reused with constant Hg2+ uptake capacity. Sulfur is the waste of the petrochemical industry and is abundantly available, making the functionalized IVP a sustainable and cheap adsorbent that can be produced for high-volume Hg2+ remediation. Environmental implication: This research effectively addresses the removal of the global top-priority neurotoxic pollutant mercury, which is toxic even at low concentrations. We attempted to remove the Hg2+ utilizing an inexpensive adsorbent developed by NMDG functionalized copolymer of molten sulfur and VBC. A predictive machine learning model was also formulated to predict the amount of mercury removal from wastewater with only a 0.05 % error which shows the goodness of the developed model. This work is critical in utilizing this low-cost adsorbent and demonstrates its potential for large-scale industrial application.

DOI： 10.1016/j.scitotenv.2023.168034

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Synthesis, properties, and chemical recyclability of aromatic polyesters using alkylamide diphenolic acid 査読有り国際誌

Omura S., Fukushima S., Sakiyama T., Morita T., Takase M., Yoshida Y., Suzuki T., Mawatari Y.

European Polymer Journal 235 2025年07月

記述言語：英語掲載種別：研究論文（学術雑誌）

This study explores sustainable polymers by synthesizing and characterizing a novel, chemically recyclable, fully aromatic polyester derived from the bio-based compound diphenolic acid (DPA). The new polyester, PDPANHC18, was synthesized via the polycondensation of a DPA monomer modified with a long-chain alkylamide group (DPANHC18) and terephthaloyl chloride. Its properties and chemical recyclability were compared with those of PDPAOC18, an analogous polyester containing a long-chain alkyl ester linkage. The amide linkages in PDPANHC18 significantly enhanced its material properties compared to the ester-linked PDPAOC18. PDPANHC18 exhibited a higher glass transition temperature (Tg) due to strong intermolecular hydrogen bonding between amide groups, which restricted chain mobility and improved thermal stability. Furthermore, PDPANHC18 films demonstrated lower gas permeability, which was attributed to a decrease in free volume and restricted chain mobility caused by hydrogen bonding. Notably, PDPANHC18 exhibited exceptional chemical recyclability via mechanochemical depolymerization under dry, basic conditions. Unlike the ester linkages in PDPAOC18, the amide linkages in PDPANHC18 were resistant to hydrolysis, allowing for the near-quantitative recovery of the DPANHC18 monomer without side-chain degradation. The recovered DPANHC18 monomer mixture could be directly repolymerized into PDPANHC18 without purification, demonstrating a closed-loop recycling process. This research highlights the potential of amide-modified DPA for the development of sustainable, high-performance polymers with efficient chemical recyclability. Strategically modifying bio-based monomers with functional groups such as amides enhances material properties and enables closed-loop recycling, contributing to a circular economy for plastics.

DOI： 10.1016/j.eurpolymj.2025.114048

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易解体およびリサイクルを志向したサスティナブル接着剤の創生招待有り

吉田　嘉晃

明専会報 ( 明専会 ) ( 2025-07 ) 4 - 7 令和７年７・８月号 2025年07月

Aminolysis of five-membered cyclic carbonate catalyzed by guanidines: Solvent effects on the formation of guanidine dimers 査読有り国際誌

Dong W., Sun Y., Yoshida Y., Endo T.

Journal of Molecular Structure 1321 2025年02月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

This paper presents an experimental and computational investigation on the aminolysis reactions of five-membered cyclic carbonate (5CC) catalyzed by mono- or bi-cyclic guanidines in various solvents. For both liquid and solid 5CC substrate employed, higher polar solvent favors the monomeric active guanidine responsible for the catalytic aminolysis reactions. The formation of the dimeric state of the guanidine catalyst, which is seemingly inert to catalytic activity, is prevented by the bulkier substituents connecting to the guanidine moiety. Extensive DFT calculations further confirm that the relative stabilities of dimeric guanidine is depended on both the polarities of the solvents and the bulkiness of the substituents connected to the guanidine moiety, which is consistent with the experimental kinetic results.

DOI： 10.1016/j.molstruc.2024.140299

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ポリジチオウレタンフィルムの光学物性，熱物性，機械物性およびケミカルリサイクル査読有り

吉田　嘉晃, 末永　龍一, 渡邉　ほのか, 遠藤　剛

ネットワークポリマー論文集 ( 合成樹脂工業協会 ) 45 ( 6 ) 270 - 279 2024年11月

担当区分：筆頭著者,　責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）

<p>異なる炭素数のメチレン鎖を有するジイソチオシアネートおよびジチオールをモノマーとして合成した脂肪族ポリジチオウレタン（PDTU）フィルムの光学物性，熱物性および機械物性を評価し，メチレン鎖長が生成ポリマーの物性に与える影響について検討した。さらに，三官能性イソチオシアネートあるいは三官能性チオールを架橋剤として合成したネットワークPDTU フィルムと鎖状ポリマーから成形したフィルムとの物性を比較し，それらのケミカルリサイクル挙動について検討した。</p>

DOI： 10.11364/networkedpolymer.45.6_270

その他リンク： http://id.ndl.go.jp/bib/033829212

Systematic studies on polyacrylates containing side-chain hydrogen bonding units: Significant effects of the pendant functions on thermal behaviors and solubility of polymers 査読有り国際誌

Hirose Y., Yoshida Y., Furusho Y., Tomita I., Endo T.

Journal of Polymer Science 62 ( 10 ) 2116 - 2128 2024年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

The synthesis of polyacrylates containing various pendant hydrogen bonding or non-hydrogen bonding functions and the effects of side-chain functions on their physical properties are described. The polyacrylates possessing urea, urethane, N-substituted urea, or carbonate groups are prepared by the free radical polymerization of acrylate monomers possessing the corresponding functional groups. The presence of stronger hydrogen bonding interactions both in bulk and solutions of a highly polar solvent such as dimethyl sulfoxide (DMSO) is supported by the infrared (IR) spectra, whereas the urethane-based polyacrylate does not exhibit the interaction in the solution. The presence of the stronger hydrogen bonding interactions of the urea unit is discussed by the IR and nuclear magnetic resonance spectra and the density functional theory calculations of the corresponding model compounds. The solubility in organic solvents and the glass transition temperature (Tg) of polymers are also dependent on the structure of the pendant groups. Polar aprotic solvents such as DMSO can only dissolve the urea-based polyacrylate, while the other polymers are soluble in a much wider range of solvents such as tetrahydrofuran. The urea-based polyacrylate shows the highest Tg among the polymers studied owing to the presence of plural hydrogen bonding sites in the urea groups.

DOI： 10.1002/pol.20230893

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Synthesis of water-soluble tetrafunctional urethane acrylate bearing a pentaerythritol core and its radical polymerization behaviors in an aqueous solution 査読有り

Okamoto S., Watanabe Y., Yoshida Y., Endo T.

Polymer 286 2023年11月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

A novel water-soluble tetrafunctional urethane acrylate (TUA) was successfully synthesized by addition reaction of pentaerythritol to 2-isocyanatoethyl acrylate. TUA efficiently underwent radical polymerization and its copolymerization with monofunctional acrylate monomers exhibiting hydrophilicity in an ethanol aqueous solution, affording corresponding networked polymers in high yields. Notably, TUA exhibited much lower volume shrinkage during the radical polymerization compared to a comparative pentaerythritol core based tetrafunctional acrylate containing no urethane bonds. The thermal decomposition temperature of the networked homopolymer, synthesized from TUA, was much higher than those of the linear polymers, synthesized from monofunctional urethane acrylate monomers. TUA is expected to be applied to the development of environmentally sustainable polymer materials.

DOI： 10.1016/j.polymer.2023.126402

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Bivalent monomer bearing styryl and five-membered cyclic dithiocarbonate moieties for orthogonal radical and cationic ring-opening polymerizations 査読有り国際誌

Yoshida Y., Krishnamurthy S., Asakura N., Endo T.

Journal of Polymer Science 61 ( 15 ) 1651 - 1659 2023年08月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

We synthesized a novel bivalent monomer 1 bearing 4-vinylbenzyl group and five-membered cyclic dithiocarbonate. This monomer 1 was polymerized orthogonally by free radical polymerization to afford polystyrene 1a bearing a five-membered cyclic dithiocarbonate moiety in the side chain. On the other hand, cationic ring-opening polymerization of five-membered cyclic dithiocarbonate in the monomer 1 successfully proceeded, resulting in a narrow molecular weight distribution of polydithiocarbonate 1b bearing a 4-vinylbenzyl group in the side chain. Furthermore, post-polymerizations of 1a and 1b maintaining the polymerizable functionality were carried out respectively by suitable polymerization methods. The five-membered cyclic dithiocarbonate of 1a underwent cationic ring-opening polymerization with a high molar ratio of methyl trifluoromethanesulfonate at a high temperature compared to the case of monomer 1, whereas radical polymerization of the 4-vinylbenzyl group of 1b successfully proceeded under the almost same conditions as the case of monomer 1. These post-polymerizations achieved the synthesis of corresponding networked polymers 2a and 2b.

DOI： 10.1002/pol.20230173

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Stereospecific radical polymerization of methacrylate bearing oxazolidone structure and improvement of glass transition temperature of urethane methacrylate copolymers 査読有り国際誌

Yoshinaga Y., Yoshida Y.

Journal of Polymer Science 2023年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

We synthesized the novel methacrylate monomer bearing an oxazolidone structure (M1) and performed radical polymerization of M1 by traditional procedures. The glass transition temperature (Tg) of the obtained polymer (P1) was a significantly high value compared to that of poly(methyl methacrylate) and typical poly(urethane methacrylate)s. The copolymers of M1 and monofunctional urethane methacrylate derived from 2-hydroxyethyl methacrylate and phenyl isocyanate (M2) exhibited a linear rise of the Tg values depending on the composition ratio of M1. The NMR analysis and the estimation of monomer reactivity ratio and Q–e values suggested that the improvement of glass transition temperature resulted from a stereoregularity, meaning a syndiotacticity of the copolymers improved with increasing the composition ratio of M1. Furthermore, the thermal curing reaction of M1 or M2 with bifunctional urethane acrylate successfully proceeded, then the Tg value of the cured product from M1 was much higher than that from M2.

DOI： 10.1002/pol.20230210

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Special structures and thermal stabilities of polyurethanes derived from diol and triol having oxazolidone moieties 査読有り国際誌

Yoshida Y., Yoshinaga Y., Endo T.

Journal of Polymer Science 2023年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

We synthesized regular polyurethanes from the diol having oxazolidone structure (Diol-1) and the aliphatic diisocyanate by typical polyaddition. The results of the structural analysis suggested that the polyurethane having a cyclic urethane structure such as oxazolidone formed a rod-like structure, although the control polyurethane having a chain urethane structure formed a linear structure. The polyaddition of Diol-1 and aliphatic diisocyanate with triol having oxazolidone structure (Triol-1) as a crosslinker also proceeded successfully to achieve corresponding polyurethanes. However, the polyurethanes containing a molar ratio of Triol-1 less than or equal 50% were soluble in high polar organic solvents nevertheless those polyurethanes contained some trifunctional units in the polymer chain. On the other hand, the polyurethanes containing a molar ratio of Triol-1 more than 50% were insoluble in any organic solvents. We hypothesized that the soluble polyurethanes containing Triol-1 formed multi-branched structure and the insoluble polyurethanes formed cross-linking structure. Such structures of polymer chain affected significantly to the thermal properties of the obtained polyurethanes.

DOI： 10.1002/pol.20230187

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Cationic ring-opening polymerization of a five membered cyclic dithiocarbonate having a tertiary amine moiety 査読有り国際誌

Krishnamurthy S., Yoshida Y., Endo T.

Polymer Chemistry 13 ( 2 ) 267 - 274 2022年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

In this work, a facile route for the cationic ring-opening polymerization (CROP) of a cyclic dithiocarbonate derived from N,N-dibenzyl glycidylamine (DBGA) and carbon disulfide has been developed. The cyclic dithiocarbonate monomer, 5-((dibenzylamino)methyl)-1,3-oxathiolane-2-thione (1), can be obtained economically and easily in three steps from commercially available N,N-dibenzylamine. The cationic polymerization of 5-((dibenzylamino)methyl)-1,3-oxathiolane-2-thione (1) was achieved using methyl triflate or ethyl triflate as an initiator. The polymerization proceeded smoothly in chlorobenzene with high monomer conversion (>90%). The polymers exhibited a high molar mass with narrow dispersity. The structure of the polymers was confirmed by NMR and IR analyses. Investigation of the mechanism of this polymerization by NMR studies on the stoichiometric reaction of 1 with MeOTf indicates the higher reactivity of sulfur than that of nitrogen for the initiator (methyl cation, S > N). A strong possibility of formation of a transient aziridinium ion by neighboring group participation of the tertiary amine moiety is also seen. Finally evidence from DFT calculation also clarifies the presence of more negative charge on the sulfur atom of the thiocarbonyl group compared to nitrogen.

DOI： 10.1039/d1py01230d

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Rate Control of Helix Oscillation of Poly(arylacetylene)s Achieved by Design of Side-Group Structures 査読有り

Mawatari Y., Oouchi M., Yoshida Y., Hiraoki T., Tabata M.

Macromolecules 54 ( 16 ) 7400 - 7408 2021年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

Poly(2-ethynylnaphthalene)s with different alkylester moieties at the 6-position (PNRs) were synthesized to observe the first helix oscillation (HELIOS) of helical poly(arylacetylene)s, a transition between stretched and contracted helices in solution unique to helical structures. Variable-temperature (VT) 1H NMR spectra of PNRs were measured to analyze the microstructures of the two helices. The size of the aromatic ring and the structures of the alkyl chain in the side group on the PNRs strongly affected the rate of the HELIOS mode. The temperature dependencies of the relative ratio of populations between stretched and contracted helices were estimated. The differences in microstructures between stretched and contracted helices were also discussed based on the results of molecular mechanics calculations and 1H-13C heteronuclear single-quantum correlation spectroscopy (1H-13C HSQC). Consequently, we successfully changed the rate of HELIOS of PNRs and obtained detailed information on the molecular conformation of the stretched and contracted helices.

DOI： 10.1021/acs.macromol.1c00790

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Synthesis of multifunctional 4-hydroxymethyl 2-oxazolidinones from glycidyl carbamate derivatives catalyzed by bicyclic guanidine 査読有り

Yoshida Y., Endo T.

Tetrahedron Letters 72 2021年05月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

4-Hydroxymethyl 2-oxazolidinones have been successfully synthesized under mild conditions by the intramolecular cyclization of glycidyl carbamate derivatives with a bicyclic guanidine as the efficient catalyst. This reaction system, which is also applicable to the multifunctional compounds, can provide bi- and tri-functional alcohols having oxazolidinone moieties.

DOI： 10.1016/j.tetlet.2021.153086

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Synthesis of poly(hydroxyurethane) from 5-membered cyclic carbonate under mild conditions in the presence of bicyclic guanidine and their reaction process 査読有り

Dong W., Yoshida Y., Endo T.

Journal of Polymer Science 59 ( 6 ) 502 - 509 2021年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

A series of amines are applied as catalysts in the aminolysis reactions of five-membered cyclic carbonate (5CC). Kinetic results display that TBD, which has a guanidine structure, exhibits the best catalytic efficacy and the reaction rate constant is about 100 times higher than the blank system without catalyst. The reaction medium, NMP is found to be as both solvent and promoter in the aminolysis of 5CC. Finally, with TBD and NMP as catalyst and solvent, respectively, the polymerization of bis-functional 5CC (B5CC) and 1, 6-diaminohexane can proceed almost 100% at room temperature in less than 4 h to obtain poly(hydroxyurethane)s (PHUs) with moderate molecular weight.

DOI： 10.1002/pol.20200825

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Synthesis and Thermal Properties of Polyamic Acids and Its Six-Membered Cyclic Polyimides from Ethylenediaminetetraacetic Acid 査読有り

CHENNAPURAM Madhu, YOSHIDA Yoshiaki, ENDO Takeshi

ネットワークポリマー論文集 ( 合成樹脂工業協会 ) 42 ( 3 ) 90 - 97 2021年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

<p>This article represents the synthesis and characterization of polyamic acids and polyimides derived from several bifunctional amines with ethylenediaminetetraacetic acid (EDTA) anhydride using polyaddition followed by chemical/thermal imidization methods. The structural and thermal properties of the obtained polyamic acids and their six-membered cyclic polyimides were determined in detail by using FT-IR, TGA, and DSC analysis. Additionally, this method was also extended to synthesis of networked polyamic acid and polyimide using trifunctional amine and EDTA anhydride.</p>

DOI： 10.11364/networkedpolymer.42.3_90

その他リンク： https://ci.nii.ac.jp/naid/130008073107

Curing behavior and properties of epoxy monomers with ethylenediaminetetraacetic dianhydride 査読有り

Chennapuram M., Yoshida Y., Endo T.

Journal of Applied Polymer Science 2021年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

Ethylenediaminetetraacetic acid dianhydride (EDTADA) is a six-membered cyclic anhydride that contains two tertiary amino groups in the structure. In this work, we have demonstrated that a curing reaction of diglycidyl ether of bisphenol A (DGEBA) and EDTADA proceeded efficiently without any accelerant such as tertiary amine and imidazole. This result proves that EDTADA can act as a self-sustaining accelerant for the curing reaction of the epoxy monomers. On the other hand, the curing reaction of glycidol with EDTADA proceed successfully via an initiation step owing to the esterification of primary alcohol and anhydride moieties. In this case, we demonstrate that EDTADA also works as an amine catalyst for esterification. Moreover, we have studied the adhesive properties of two types of epoxy resin derived from DGEBA and glycidol with EDTADA.

DOI： 10.1002/app.51626

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Phosgene-free and Chemoselective Synthesis of Novel Polyureas from Activated l -Lysine with Diphenyl Carbonate 査読有り

Yakeya D., Yoshida Y., Endo T.

Macromolecules 53 ( 16 ) 6809 - 6815 2020年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 American Chemical Society. Nα,Nϵ-(Phenoxycarbonyl)-l-lysine methyl ester 1a can be expected to behave as a difunctional blocked diisocyanate monomer derived from l-lysine with diphenyl carbonate. In this report, we examined a reaction of the obtained compound 1a and 1 equiv of n-butylamine as a model reaction to find that the Nα position of compound 1a reacted selectively with an amine. This means that the reactivity of Nα- and Nϵ-phenoxycarbonyl groups is different because the Nα-phenoxycarbonyl moiety has an adjacent ester group. From this result, synthesis of the corresponding polyureas was evaluated by a stepwise reaction of compound 1a with various diamines. The structure analysis and the study of thermal properties of the synthesized polyureas suggested that the carbodiimide moieties were partly constructed in the main chain because of the dehydration triggered by heat treatment of the polyureas.

DOI： 10.1021/acs.macromol.0c01039

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Synthesis and fundamental properties of methacrylate polymer containing five-membered cyclic trithiocarbonate group 査読有り

Nishi M., Komeda M., Aoyagi N., Yoshida Y., Endo T.

Journal of Polymer Science 58 ( 15 ) 2126 - 2133 2020年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2020 Wiley Periodicals LLC. 4-(1,3-Dithia-2-thioxocyclopenthyl)methacrylate (TCMA), containing the five-membered trithiocarbonate moiety, was prepared from glycidyl methacrylate (GMA) through 2,3-epithiopropyl methacrylate (ETMA). At first step, GMA was converted to ETMA by the reaction using thiourea. At second step, ETMA was reacted efficiently with carbon disulfide in the presence of a catalytic amount of 1,2-dimethyltetrahydropyrimidine to give TCMA. The polymerization of TCMA proceeded under standard radical conditions to give the polymeric TCMA in 94% yield. The copolymerizations of TCMA with ethyl acrylate (EA) or acrylonitrile (AN) were conducted by changing the feed molar ratios of the monomers, in which the corresponding copolymers were obtained in over 83% yields. In addition, the obtained polymers showed the high values of refractive index over ca. 1.6 due to the presence of the cyclic trithiocarbonate structure.

DOI： 10.1002/pol.20200201

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ヘテロクムレン類を原料とした高分子材料の開発招待有り

吉田　嘉晃

化学と工業 ( 日本化学会 ) 73 ( 4 ) 340 - 341 2020年04月

Synthesis of polymethacrylate-bearing benzocyclobutene structure and extension to networked polymer based on thermal isomerization 査読有り

Komeda M., Nagayama S., Yoshida Y., Endo T.

Journal of Polymer Science, Part A: Polymer Chemistry 57 ( 21 ) 2175 - 2180 2019年11月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Wiley Periodicals, Inc. 1-Benzocyclobutenyl methacrylate-bearing methacrylate (BCBMA) backbone has been synthesized, and radical polymerization of the monomer was performed by utilizing 2, 2′-azobisisobutyronitrile (AIBN) as initiator to result poly-BCBMA. Differential scanning calorimetry (DSC) measurement of the derived poly-BCBMA revealed the lowering of thermal isomerization temperature from that of nonsubstituted benzocyclobutene. The thermal decomposition temperature of BCBMA before and after thermal treatment was confirmed by thermogravimetric analysis (TGA). The results of the TGA observation did not show significant difference in both 5% and 10% weight loss temperature (Td5 and Td10). This result suggests that the thermal conversion of the poly-BCBMA to the networked polymer take place without thermal decomposition of the main chain based on the methacrylate framework. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2175–2180.

DOI： 10.1002/pola.29495

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Synthesis and decrosslinking of networked polymers having zwitterion structure consisted by cyclic amidine and isothiocyanate 査読有り

Yamauchi A., Yoshida Y., Endo T.

Journal of Polymer Science, Part A: Polymer Chemistry 57 ( 20 ) 2131 - 2137 2019年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Wiley Periodicals, Inc. We have already found that the polymers, which are obtained by the polymerization of 4-vinylphenyl isothoiocyanate after the zwitterion formation with cyclic amidines, are networked through the ionic interaction among the zwitterions becoming insoluble to various solvents. We report here on the results of the reaction of nucleophilic reagents such as amines and alcohols with the zwitterionic adduct to investigate about the decrosslinking through the resolution of ionic interactions. In the model reactions of amines and alcohols with the zwitterion compounds, which were consisted of the phenyl isothiocyanate and cyclic amidines, the reaction of nucleophilic reagents and zwitterionic adducts having methyl group at the 2-position of the amidine proceed quantitatively. Based on the model reaction, such nucleophilic addition was applicable to decrosslinking reaction of the networked polymers containing the zwitterion structure in the side-chain. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2131–2137.

DOI： 10.1002/pola.29485

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Reprocessable Aliphatic Polydithiourethanes Based on the Reversible Addition Reaction of Diisothiocyanates and Dithiols 査読有り

Yoshida Y., Ohnaka K., Endo T.

Macromolecules 52 ( 16 ) 6080 - 6087 2019年08月

担当区分：筆頭著者記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

Copyright © 2019 American Chemical Society. Aliphatic polydithiourethanes (PDTUs) were successfully synthesized from diisothiocyanates and dithiols having different values of the carbon atom number. The thermal properties and hydrogen-bonding behavior of PDTUs were studied in detail by using differential scanning calorimetry, thermal gravimetric analysis, temperature dependence nuclear magnetic resonance, Fourier transform infrared-attenuated total reflection, and density functional theory and semiempirical molecular orbital methods. In this work, we demonstrated that the thermal decomposition of PDTUs happened from the cleavage of the C-S bond of the dithiocarbamate moiety in the main chain and also that the active isothiocyanate and thiol groups were reprepared in the terminal of the decomposed polymer (i.e., oligomer). Furthermore, we found that the thermal depolymerization of PDTUs and the repolymerization of dithiourethane oligomers at room temperature proceeded repeatedly a few times.

DOI： 10.1021/acs.macromol.9b00350

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Synthesis and physical properties of poly(urethane)s using vicinal diols derived from acrylate and styrene monomers 査読有り

Akbulut H., Yoshida Y., Yamada S., Endo T.

Journal of Polymer Science, Part A: Polymer Chemistry 57 ( 7 ) 799 - 805 2019年04月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 Wiley Periodicals, Inc. We describe the utilization of four kinds of diol derivatives, representing structural similarity to the well-known and commercially available vinyl monomers such as acrylate, acrylamide, styrene, and N-substituted maleimide. The vinyl monomers are readily converted by dihydroxylation reaction to afford the vicinal diol. The synthesis of poly(urethane)s was performed by the reaction of the vicinal diol with two model diisocyanates, including methylene diphenyl isocyanate (MDI) and hexamethylene diisocyanate (HDI) in the presence of dibutyltin dilaurate to form a series of poly(urethane)s, and the effect of vicinal diol containing a side chain inherited from vinyl monomers on their thermal and mechanical properties was investigated using thermogravimetric analysis, differential scanning calorimetry, and tensile test. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 799–805.

DOI： 10.1002/pola.29328

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Methoxy-group control of helical pitch in stereoregular poly(2-ethynylmethoxynaphthalene) prepared by rhodium complex catalyst 査読有り

Mawatari Y., Yoshida Y., Huang K., Tabata M.

Polymers 11 ( 1 ) 2019年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 by the authors. The position of the methoxy group in a poly(n-methoxy-2-ethynylnaphthalene) (PnMeO2EN) was found to control the helical pitch of the π-conjugated polymer in the solid state. These PnMeO2ENs were stereoregularly synthesized using an Rh-complex catalyst in ethanol or toluene as the solvent. The helical structure in the solid phase was confirmed by conventional analytical methods, namely diffuse reflective ultraviolet-visible light (UV-Vis) and Raman spectroscopies, X-ray diffraction, and 13 C cross-polarization magic angle spinning NMR spectroscopy, together with molecular mechanics calculations, because the as obtained polymers were insoluble in common solvents. The color of poly(6-methoxy-2-ethynylnaphthalene) (P6MeO2EN) (yellow or red) depended on the polymerization solvent, whereas no such dependency was observed for the yellow-colored P7MeO2EN and P8MeO2EN. The helical structures energetically optimized by molecular mechanics indicate that the red- and yellow-colored P6MeO2ENs form contracted and stretched helices, respectively. Due to the relatively unconstrained rotations of the 6-methoxynaphthyl moieties, the methoxy groups in P6MeO2EN are less sterically hindered along the helical axis. On the contrary, P7MeO2EN and P8MeO2EN have stretched helices due to the considerable steric hindrance imparted by their methoxy groups. The thermal cis-to-trans isomerization of P6MeO2EN in the contracted-helix form required a somewhat higher temperature than that of the stretched helix.

DOI： 10.3390/polym11010094

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Proposed mechanism for the high-yield polymerization of oxyethyl propiolates with Rh complex catalyst using the density functional theory method 査読有り

Yoshida Y., Mawatari Y., Tabata M.

Polymers 11 ( 1 ) 2019年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2019 by the authors. In this study, poly(oxyethyl propiolate)s (POP)s featuring various oxyethylene derivatives are synthesized using a [Rh(norbornadiene)Cl] 2 catalyst. In particular, POPs featuring the normal oxyethylene chain in the side-chain exhibit excellent yields and high molecular weights in methanol and N,N-dimethylformamide at 40 °C, compared with poly(n-alkyl propiolate)s (PnAP)s. The high reactivity of the oxyethyl propiolate (OP) monomers is clarified by considering the time dependences of the polymerization yields of OPs and alkyl propiolates (Aps). Furthermore, the monomer structure and intermediate conformation of the Rh complex are optimized using Density Function theory (DFT) methods (B3LYP/6-31G ** and B3LYP/LANL2DZ) and a polymerization mechanism is proposed.

DOI： 10.3390/polym11010093

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最近のラジカル開環重合の進歩とネットワークポリマーへの展開招待有り査読有り

遠藤　剛，吉田　嘉晃

ネットワークポリマー論文集 ( 合成樹脂工業協会 ) 40 ( 1 ) 45 - 54 2019年01月

Synthesis of polydithiourethanes and their thermal, optical, and mechanical properties originated from monomers structure 査読有り

Yoshida Y., Endo T.

Journal of Polymer Science, Part A: Polymer Chemistry 56 ( 19 ) 2255 - 2262 2018年10月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Wiley Periodicals, Inc. Polyaddition of various diisothiocyanates and dithiols was achieved with triethylamine in dimethylformamide at 25 °C for 12 h under nitrogen, and then the corresponding polydithiourethanes (PDTUs) were obtained with high yield and molecular weight without depending on the monomer structures, although the dithiol monomer of the low nucleophilicity was unsuitable for polyaddition in this system. The chemical and physical properties of the obtained PDTUs such as solvent solubility, glass transition temperature, thermal stability, transparency, refractive index, and tensile strength, were analyzed in detail by gel permeation chromatography, nuclear magnetic resonance, Fourier transform infrared–attenuated total reflection, ultraviolet–visible, differential scanning calorimetry, thermogravimetric analysis, and tensile testing measurements. These results proved that PDTUs and their cast films having the aliphatic diisothiocyanate and dithiol moieties exhibited excellent chemical and physical properties compared to that of the aromatic PDTUs. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2255–2262.

DOI： 10.1002/pola.29198

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Selective formation of a zwitterion adduct and bicarbonate salt in the efficient CO<inf>2</inf> fixation by N-benzyl cyclic guanidine under dry and wet conditions 査読有り

Yoshida Y., Aoyagi N., Endo T.

Beilstein Journal of Organic Chemistry 14 2204 - 2211 2018年08月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2018 Yoshida et al. The efficient CO2 fixation by N-benzyl cyclic guanidine 1 was achieved by bubbling dry CO2 through CH3CN at 25 °C for 2 h. In addition, the zwitterion adduct 2 and bicarbonate salt 3 were selectively prepared from 1 under dry (in anhydrous CH3CN) and wet (in CH3CN containing an equimolar amount of water for 1) conditions, respectively. Both compounds 2 and 3 were isolated as white solids and their structures were characterized in detail by elemental analysis, FTIR-ATR, solid-state NMR, TGA, and DFT calculation. These analytical results obviously revealed the formation of a zwitterion adduct and bicarbonate salt from N-benzyl cyclic guanidine and CO2. Especially, the zwitterion adduct of the monocyclic guanidine derivative and CO2 was isolated and characterized for the first time.

DOI： 10.3762/bjoc.14.194

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Dependence of color change of vinylethylene carbonate copolymers having N-substituted maleimides on chemical structure by acid-base switching in solution and solid state 査読有り

Yoshida Y., Endo T.

Reactive and Functional Polymers 120 139 - 146 2017年11月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 The copolymers of vinylethylene carbonate (VEC) and N-substituted maleimide (NMI) having various N-substituents were synthesized by radical polymerization. The color of P(VEC/NMI)s changed from colorless to red reversibly based on the acid-base switching in solution and solid state. Furthermore, the color depth of P(VEC/NMI) solution and powder changed systematically depending on the electric effect of N-substituents. However, the copolymers of styrene and NMIs barely changed under the same conditions. These color change and depth behaviors of NMI copolymers were analyzed in detail by UV–vis and IR spectra, and the results were also supported by the density functional theory (DFT) calculation for the model compound of maleimide tautomers. Additionally, the powder color of P(VEC/NMI)s changed reversibly before and after exposure to cigarette smoke and vinegar.

DOI： 10.1016/j.reactfunctpolym.2017.10.001

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Synthesis and solid-state properties of crosslinked alternating copolymers of phenyl vinylethylene carbonate and N-substituted maleimides 査読有り

Yoshida Y., Endo T.

Journal of Applied Polymer Science 134 ( 35 ) 2017年09月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 Wiley Periodicals, Inc. The copolymers of phenyl vinylethylene carbonate (PVEC) and N-phenylmaleimide were prepared with various monomer feeds by using a radical initiator. These copolymers were crosslinked by aminolysis between hexamethylenediamine (HMDA) and cyclic carbonate moiety in the side-chain to obtain the networked polymers having the hydroxyurethane structure. Furthermore, the crosslinked copolymers having the polar cyclic carbonate in the side-chain were synthesized from PVEC and several bifunctional maleimides, and their double networked polymers were prepared with HMDA. These copolymers and networked polymers exhibited color changes depending on their structures based on the acid–base switching in the solid-state. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45247.

DOI： 10.1002/app.45247

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Strictly Alternating Sequences When Copolymerizing Racemic and Chiral Acetylene Monomers with an Organo-Rhodium Catalyst 査読有り

Yoshida Y., Mawatari Y., Sasaki T., Hiraoki T., Wagner M., Müllen K., Tabata M.

Macromolecules 50 ( 4 ) 1291 - 1301 2017年02月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 American Chemical Society. A racemic mixture and two chiral monomers of 2-methyl-1-butyl propiolate, i.e., rac1, R1, and S1, were stereoregularly polymerized with a catalyst, [Rh(norbornadiene)Cl]2, in methanol at 40 °C to obtain the corresponding helical racemic and two chiral polymers, Prac1, PR1, and PS1, and a copolymer, Pco. The 1H and 13C NMR spectra of the racemic and chiral polymers differed, although the NMR spectra of their monomers were the same. The structures of the Pco copolymers with different chiral monomer ratios were analyzed using 1D and 2D NMR, optical rotation, circular dichroism (CD), UV-vis, and computational methods to elucidate the stereochemical effect of the chiral monomers together with the polymerization mechanism. The temperature dependence of 1H and 13C NMR spectra in line shape and intensity indicated that the helical main chain undergoes restricted rotation around the ester methylene bonds −O-CH2- through a three-site jump exchange called an accordion-like helix oscillation (HELIOS). The energetically preferred structures of the helical-sense polymers PR1 or PS1 were simulated using the MMFF94 program. The dependence of the NMR spectral line shapes, optical rotations, and calculated structures on the monomer feed clearly indicated that the copolymers alternatively incorporate R1 and S1 to generate one-handed helical-sense chains. Based on these results, a polymerization mechanism is proposed, explaining a strictly alternating copolymerization that yields helical chains.

DOI： 10.1021/acs.macromol.6b02508

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混合気体から炭酸ガスの高選択的分離を目指した一置換ポリアセチレン膜の開発招待有り

吉田　嘉晃, 馬渡　康輝, 田畑　昌祥

化学工業 ( 化学工業社 ) 68 ( 1 ) 58 - 66 2017年01月

Substituent dependence of imidazoline derivatives on the capture and release system of carbon dioxide 査読有り

Yoshida Y., Aoyagi N., Endo T.

New Journal of Chemistry 41 ( 23 ) 14390 - 14396 2017年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. The reversible capture-release behaviors of CO2 by imidazoline derivatives bearing several 2-substituents were investigated under dry conditions containing a very small amount of water. The imidazoline having a cyclic guanidine moiety only captured CO2 quantitatively, and then the cyclic guanidine derivative gave the guanidinium bicarbonate by CO2 fixation together with a slight amount of water. In contrast, the imidazolines bearing n-butylthiol and n-pentyl groups never captured CO2 even with the addition of an equimolar amount of water. Furthermore, the binding structure between CO2 and the cyclic guanidine derivative was studied in detail by elemental analysis, FTIR-ATR, solid-state NMR, TGA, and DFT calculations in order to predict the CO2 capture-release mechanisms depending on the imidazoline structure.

DOI： 10.1039/c7nj03133e

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Color change of alternating copolymers with phenyl vinylethylene carbonate and N-phenylmaleimide in a solution and in the solid-state, depending on their structure 査読有り

Yoshida Y., Endo T.

RSC Advances 7 ( 15 ) 9373 - 9380 2017年01月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© The Royal Society of Chemistry. Radical copolymerization, with various monomer feeds of phenyl vinylethylene carbonate (PVEC) and N-phenylmaleimide (PMI), successfully proceeded through selective vinyl and alternating polymerization to obtain copolymers having the maleimide unit in the main-chain and the five-membered cyclic carbonate group in the side-chain. The structure of these copolymers was analyzed in detail using NMR, IR, and UV-Vis methods. The UV-Vis spectra supported the tautomerization of the maleimide unit based on the solvent effect and the alternating and/or homo sequence constructed depending on the monomer feeds. Furthermore, these copolymers exhibited sensitive and reversible color changes based on acid-base switching not only in solution but also in the solid-state. In particular, the color change in the solid-state occurred immediately after exposure to the amine vapor.

DOI： 10.1039/c6ra28446a

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Synthesis and thermal properties of vinyl copolymers with phenyl vinylethylene carbonate and: N -substituted maleimides undergoing color change with acid-base switching 査読有り

Yoshida Y., Endo T.

Polymer Chemistry 7 ( 44 ) 6770 - 6778 2016年11月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 The Royal Society of Chemistry. The radical copolymerization of phenyl vinylethylene carbonate (PVEC) with various vinyl and cyclic monomers successfully proceeded through selective vinyl polymerization. In particular, compared with that of the other vinyl and cyclic comonomers, the copolymerization with the N-substituted maleimides (NMI) exhibited high yield and molecular weight without dependence on the N-substituents, due to construction of a charge-transfer complex between PVEC (electron-donor) and NMI monomers (electron-acceptors). IR and UV-vis spectra of these copolymers suggested that the alternating polymerization proceeded between PVEC and NMI monomers, and also indicated that the malemide moiety formed an enolate tautomer in the presence of sufficiently strong basic reagents. The solution of these copolymers was red in color in basic solvents due to the formation of the enolate tautomer, and the solution color changed with a high sensitivity to acid-base switching. These copolymers also exhibited high thermal stability resulting from the maleimide moiety contained within the main-chain.

DOI： 10.1039/c6py01510g

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Mutual Conversion between Stretched and Contracted Helices and its External Stimuli Induced Drastic Colors and Geometrical Structures Changes of Substituted Polyacetylenes Prepared with an Organo-Rhodium Catalyst 査読有り国際誌

Masayoshi Tabata, Yasuteru Mawatari, Yoshiaki Yoshida, and Takahiro Sasaki

Advances in Science and Technology ( Trans Tech Publications ) 97 18 - 23 2016年10月

Radical polymerization behavior and thermal properties of vinyl ethylene carbonate derivatives bearing aromatic moieties 査読有り

Yoshida Y., Endo T.

Polymer 102 167 - 175 2016年10月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2016 Elsevier Ltd Vinyl ethylene carbonate (VEC) derivatives bearing aromatic moieties were prepared by the catalyzed addition of carbon dioxide (CO2) to butadiene monoxide (BMO) derivatives. The radical polymerization of the VEC monomers was carried out in bulk and solution by using a radical initiator, and those produced polymers were analyzed in detail by IR, NMR, and MALDI-TOF mass methods. These results indicated that radical polymerization of VEC derivatives proceeded through the selective vinyl fashion without depending on the substituents and solvents. Furthermore, the chain transfer reaction occurred easily in NMP and the produced polymer had the NMP moiety in the polymer terminal. The radical polymerization of the bifunctional monomer also proceeded through the vinyl fashion together with the chain transfer reaction in NMP and produced the gelation polymer. Electron-withdrawing of the substituents influenced the thermal property of the produced polymer and bifunctional polymer also obtained the high thermal stability than monofunctional polymer. In this report, the polymerization behavior and property of VEC derivatives bearing aromatic groups was summarized systematically.

DOI： 10.1016/j.polymer.2016.09.002

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Remarkably stretched cis-transoid helices generated in solid phase and solution of poly(carbazole acetylene) prepared using an organorhodium catalyst in Toluene 査読有り

Sasaki T., Yoshida Y., Mawatari Y., Tabata M.

Macromolecules 48 ( 4 ) 889 - 897 2015年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2015 American Chemical Society. A helical π-conjugated poly(N-isobutyl-3-carbazole acetylene), P(iBCzA) was stereoregularly prepared using an [Rh(norbornadine)Cl]2-triethylamine catalyst in toluene at 25 °C to determine the detailed geometrical and spatial structures in a tetrahydrofuran (THF) solution and the solid phase. P(iBCzA), which has a bright orange color, was obtained in a yield of 90%. The 2D NMR spectrum of P(iBCzA) in THF-d8 at 50 °C indicated that an extraordinarily extended helix was produced. The WAXS pattern of P(iBCzA) showed the formation of a tetragonal crystal packed with a remarkably stretched cis-transoid (RESTCT) helix similar to that observed in the solution state. This RESTCT helix was confirmed not to be an energetically stable but a metastable structure using MMFF94 program. The solid phase UV-vis spectrum of P(iBCzA) showed the formation of a radical cation called a polaron because of the very large red shifts compared to that observed in solution without the doping.

DOI： 10.1021/ma5024654

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Solid phase helical and crystal structures of poly(phenylacetylene)s with para-oligo ethylene oxy methylether moieties prepared with an organorhodium catalyst in ethanol 査読有り

Mawatari Y., Yoshida Y., Motoshige A., Motoshige R., Sasaki T., Tabata M.

European Polymer Journal 57 213 - 220 2014年08月

記述言語：英語掲載種別：研究論文（学術雑誌）

The stereoregular polymerization of phenylacetylenes with a para-(ethylene oxide)-methylether: p-O(CH2CH2O)mCH3 (m = 1 and 2) using a [Rh(norbornadine)Cl]2 - triethylamine catalyst was performed at 25 °C for 0.5 h to afford the corresponding helical bright-yellow and dark-violet polymers, P1Y and P2V, respectively. The diffuse reflective UV-vis spectra of P1Y exhibited a λmax at 470 nm, unlike the broad peak of P2V. The wide angle X-ray scattering (WAXS) pattern of P1Y was assigned to the columnar hexagonal crystals (CHC)s on which the stretched cis-transoid helices of P1Y are packed. The bent position of the 2CO bond in p-O1CH22CH 2O3CH3 was deduced from these crystals. In contrast, the WAXS pattern of P2V demonstrated the formation of a CHC with contracted cis-cisoid helices. The small peak at d = 3.4 Å for P2V was assigned to a π-stacking between each benzene ring and/or helical backbone. Their stable geometrical structures, helical diameters, and bent position calculated using the MMFF94 program agreed with those estimated using WAXS. © 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.eurpolymj.2014.05.010

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Structural determination of stretched helix and contracted helix having yellow and red colors of poly(2-ethynylnaphthalene) prepared with a [Rh(norbornadiene)Cl]<inf>2</inf>-triethylamine catalyst 査読有り

Mawatari Y., Motoshige A., Yoshida Y., Motoshige R., Sasaki T., Tabata M.

Polymer 55 ( 10 ) 2356 - 2361 2014年05月

記述言語：英語掲載種別：研究論文（学術雑誌）

The Rh-catalyzed polymerization of 2-ethynylnaphthalene (2EN) using ethanol or toluene solvents afforded helical poly(2-ethynylnaphthalene)s (P2EN)s, i.e., yellow-colored P2EN(Y) and red-colored P2EN(R) in good yields, respectively. The diffuse reflective UV-vis (DRUV-vis) spectra of P2EN(Y) and P2EN(R) in the solid phase showed broad absorption peaks at 445 nm and 510 nm, respectively. These helical and its crystal structures were investigated using wide angle X-ray scattering (WAXS), resonance laser Raman, and molecular mechanics calculation using MMFF94 force field. Based on these analyses, we found that P2EN(Y) was composed of stretched cis-transoid helices and P2EN(R) was composed of contracted cis-cisoid helices in which form intramolecular π-stacking by ca. 3.4 Å in distance between neighboring naphthyl rings. Furthermore, the contracted helix was energetically more stable than the stretched helix. The P2EN(Y) changed to a red-colored polymer, P2EN(Y-R), by immersion in toluene. This P2EN(Y-R) completely coincides with the P2EN(R) in its crystal structure and DRUV-vis spectrum. © 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2014.04.001

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Mutual conversion between stretched and contracted helices accompanied by a drastic change in color and spatial structure of poly(phenylacetylene) prepared with a [Rh(nbd)Cl]<inf>2</inf>-amine catalyst 査読有り

Motoshige R., Mawatari Y., Motoshige A., Yoshida Y., Sasaki T., Yoshimizu H., Suzuki T., Tsujita Y., Tabata M.

Journal of Polymer Science, Part A: Polymer Chemistry 52 ( 6 ) 752 - 759 2014年03月

記述言語：英語掲載種別：研究論文（学術雑誌）

The yellow-colored poly(phenylacetylene), Poly(Y), is obtained from phenylacetylene using a [Rh(nbd)Cl]2-NEt3 catalyst in ethanol at 25°C. The color of Poly(Y) drastically changes into red Poly(R) or reddish-black Poly(B) by immersion in acetylacetone or exposure to chloroform vapor, respectively. Poly(R) is also created from Poly(B) by contact with acetylacetone. Poly(Y) is regenerated from both Poly(R) and Poly(B) by reprecipitation from their chloroform solution into methanol. Wide-angle X-ray scattering (WAXS) patterns of Poly(Y) and Poly(R) correspond to a pseudohexagonal crystal called a columnar as stretched cis-transoid and contracted cis-cisoid helices, respectively. These helical diameters and pitch widths obtained from the WAXS measurements are agreed with those of MMFF94 calculation models. The smallest helical pitch width is 3.3 Å for Poly(R) and Poly(B). Moreover, information regarding the size and ordering of the vacant space within each polymer is estimated by using 129Xe NMR technique. © 2013 Wiley Periodicals, Inc.

DOI： 10.1002/pola.27065

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84893823546&origin=inward

Synthesis and solid state helix to helix rearrangement of poly(phenylacetylene) bearing n-octyl alkyl side chains 査読有り

Motoshige A., Mawatari Y., Yoshida Y., Motoshige R., Tabata M.

Polymer Chemistry 5 ( 3 ) 971 - 978 2014年02月

記述言語：英語掲載種別：研究論文（学術雑誌）

Highly stereoregular polymerisations of p-n-octyphenylacetylene (pOcPA) were performed using a [Rh(norbornadiene)Cl]2-triethylamine catalyst in ethanol at -20 and 25°C to afford yellow and orange polymers, Poly(Y) and Poly(O), in yields of 64 and 99%, respectively. The XRD patterns of Poly(Y) showed a hexagonal columnar crystal with a contracted cis-cisoid helix, HexaPoly(Y)CC. The XRD pattern of Poly(O) matched that of Poly(Y) when heated to 80°C. The heat treatment of HexaPoly(Y) CC at 100°C generated two tetragonal crystals: Tetra1Poly(R)CC, containing contracted cis-cisoid helices, and Tetra2Poly(R)CT, containing stretched cis-transoid helices. The helical diameters of HexaPoly(Y)CC before and after heat treatment were estimated using XRD and were consistent with the results of MMFF 94 calculations, although the n-octyl alkyl chains of HexaPoly(Y)CC and Tetra2Poly(R)CT did not have linear alkyl chains; a bend in the chains was confirmed by 13C CP-MAS NMR. When HexaPoly(Y)CC was heated to 100°C in the solid phase, the λmax in the diffuse reflective UV-vis spectra shifted from 448 nm to 565 nm. Furthermore, the endothermic transition for HexaPoly(Y)CC occurred at 100°C in the DSC trace. Therefore, these data corroborated the assertion that HexaPoly(Y)CC thermally converted into Tetra1Poly(R)CC and Tetra2Poly(R)CT. © 2014 The Royal Society of Chemistry.

DOI： 10.1039/c3py01000g

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84891450393&origin=inward

Synthesis and helix pitch control of π-conjugated helical polymers with accordion-like oscillation 査読有り

Yoshida Y., Mawatari Y., Tabata M.

Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry 72 ( 3 ) 292 - 302 2014年01月

担当区分：筆頭著者記述言語：英語掲載種別：記事・総説・解説・論説等（学術雑誌）

Poly(alkyl propiolate)s (PAP), e.g., Poly(n-heptyl propiolate (PnHepP) and Poly((s)-2-octyl propiolate) (Ps2OctP) having an achiral or a chiral ester side chain were stereoregularly prepared with a Rh complex catalyst, [Rh(nbd Cl] 2 (nbd = norbornadiene), at 40 °C in methanol, respectively. The temperature dependence 1H and 13 C NMR spectra of PAPs and their spectral simulations indicated that the restricted rotation around the ester O-C bond takes place through the socalled 3-site jump conformation. The spectra also exhibited that the helical conjugated main-chain of Ps2OctP was largely oscillating between the sequences of contracted helix and stretched helix in the time scale of the NMRs, although the degree of the oscilation of PnHepP was fairly small compared to that of Ps2OctP. The UV-vis and IR spectra of them supported that PAPs have at least two helical conformations, i.e., contracted and stretched helices. Therefore, these spectra supported the oscillation of the helix along the main-chain axis. The proposed model calculated by MMFF94 also indicated the accordion-like helix oscillation of contracted and stretched helices (HELIOS) of PAPs which was synchronized with restricted 3-site jump rotation around the ester O-C bond in the side-chain.

DOI： 10.5059/yukigoseikyokaishi.72.292

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84902346091&origin=inward

Contracted Helix to Stretched Helix Rearrangement of an Aromatic Polyacetylene Prepared in n-Hexane with [Rh(norbornadiene)Cl]2 -triethylamine Catalyst 査読有り国際誌

Asahi Motoshige, Yasuteru Mawatari, Ranko Motoshigea, Yoshiaki Yoshida, and Masayoshi Tabata

Journal of Polymer Science Part A: Polymer Chemistry ( John Wiley & Sons ) 51 ( 24 ) 5177 - 5183 2013年10月

Helix oscillation of polyacetylene esters detected by dynamic 1H NMR, IR, and UV-vis methods in solution 査読有り国際誌

Yoshiaki Yoshida, Yasuteru Mawatari, Asahi Motoshige, Ranko Motodshige, Toshifumi Hiraoki, Masayoshi Tabata

Polymer. Chemistry ( Royal Society of Chemistry ) 4 ( 10 ) 2982 - 2988 2013年03月

Accordion-like Oscillation of Contracted and Stretched Helices of Polyacetylenes Synchronized with the Restricted Rotation of Side Chains 査読有り国際誌

Yoshiaki Yoshida, Yasuteru Mawatari, Asahi Motoshige, Ranko Motoshige, Toshifumi Hiraoki, Manfred Wagner, Klaus Müllen, Masayoshi Tabata

Journal of the American Chemical Society ( ACS Publications ) 135 ( 10 ) 4110 - 4116 2013年02月

Irreversible Helix Rearrangement from Cis-transoid to Cis-cisoid in Poly(p-n-hexyloxyphenylacetylene) Induced by Heat-treatment in Solid Phase 査読有り国際誌

Asahi Motoshige, Yasuteru Mawatari, Yoshiaki Yoshida, Chigusa Seki, Haruo Matsuyama, and Masayoshi Tabata

Journal of Polymer Science Part A: Polymer Chemistry ( John Wiley & Sons ) 50 ( 15 ) 3008 - 3015 2012年08月

Geometrical Structures in Solution and Solid Phase of Poly(propargyl ester)s Prepared by Using a [Rh(norbornadiene)Cl]2-cocatalyst 査読有り国際誌

Yoshiaki Yoshida, Yasuteru Mawatari, Chigusa Seki, Toshifumi Hiraoki, Haruo Matsuyama, and Masayoshi Tabata

Polymer ( Elsevier Ltd. ) 52 ( 18 ) 3917 - 3924 2011年08月

Cis and trans radicals generated in helical poly(propargyl acetate)s prepared using a [Rh(norbornadiene)Cl]2 catalyst 査読有り国際誌

Yoshiaki Yoshida, Yasuteru Mawatari, Chigusa Seki, Toshifumi Hiraoki, Haruo Matsuyama, Masayoshi Tabata

Polymer ( Elsevier Ltd. ) 52 ( 3 ) 646 - 651 2011年02月

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