研究者詳細 - 西原　康師

論文 - 西原　康師

分割表示 197 件中 61 - 80 件目／全件表示 >>

Synthesis and Physicochemical Properties of Piceno[4,3-b:9,10-b′]dithiophene Derivatives and Their Application in Organic Field-Effect Transistors 査読

Keita Hyodo, Ryota Toyama, Hiroki Mori, Yasushi Nishihara

ACS Omega 2 ( 1 ) 308 - 315 2017年1月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：American Chemical Society

Efficient synthesis and characterization of several piceno[4,3-b:9,10-b′]dithiophene (PiDT) derivatives by Negishi coupling, epoxidation, and Lewis acid-catalyzed cycloaromatization sequences and their potential utility in organic field-effect transistors (OFETs) have been reported. PiDT derivatives, with extended π-electron systems, showed high air stability due to their deep highest occupied molecular orbital energy levels (around -5.6 eV). OFET devices based on 2,11-dioctylated PiDT (C8-PiDT) showed excellent hole mobility, as high as 2.36 cm2 V-1 s-1. Their structure-property relationships were investigated by X-ray diffraction and atomic force microscopy.

DOI： 10.1021/acsomega.7b00015

Bis[1]benzothieno[2,3-d:2 ',3 '-d ']anthra[1,2-b:5,6-b ']dithiophene: synthesis, characterization, and application to organic field-effect transistors 査読

Keita Hyodo, Hideki Hagiwara, Ryota Toyama, Hiroki Mori, Shin-ichi Soga, Yasushi Nishihara

RSC ADVANCES 7 ( 10 ) 6089 - 6092 2017年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

We report the straightforward synthetic method and characterization of bis[1]benzothieno[2,3-d:2',3'-d']anthra[1,2-b:5,6-b']dithiophene (BBTADT) having nine aromatic rings fused without solubilizing groups. The highest mobility of fabricated OFETs utilizing BBTADT exhibited 2.7 x 10(-2) cm(2) V-1 s(-1) in polycrystalline films formed by vapor deposition, depending on the annealing temperatures of a substrate.

DOI： 10.1039/c6ra27455b

Transistor Properties of 2,7-Dialkyl-Substituted Phenanthro[2,1-b:7,8-b '] dithiophene

Yoshihiro Kubozono, Keita Hyodo, Shino Hamao, Yuma Shimo, Hiroki Mori, Yasushi Nishihara

Scientific Reports 6 38535 2016年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：NATURE PUBLISHING GROUP

A new phenacene-type molecule with five fused aromatic rings was synthesized: 2,7-didodecylphenanthro[2,1-b: 7,8-b'] dithiophene ((C12H25)(2)-i-PDT), with two terminal thiophene rings. Field-effect transistors (FETs) using thin films of this molecule were fabricated using various gate dielectrics, showing p-channel normally-off FET properties with field-effect mobilities (mu) greater than 1cm(2) V-1 s(-1). The highest mu value in the thin-film FETs fabricated in this study was 5.4 cm(2) V-1 s(-1), when a 150 nm-thick ZrO2 gate dielectric was used. This implies that (C12H25)(2)-i-PDT is very suitable for use in a transistor. Its good FET performance is fully discussed, based on electronic/topological properties and theoretical calculations.

DOI： 10.1038/srep38535

Highly Selective Synthesis of Multi-substituted Olefins Mediated by Zirconocene Complexes

Keita Hyodo, Yasushi Nishihara

JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN 74 ( 8 ) 792 - 802 2016年8月

記述言語：日本語出版者・発行元：SOC SYNTHETIC ORGANIC CHEM JPN

In this paper, the efficient methodology for the synthesis of multi-substituted olefins by using zirconocene complexes is described. The key step is regioselective formation of zirconacyclopentenes from alkynylboron and alkynylsilane compounds. The subsequent Negishi and Suzuki-Miyaura coupling reactions of C-B and C-Zr bonds give rise to multi-substituted olefins. The developed reaction can be applicable to the synthesis of various functional molecules, for example, an anti-cancer agent. In addition, the mechanism for a regioselective formation of zirconacyclopentenes is analyzed by reactions of alkynylboronates and a zirconocene (II) complex. As a result, it is disclosed that an electrostatic interaction effected the regioselective formation of zirconacyclopentenes. The synthesis of various unprecedented tri- and tetra-alkylated olefins using beta-hydrogen containing alkyl electrophiles and alkylzinc reagents as coupling partners in regio- and stereocontrolled manners is also described.

Synthesis of Multisubstituted Olefins through Regio- and Stereoselective Addition of Interelement Compounds Having B-Si, B-B, and Cl-S Bonds to Alkynes, and Subsequent Cross-Couplings

Masayuki Iwasaki, Yasushi Nishihara

CHEMICAL RECORD 16 ( 4 ) 2031 - 2045 2016年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-V C H VERLAG GMBH

Multisubstituted olefins are fundamental motifs in organic compounds. In this account, we describe the synthesis of organic molecules bearing an olefinic moiety by the transition-metal-catalyzed regio- and stereoselective addition of a variety of interelement compounds to alkynes. Regio- and stereoselective silaboration, diborylation, and chlorothiolation have been achieved by using the transition-metal catalysts. The subsequent cross-coupling reactions of the boron-containing alkenes to install various aryl groups afforded the corresponding tri- and tetraarylated olefins. This account describes our research on the highly regio- and stereoselective synthesis of multifunctionalized olefins such as tetraarylethenes with four different aryl groups.

DOI： 10.1002/tcr.201600017

Palladium-Catalyzed Regio- and Stereoselective Carbothiolation of Terminal Alkynes with Azolyl Sulfides

Masayuki Iwasaki, Nikola Topolovcan, Hao Hu, Yugo Nishimura, Glwadys Gagnot, Rungsaeng Na Nakorn, Ramida Yuvacharaskul, Kiyohiko Nakajima, Yasushi Nishihara

ORGANIC LETTERS 18 ( 7 ) 1642 - 1645 2016年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

Palladium-catalyzed carbothiolation of terminal alkynes with azolyl sulfides affords various 2-(azolyl)alkenyl sulfides with perfect regio- and stereoselectivities. The present addition reaction proceeded through a direct cleavage of carbon-sulfur bonds in azolyl sulfides. The resulting adducts that are useful intermediates in organic synthesis are further transformed to multisubstituted olefins containing azolyl moieties.

DOI： 10.1021/acs.orglett.6b00503

Highly crystalline, low band-gap semiconducting polymers based on phenanthrodithiophene-benzothiadiazole for solar cells and transistors

Hiroki Mori, Hikaru Nonobe, Yasushi Nishihara

POLYMER CHEMISTRY 7 ( 8 ) 1549 - 1558 2016年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

New PDT-based polymers were combined with two types of benzothiadiazole (BT) derivatives to improve their crystallinity and solar cell performance. These polymers show several advantages, including strong intermolecular interactions, deep HOMO energy levels, and a dense packing structure with a short pi-pi stacking distance of 3.5-3.6 angstrom. Combinations of PDT and BT units in polymers formed highly crystalline thin films with a long-range order, even in films blended with a fullerene derivative. This suggests that the introduction of optimal acceptor units may increase the regularity of the polymers, leading to effective pi-pi overlaps between the polymer backbones. However, although the present polymers also formed an appropriate phase separation structure in blended films, in fabricated solar cell devices they yielded low power conversion efficiencies (PCEs) not exceeding 3.8%. GI-WAXS analysis revealed that both polymers were present in a predominantly edge-on orientation. This unsuitable orientation for PSCs prevented efficient carrier transport and reduced charge collection efficiency, resulting in low J(sc) and thus low PCE. On the other hand, these polymers also formed highly oriented edge-on structures on n(+)-Si/SiO2 substrates, which are suitable for high-performance field-effect transistors (FETs), and a fabricated FET device showed a hole mobility as high as 0.18 cm(2) V-1 s(-1).

DOI： 10.1039/c5py01878a

Molecular mechanism of palladium-catalyzed cyanoesterification of methyl cyanoformate onto norbornene 査読

石塚拓也, 奥田靖浩, Szilagyi, R. K, 森聖治, 西原康師

Dalton Trans. 45 ( 18 ) 7786 - 7793 2016年

Palladium-catalysed direct thiolation and selenation of aryl C-H bonds assisted by directing groups 査読

Masayuki Iwasaki, Yasushi Nishihara

DALTON TRANSACTIONS 45 ( 39 ) 15278 - 15284 2016年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

Direct chalcogenation of aryl C-H bonds has attracted a lot of attention because arylcharcogen compounds represent useful building blocks in bioactive molecules and functional organic materials. Very recently, chelate-assisted intermolecular direct thiolation and selenation have been developed using various transition-metal catalysts such as palladium, rhodium, nickel, copper and ruthenium. In addition, an appropriate choice of directing group can be used to control the reaction sites. This highlight review focuses on the recent advances in catalytic C-H chalcogenation.

DOI： 10.1039/c6dt02167k

Synthesis of Multisubstituted Triphenylenes and Phenanthrenes by Cascade Reaction of o-Iodobiphenyls or (Z)-β-Halostyrenes with o-Bromobenzyl Alcohols through Two Sequential C-C Bond Formations Catalyzed by a Palladium Complex

Masayuki Iwasaki, Yasuhiro Araki, Shohei Iino, Yasushi Nishihara

J. Org. Chem. 80 ( 18 ) 9247 - 9263 2015年9月

Impact of Alkyl Side Chains on Thin-film Transistor Performances in Phenanthrodithiophene-Isoindigo Copolymers

Shuhei Nishinaga, Hiroki Mori, Yasushi Nishihara

CHEMISTRY LETTERS 44 ( 7 ) 998 - 1000 2015年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHEMICAL SOC JAPAN

Organic field-effect transistor (OFET) characteristics of phenanthrodithiophene (PDT)-isoindigo (IID) copolymers with different alkyl chains (12OD and BOBO) as an active layer, and their structure property relationships are described. The fabricated 12OD-based OFET device exhibited hole mobility of 0.16 cm(2)V(-1) s(-1). Grazing-incidence wide-angle X-ray scattering (GIWAXS) analysis revealed that 12OD formed highly ordered edge-on structure, whereas the BOBO film showed amorphous-like structure with no obvious pi-stacking crystallites. This may be attributed to a large steric hindrance of branched side chains in the BOBO polymer, which suppresses effective pi-pi overlaps between the adjacent polymer backbones.

DOI： 10.1246/cl.150357

Phenanthrodithiophene-Isoindigo Copolymers: Effect of Side Chains on Their Molecular Order and Solar Cell Performance

Shuhei Nishinaga, Hiroki Mori, Yasushi Nishihara

MACROMOLECULES 48 ( 9 ) 2875 - 2885 2015年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

The synthesis;,characterization, and solar cell application of newly developed semiconducting polymers containing phenanthro[1,2-b:8,7-b']dithiophene (PDT) combined with A bis(thienyl)isoindigo (IID) unit are,described. The polymers with longer, alkyl Chains are sufficiently soluble to be compatible with the processes required to manufacture solar cells. In conventional solar cell, devices, polymers with all branched alkyl chains tend to form a higher proportion of a well-ordered face-on crystallite in the pi-stack direction than those with both linear and branched alkyl chains, which significantly improves the Ell factor (FF), resulting in higher power conversion efficiency (PCE). In terms of optimizing the alkyl chain lengths; the installation of longer alkyl side chains on the polymer backbone leads to low molecular weight polymer, which may promote a large phase separation. As a result, the polymers 12OD and BOBO, beating shorter alkyl groups, performed better, and a BOBO polymer-based solar cell (PSC) showed the best PCE value up to 3.83%. In the inverted PSCs, the polymers with all branched alkyl chains have a higher face-on ratio than those with both linear and branched alkyl chains. Because of their improved J(sc), inverted PSCs with BOBO/PC71BM gave the best performance, with a PCE up to 5.28%. Although an obvious dependence of photovoltaic properties on molecular order-was observed in conventional solar cell devices, no trend was observed in inverted cells, Possibly attributable to their amorphous nature, which arises from the axisymmetrical structure of PDT, leading to less effective pi-pi overlap and low crystallinity.

DOI： 10.1021/acs.macromol.5b00622

Erratum: Transistor application of new picene-type molecules, 2,9-dialkylated phenanthro[1,2-b:8,7-b′]dithiophenes (Journal of Materials Chemistry C (2015) 3 DOI: 10.1039/c4tc02413c) 査読

Yoshihiro Kubozono, Keita Hyodo, Hiroki Mori, Shino Hamao, Hidenori Goto, Yasushi Nishihara

Journal of Materials Chemistry C 3 ( 12 ) 2960 2015年3月

Synthesis, Characterization, and Solar Cell and Transistor Applications of Phenanthro[1,2-b:8,7-b ']dithiophene-Diketopyrrolopyrrole Semiconducting Polymers

Hiroki Mori, Masato Suetsugu, Shuhei Nishinaga, Ning-hui Chang, Hikaru Nonobe, Yasuhiro Okuda, Yasushi Nishihara

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY 53 ( 5 ) 709 - 718 2015年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

Synthesis, characterization, and polymer solar cell and transistor application of a series of phenanthro[1,2-b:8,7-b]dithiophene-based donor-acceptor (D-A)-type semiconducting polymers combined with a diketopyrrolopyrrole unit are reported. The present polymers showed some unique features such as strong aggregation behavior, high thermal stability, and short - stacking distance (3.5-3.6 angstrom), which are suitable for high performance organic materials. In addition, they have a significantly extended absorption up to 1000 nm with a band gap of ca. 1.2 eV. However, such strong intermolecular interaction reduced their solubility and molecular weights, which resulted in low crystalline nature and moderate field-effect mobility of 0.01 cm(2) V-1 s(-1). Furthermore, such strong aggregation behavior led to the large-scale phase separation in the blend films, which may prevent the effective photocurrent generation, limiting J(sc) and power conversion efficiency of 2.0%. (c) 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 709-718

DOI： 10.1002/pola.27500

Transistor application of new picene-type molecules, 2,9-dialkylated phenanthro[1,2-b:8,7-b ']dithiophenes

Yoshihiro Kubozono, Keita Hyodo, Hiroki Mori, Shino Hamao, Hidenori Goto, Yasushi Nishihara

JOURNAL OF MATERIALS CHEMISTRY C 3 ( 10 ) 2413 - 2421 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ROYAL SOC CHEMISTRY

Field-effect transistors (FETs) have been fabricated with thin films of a series of 2,9-dialkylated phenanthro [1,2-b:8,7-b'] dithiophene derivatives (C-n-PDTs). The FET characteristics of C-n-PDT thin-film FETs with an SiO2 gate dielectric as well as high-k gate dielectrics were recorded, and the dependence of the field-effect mobility, mu, on the number (n) of carbon atoms in the alkyl chains was investigated, showing that the 2,9-didodecylphenanthro[1,2-b:8,7-b'] dithiophene (C-12-PDT) thin-film FET displays superior properties, with mu s as high as 1.8 cm(2) V-1 s(-1) for the SiO2 gate dielectric and 2.2 cm(2) V-1 s(-1) for the HfO2 gate dielectric. The average mu values, <mu >, reach 1.1(5) and 1.8(6) cm(2) V-1 s(-1), respectively, for the SiO2 and ZrO2 gate dielectrics. Low-voltage operation, showing an absolute average threshold voltage <|V-th|> of similar to 11 V, was implemented, together with the above high <mu > of similar to 2 cm(2) V-1 s(-1). Also, a flexible FET was fabricated with a parylene gate dielectric. The results of this study show the potential of the C-12-PDT molecule for application in a high-performance transistor.

DOI： 10.1039/c4tc02413c

A divergent synthesis of 3,10-dialkylpicenes

Xi-Chao Chen, Shuhei Nishinaga, Yasuhiro Okuda, Jia-Ji Zhao, Jie Xu, Hiroki Mori, Yasushi Nishihara

Organic Chemistry Frontiers 2 ( 5 ) 536 - 541 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CHINESE CHEMICAL SOC

A series of 3,10-dialkylated picenes has been synthesized from 3,10-dimethoxypicene through a divergent approach involving Ni-catalyzed alkynylation of a C-O bond, alkylation, and hydrogenation.

DOI： 10.1039/c5qo00039d

Recent progresses in organic field effect transistors based on π-conjugated organic molecules

Hiroki Mori, Yasushi Nishihara

Kobunshi 63 ( 12 ) 866 - 870 2014年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Society of Polymer Science

Organic field-effect transistors (OFETs) have gained considerable interest as the key elements for realizing future ubiquitous electronics because they have a large number of advantages such as the flexibility, light-weight, and ease of design. In this article, recent material developments in this field, including phenacene-type molecules, thienoacene derivatives, and a series of donor-acceptor (D-A)-type polymers, are summarized. Phenacene-type molecules possess a low HOMO level and a wide band gap. Recently, among phenacene-type molecules, picene, [6]phenacene, and [7]phenacene have been recognized as unique molecules because using them high field-effect mobility in the transistors can be realized. In addition, in some cases the FET properties were found to be highly improved by an incorporation of alkyl chains to the parent motif and one can expect to apply these molecules to a solution-process owing to a high solubility in common organic solvents. Furthermore, recent progress of diketopyrrolopyrrole (DPP) and isoindigo (IID)-based D-A polymers showing high mobility are introduced.

Palladium-Catalyzed pen-Selective Chalcogenation of Naphthylamines with Diaryl Disulfides and Diselenides via C-H Bond Cleavage

Masayuki Iwasaki, Wataru Kaneshika, Yuta Tsuchiya, Kiyohiko Nakajima, Yasushi Nishihara

JOURNAL OF ORGANIC CHEMISTRY 79 ( 23 ) 11330 - 11338 2014年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

A palladium-catalyzed and picolinamide-directed C-H thiolation of naphthylamine derivatives with diaryl disulfides has been developed to provide a convenient route to 8-sulfenyl-1-naphthylamines. The reaction proceeds via a 5-membered palladacycle intermediates to afford the peri-thiolated products exclusively, in contrast to the conventional ortho-functionalization. Moreover, the related direct selenation was also achieved with diaryl diselenides, giving the corresponding selenated products with perfect site-selectivity.

DOI： 10.1021/jo502274t

Iron-Induced Regio- and Stereoselective Addition of Sulfenyl Chlorides to Alkynes by a Radical Pathway 査読

Masayuki Iwasaki, Tomoya Fujii, Kiyohiko Nakajima, Yasushi Nishihara

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 53 ( 50 ) 13880 - 13884 2014年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-V C H VERLAG GMBH

The radical addition of the ClS sigma-bond in sulfenyl chlorides to various CC triple bonds has been achieved with excellent regio- and stereoselectivity in the presence of a catalytic amount of a common iron salt. The reaction is compatible with a variety of functional groups and can be scaled up to the gram-scale with no loss in yield. As well as terminal alkynes, internal alkynes underwent stereodefined chlorothiolation to provide tetrasubstituted alkynes. Preliminary mechanistic investigations revealed a plausible radical process involving a sulfur-centered radical intermediate via iron-mediated homolysis of the ClS bond. The resulting chlorothiolation adducts can be readily transformed to the structurally complex alkenyl sulfides by cross-coupling reactions. The present reaction can also be applied to the complementary synthesis of the potentially useful bis-sulfoxide ligands for transition-metal-catalyzed reactions.

DOI： 10.1002/anie.201408121

Chelate-Assisted Direct Selenation of Aryl C-H Bonds with Diselenides Catalyzed by Palladium 査読

Masayuki Iwasaki, Yuta Tsuchiya, Kiyohiko Nakajima, Yasushi Nishihara

ORGANIC LETTERS 16 ( 18 ) 4920 - 4923 2014年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

A direct selenation of inert C-H bonds of benzamide derivatives and their related compounds with diselenides has been achieved with the palladium catalyst. The reaction was compatible with a variety of functional groups, including a bromo group. Primitive mechanistic insights revealed that the reaction proceeded through a C H bond cleavage and the sequential oxidative addition of diselenides. The present synthetic method can be applied to the facile synthesis of selenoxanthone which can be regarded as promising heterocyclic materials.

DOI： 10.1021/ol502439m

　前のページ - 次のページ　

1
2
3
4
5
6
7
8
9
10