研究者詳細 - 山口　茂弘

論文 - 山口　茂弘

分割表示 377 件中 161 - 180 件目／全件表示 >>

Hybridization of a Flexible Cyclooctatetraene Core and Rigid Aceneimide Wings for Multiluminescent Flapping pi Systems 査読有り

Yuan Chunxue, Saito Shohei, Camacho Cristopher, Kowalczyk Tim, Irle Stephan, Yamaguchi Shigehiro

CHEMISTRY-A EUROPEAN JOURNAL 20 巻 ( 8 ) 頁： 2193 - 2200 2014年2月

Hydroxyphenyl-Substituted Benzophosphole Oxides: Impact of the Intramolecular Hydrogen Bond on the Fluorescence Properties

Fukazawa Aiko, Osaki Hiroshi, Yamaguchi Shigehiro

ASIAN JOURNAL OF ORGANIC CHEMISTRY 3 巻 ( 2 ) 頁： 122 - 127 2014年2月

Hydroxyphenyl-Substituted Benzophosphole Oxides: Impact of the Intramolecular Hydrogen Bond on the Fluorescence Properties 査読有り

Aiko Fukazawa, Hiroshi Osaki, Shigehiro Yamaguchi

ASIAN JOURNAL OF ORGANIC CHEMISTRY 3 巻 ( 2 ) 頁： 122 - 127 2014年2月

COD ID: 4120128 査読有り

Nagura Kazuhiko, Saito Shohei, Yusa Hitoshi, Yamawaki Hiroshi, Fujihisa Hiroshi, Sato Hiroyasu, Shimoikeda Yuichi, Yamaguchi Shigehiro

Crystallography Open Database 2014年

Constraint-induced structural deformation of planarized triphenylboranes in the excited state 査読有り

Tomokatsu Kushida, Cristopher Camacho, Ayumi Shuto, Stephan Irle, Masayasu Muramatsu, Tetsuro Katayama, Syoji Ito, Yutaka Nagasawa, Hiroshi Miyasaka, Eri Sakuda, Noboru Kitamura, Zhiguo Zhou, Atsushi Wakamiya, Shigehiro Yamaguchi

CHEMICAL SCIENCE 5 巻 ( 4 ) 頁： 1296 - 1304 2014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

Triphenylboranes planarized with three methylene bridges exhibited dual fluorescence bands around 340 and 400 nm despite their structural constraint. To elucidate the origin, their excited state dynamics were experimentally and theoretically studied. The measurements of fluorescence lifetimes and transient absorption spectra indicated that the planarized triphenylboranes adopt two local minimum structures in the lowest-energy excited singlet (S-1) state. The TD-DFT potential energy surface of the S-1 state possesses at least two minimum energy structures associated with a planar and a bowl-shaped molecular structure. The theoretical S-1-S-0 transition energies at these geometries were in good agreement with the experimentally observed values. These results indicated that the plane-to-bowl structural relaxation in the S-1 state is the origin of the dual fluorescence. Based on the calculated partial atomic charge on the boron atom, the structural deformation to the bowl-shaped structure results in an increase in the electron density on the boron center. Thus, the enhanced intramolecular charge-transfer character plays a role in this structural deformation. Similar behavior was also observed for trigonally pi-expanded planarized borane derivatives. These results provide an important implication that structural constraint in a planar fashion is not only a strategy to construct a rigid skeleton, but also a viable mechanism to impart flexibility to the skeleton.

DOI： 10.1039/c3sc52751d

Web of Science

pi-Extended Planarized Triphenylboranes with Thiophene Spacers

Shuto Ayumi, Kushida Tomokatsu, Fukushima Tatsuya, Kaji Hironori, Yamaguchi Shigehiro

ORGANIC LETTERS 15 巻 ( 24 ) 頁： 6234 - 6237 2013年12月

Modification and Unexpected Reactivity of 2-Borylbenzaldimines: Acylated and Silylated Derivatives as Well as Dimeric Compounds

Neue Benedikt, Wakarniya Atsushi, Froehlich Roland, Wibbeling Birgit, Yamaguchi Shigehiro, Wuerthwein Ernst-Ulrich

JOURNAL OF ORGANIC CHEMISTRY 78 巻 ( 23 ) 頁： 11747 - 11755 2013年12月

A Radical Anion of Structurally Constrained Triphenylborane

Kushida Tomokatsu, Yamaguchi Shigehiro

ORGANOMETALLICS 32 巻 ( 22 ) 頁： 6654 - 6657 2013年11月

Diarylated Bi(thieno[2,3-c]thiophene)s: A Ring-Fusing Strategy for Controlling the Molecular Alignment of Oligoarenes 査読有り

Fukazawa Aiko, Kishi Daisuke, Tanaka Yuki, Seki Shu, Yamaguchi Shigehiro

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 52 巻 ( 46 ) 頁： 12091 - 12095 2013年11月

Constraint-induced Structural Deformation of Planarized Triphenylboranes in the Excited State 査読有り

T. Kushida, C. Camacho, A. Shuto, S. Irle, M. Muramatsu, T. Katayama, S. Ito, Y. Nagasawa, H. Miyasaka, E. Sakuda, N. Kitamura, Z. Zhou, A. Wakamiya, and S. Yamaguchi

Chem. Sci. ５巻頁： 1296-1304 2013年11月

Photochemical Double 5-exo Cyclization of Alkenyl-Substituted Dithienylacetylenes: Efficient Synthesis of Diarylated Dithienofulvalenes 査読有り

Fukazawa Aiko, Karasawa Takashi, Zhang Hongyu, Minemura Kazumitsu, Camacho Cristopher, Wang Jian, Irle Stephan, Yamaguchi Shigehiro

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 52 巻 ( 40 ) 頁： 10519 - 10523 2013年9月

Diarylated Bi(thieno[2,3-c]thiophene)s: A Ring-fusing Strategy for Controlling the Molecular Alignment of Oligoarenes 査読有り

A. Fukazawa, D. Kishi, Y. Tanaka, S. Seki, and S. Yamaguchi

Angew. Chem. Int. Ed. 52 巻頁： 12091-12095 2013年9月

Photochemical Double 5-exo-dig Cyclization of Alkenyl-substituted Dithienylacetylenes: Efficient Synthesis of Diarylated Dithienofulvalenes 査読有り

A. Fukazawa, T. Karasawa, H. Zhang, K. Minemura, C. Camacho, J. Wang, S. Irle, and S. Yamaguchi

Angew. Chem. Int. Ed. 52 巻頁： 10519-10523 2013年8月

Amplified Spontaneous Emission in Pentathienoacene Dioxides by Direct Optical Pump and by Energy Transfer: Correlation with Photophysical Parameters

Juan Casado, Victor Hernandez, Juan T. Lopez Navarrete, Manuel Algarra, Demetrio A. da Silva Filho, Shigehiro Yamaguchi, Raquel Rondao, J. Sergio Seixas de Melo, Victor Navarro-Fuster, Pedro G. Boj, Maria A. Diaz-Garcia

ADVANCED OPTICAL MATERIALS 1 巻 ( 8 ) 頁： 588 - 599 2013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

Amplified spontaneous emission (ASE) is observed, under optical pump, in polystyrene films doped with two pentathienoacene derivatives functionalised with thienyl-S, S-dioxide groups (compounds 2 and 3). The effect of the dioxide groups on the ASE properties is analysed by comparing the performance with that of its corresponding non-oxidized analogue (1). Films containing either 2 or 3 show ASE at 511 and 574 nm, respectively, when excited directly (at 435 nm) on their absorption bands, showing thresholds and linewidths larger than those obtained from films doped with 1, pumped at 355 nm. ASE is also observed under excitation at 355 nm, in samples containing 1 (host) and either 2 or 3 (guests), due to energy transfer from host to guest. For the blends with 3, the ASE threshold is lower than that obtained when the films are excited directly. Results are interpreted in terms of the photophysical parameters such as absorption capacity, fluorescence efficiency, singlet-to-triplet intersystem crossing leading to triplet-triplet re-absorptions, bimolecular energy-transfer efficiency, efficiency of internal conversion process, etc. State-of-the-art quantum chemical calculations are used in the interpretation of the experimental results.

DOI： 10.1002/adom.201300155

Web of Science

Boracyclophanes: Modulation of the sigma/Character in Boron-Benzene Interactions

Kushida Tomokatsu, Yamaguchi Shigehiro

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 52 巻 ( 31 ) 頁： 8054 - 8058 2013年7月

Distinct Responses to Mechanical Grinding and Hydrostatic Pressure in Luminescent Chromism of Tetrathiazolylthiophene 査読有り

K. Nagura, S. Saito, H. Yusa, H. Yamawaki, H. Fujihisa, H. Sato, Y. Shimoikeda, and S. Yamaguchi

J. Am. Chem. Soc. 135 巻頁： 10322-10325 2013年7月

Distinct responses to mechanical grinding and hydrostatic pressure in luminescent chromism of tetrathiazolylthiophene. 査読有り

Nagura K, Saito S, Yusa H, Yamawaki H, Fujihisa H, Sato H, Shimoikeda Y, Yamaguchi S

Journal of the American Chemical Society 135 巻 ( 28 ) 頁： 10322 - 10325 2013年7月

A Pentacoordinate Boron-Containing pi-Electron System with CI-B-CI Three-Center Four-Electron Bonds 査読有り

Dou Chuandong, Saito Shohei, Yamaguchi Shigehiro

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 135 巻 ( 25 ) 頁： 9346 - 9349 2013年6月

A π-Conjugated System with Flexibility and Rigidity that Shows Environment-Dependent RGB Luminescence 査読有り

C. Yuan, S. Saito, C. Camacho, S. Irle, I. Hisaki, S. Yamaguchi

J. Am. Chem. Soc. 135 巻 ( 24 ) 頁： 8842 - 8845 2013年6月

記述言語：英語掲載種別：研究論文（学術雑誌）

発光性の有機分子は、有機ELやバイオイメージングなどの分野で幅広く用いられ，ますますその重要性は増している。本研究では、新しい分子設計の指針として「剛直性と柔軟性のハイブリッド」というコンセプトを提唱し、堅い骨格と柔らかい骨格のそれぞれの長所を活かした新しい発光性材料を開発した。この材料は、一種類の分子からなるにもかかわらず、環境に応じて分子が形を変えることで光の３原色であるRGB（Red、Green、Blue）の３色の発光を示すことができる。ポリマー薄膜に分散させた状態では青色に光り、溶媒に溶かした状態では緑色に光り、分子が集まった結晶状態では赤色に光る。これら３色の光は、それぞれ、分子がV字型に曲がった形、平面型に伸びた形、V字型で積み上がった形から発せられる。エネルギーの大きく異なるRGBの３色の発光を、一つの有機分子で励起波長を変えずに実現したのはこれが初めてとなる。

DOI： 10.1021/ja404198h

Web of Science

PubMed

A π-Conjugated System with Flexibility and Rigidity that Shows Environment-Dependent RGB Luminescence 査読有り

C. Yuan, S. Saito, C. Camacho, S. Irle, I. Hisaki, and S. Yamaguchi

J. Am. Chem. Soc. 135 巻頁： 8842-8845 2013年5月

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