論文 - 岡本　秀毅

Photochemical synthesis and device application of acene–phenacene hybrid molecules, dibenzo[n]phenacenes (n = 5–7) 査読

Yanting Zhang, Ritsuko Eguchi, Shino Hamao, Kenta Goto, Fumito Tani, Minoru Yamaji, Yoshihiro Kubozono, Hideki Okamoto

Chemical Communications   57 ( 39 )   4768 - 4771   2021年

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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）  

DOI： 10.1039/d1cc01294k

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Synthesis of [7]phenacene incorporating tetradecyl chains in the axis positions and its application in field-effect transistors 査読 国際共著 国際誌

Hideki Okamoto, Shino Hamao, Keiko Kozasa, Yanan Wang, Yoshihiro Kubozono, Yong-He Pan, Yu-Hsiang Yen, Germar Hoffmann, Fumito Tani, Kenta Goto

Journal of Materials Chemistry C   8 ( 22 )   7422 - 7435   2020年

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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）  

DOI： 10.1039/d0tc00272k

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Synthesis of the extended phenacene molecules, [10]phenacene and [11]phenacene, and their performance in a field-effect transistor 査読 国際共著 国際誌

Hideki Okamoto, Shino Hamao, Ritsuko Eguchi, Hidenori Goto, Yasuhiro Takabayashi, Paul Yu-Hsiang Yen, Luo Uei Liang, Chia-Wei Chou, Germar Hoffmann, Shin Gohda, Hisako Sugino, Yen-Fa Liao, Hirofumi Ishii, Yoshihiro Kubozono

Scientific Reports   9 ( 1 )   4009 - 4009   2019年12月

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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）  

DOI： 10.1038/s41598-019-39899-4

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その他リンク： http://www.nature.com/articles/s41598-019-39899-4

Solvent-induced multicolour fluorescence of amino-substituted 2,3-naphthalimides studied by fluorescence and transient absorption measurements 査読

Mayu Fujii, Misa Namba, Minoru Yamaji, Hideki Okamoto

PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES   15 ( 7 )   842 - 850   2016年

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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：ROYAL SOC CHEMISTRY  

A series of amino-2,3-naphthalimide derivatives having the amino functionality at 1-, 5-and 6-positions (1ANI, 5ANI and 6ANI, respectively) were prepared, and their photophysical properties were systematically investigated based on the measurements of steady-state absorption and fluorescence spectra, fluorescence lifetimes as well as transient absorption spectra. The ANIs efficiently fluoresced in solution, and the emission spectra appreciably shifted depending on the solvent polarity. 1ANI displayed only a slight fluorescence red-shift upon increasing the solvent polarity. In contrast, 5ANI and 6ANI showed marked positive solvatofluorochromism with large Stokes shifts displaying multicolour fluorescence; the fluorescence colours of 5ANI and 6ANI varied from violet-blue in hexane to orange-red in methanol. 5ANI and 6ANI, thus, serve as micro-environment responding fluorophores. In methanol, the intensity of the fluorescence emission band of 5ANI and 6ANI significantly reduced. Based on the fluorescence quantum yields and lifetimes, and transient absorption measurements, it has been revealed that internal conversion from the S-1 state of ANIs to the ground state was accelerated by the protic medium, resulting in a reduction in their fluorescence efficiency, while intersystem crossing from the S1 state to a triplet state was not responsible for the decrease of fluorescence intensity.

DOI： 10.1039/c6pp00048g

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Efficient Synthetic Photocyclization for Phenacenes Using a Continuous Flow Reactor 査読

Hideki Okamoto, Takamitsu Takane, Shin Gohda, Yoshihiro Kubozono, Kaori Sato, Minoru Yamaji, Kyosuke Satake

CHEMISTRY LETTERS   43 ( 7 )   994 - 996   2014年7月

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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  

The continuous flow reaction technique has been applied to the photocyclization of 1,2-diarylethenes, the so-called Mallory reaction, to afford phenacenes in high chemical yields and efficiencies (114-288 mg h(-1)). The present technique will allow us to produce several grams of phenacenes at a time.

DOI： 10.1246/cl.140182

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An Extended Phenacene-type Molecule, [8] Phenacene: Synthesis and Transistor Application 査読

Hideki Okamoto, Ritsuko Eguchi, Shino Hamao, Hidenori Goto, Kazuma Gotoh, Yusuke Sakai, Masanari Izumi, Yutaka Takaguchi, Shin Gohda, Yoshihiro Kubozono

SCIENTIFIC REPORTS   4   5330-1-5330-8   2014年6月

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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）   出版者・発行元：NATURE PUBLISHING GROUP  

A new phenacene-type molecule, [8] phenacene, which is an extended zigzag chain of coplanar fused benzene rings, has been synthesised for use in an organic field-effect transistor (FET). The molecule consists of a phenacene core of eight benzene rings, which has a lengthy pi-conjugated system. The structure was verified by elemental analysis, solid-state NMR, X-ray diffraction (XRD) pattern, absorption spectrum and photoelectron yield spectroscopy (PYS). This type of molecule is quite interesting, not only as pure chemistry but also for its potential electronics applications. Here we report the physical properties of [8] phenacene and its FET application. An [8] phenacene thin-film FET fabricated with an SiO2 gate dielectric showed clear p-channel characteristics. The highest m achieved in an [8] phenacene thin-film FET with an SiO2 gate dielectric is 1.74 cm(2) V-1 s(-1), demonstrating excellent FET characteristics; the average mu was evaluated as 1.2(3) cm(2) V-1 s(-1). The mu value in the [8] phenacene electric-double-layer FET reached 16.4 cm(2) V-1 s(-1), which is the highest reported in EDL FETs based on phenacene-type molecules; the average m was evaluated as 8(5) cm(2) V-1 s(-1). The mu values recorded in this study show that [8] phenacene is a promising molecule for transistor applications.

DOI： 10.1038/srep05330

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Transistor application of alkyl-substituted picene 査読

Hideki Okamoto, Shino Hamao, Hidenori Goto, Yusuke Sakai, Masanari Izumi, Shin Gohda, Yoshihiro Kubozono, Ritsuko Eguchi

SCIENTIFIC REPORTS   4   5408-1-5408-6   2014年5月

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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  

Field-effect transistors (FETs) were fabricated with a thin film of 3,10-ditetradecylpicene, picene-(C14H29)(2), formed using either a thermal deposition or a deposition from solution (solution process). All FETs showed p-channel normally-off characteristics. The field-effect mobility, m, in a picene-(C14H29)(2) thin-film FET with PbZr0.52Ti0.48O3 (PZT) gate dielectric reached similar to 21 cm(2) V-1 s(-1), which is the highest mu value recorded for organic thin-film FETs; the averagem mu value (<mu >) evaluated from twelve FET devices was 14(4) cm(2)V(-1) s(-1). The, m. values for picene-(C14H29)(2) thin- film FETs with other gate dielectrics such as SiO2, Ta2O5, ZrO2 and HfO2 were greater than 5 cm(2) V-1 s(-1), and the lowest absolute threshold voltage, vertical bar V-th vertical bar, (5.2 V) was recorded with a PZT gate dielectric; the average jVthj for PZT gate dielectric is 7(1) V. The solution-processed picene-(C14H29)(2) FET was also fabricated with an SiO2 gate dielectric, yielding mu = 3.4 x 10(-2) cm(2) V-1 s(-1). These results verify the effectiveness of picene-(C14H29)(2) for electronics applications.

DOI： 10.1038/srep05048

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S-2 fluorescence from picene vapor 査読

Takao Itoh, Minoru Yamaji, Hideki Okamoto

CHEMICAL PHYSICS LETTERS   570   26 - 28   2013年5月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Fluorescence, fluorescence excitation and absorption spectra of picene have been measured in the vapor phase. It is shown that picene vapor exhibits weak fluorescence from the S-2(pi, pi*) state in addition to strong S-1(pi, pi*) fluorescence. The S-2/S-1 fluorescence yield ratio is evaluated to be approximately 1.3 x 10(-2) following the excitation into the S-3 state. It is shown that the relative S-2 fluorescence quantum yield increases with increasing excitation energy, while the S-1 fluorescence yield is nearly invariant. Mechanism of the appearance of the S-2 fluorescence of picene vapor is discussed. (c) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2013.03.055

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Photochemical synthesis and electronic spectra of fulminene ([6]phenacene) 査読

Hideki Okamoto, Minoru Yamaji, Shin Gohda, Kaori Sato, Hisako Sugino, Kyosuke Satake

RESEARCH ON CHEMICAL INTERMEDIATES   39 ( 1 )   147 - 159   2013年1月

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担当区分：筆頭著者,　責任著者   記述言語：英語   出版者・発行元：SPRINGER  

Facile synthesis of fulminene ([6]phenacene) was achieved through the Mallory reaction of 1-(1-naphthyl)-2-(1-phenanthryl)ethene or the 9-fluorenone-sensitized photo-ring-closure of 1-(1-naphthyl)-2-(1-phenanthryl)ethane. The electronic spectral properties of fulminene were investigated for the first time using photoluminescence as well as transient absorption spectroscopy. The spectral features were compared with those of a series of lower phenacene homologs such as phenanthrene ([3]phenacene), chrysene ([4]phenacene), and picene ([5]phenacene). For the [n]phenacene series, both the fluorescence and phosphorescence bands linearly red-shifted with an increase in the number of the benzene rings (n). Trends in the energy levels of the excited singlet (E (S)) and the triplet (E (T)) states were expressed as E (s) = -2.6n + 89.1 (kcal mol(-1)) and E (T) = -1.8n + 66.2 (kcal mol(-1)), respectively. In the case of fulminene, laser flash photolysis displayed a transient spectrum with an absorption maximum (lambda (max) (T-T) ) at 675 nm, which was assigned as the triplet fulminene excited state. The lambda (max) (T-T) values for the [n]phenacene series showed a linear correlation as a function of the ring number n, given by an equation, lambda (max) (T-T) = 60n + 318 (nm).

DOI： 10.1007/s11164-012-0639-1

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Fabrication of high performance/highly functional field-effect transistor devices based on [6]phenacene thin films 査読

Ritsuko Eguchi, Xuexia He, Shino Hamao, Hidenori Goto, Hideki Okamoto, Shin Gohda, Kaori Sato, Yoshihiro Kubozono

PHYSICAL CHEMISTRY CHEMICAL PHYSICS   15 ( 47 )   20611 - 20617   2013年

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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) based on [6]phenacene thin films were fabricated with SiO2 and parylene gate dielectrics. These FET devices exhibit field-effect mobility in the saturation regime as high as 7.4 cm(2) V-1 s(-1), which is one of the highest reported values for organic thin-film FETs. The two- and four-probe mobilities in the linear regime display nearly similar values, suggesting negligible contact resistance at 300 K. FET characteristics were investigated using two-probe and four-probe measurement modes at 50-300 K. The two-probe mobility of the saturation regime can be explained by the multiple shallow trap and release model, while the intrinsic mobility obtained by the four-probe measurement in the linear regime is better explained by the phenomenon of transport with charge carrier scattering at low temperatures. The FET device fabricated with a parylene gate dielectric on polyethylene terephthalate possesses both transparency and flexibility, implying feasibility of practical application of [6] phenacene FETs in flexible/transparent electronics. N-channel FET characteristics were also achieved in the [6] phenacene thin-film FETs using metals that possess a small work function for use as source/drain electrodes.

DOI： 10.1039/c3cp53598c

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Facile Synthesis of Picene from 1,2-Di(1-naphthyl)ethane by 9-Fluorenone-Sensitized Photolysis 査読

Hideki Okamoto, Minoru Yamaji, Shin Gohda, Yoshihiro Kubozono, Noriko Komura, Kaori Sato, Hisako Sugino, Kyosuke Satake

ORGANIC LETTERS   13 ( 10 )   2758 - 2761   2011年5月

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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）   出版者・発行元：AMER CHEMICAL SOC  

A facile formation of picene was achieved by photosensitization of 1,2-di(1-naphthyl)ethane using 9-fluorenone as a sensitizer. This sensitized photoreaction is the first photochemical cyclization of ethylene-bridged naphthalene moieties to afford the picene skeleton. 5,8-Dibromopicene, prepared by this procedure using 1,2-di[1-(4-bromonaphthyl)]ethane as the substrate, was readily converted to novel functionalized picenes by conventional substitution and cross-coupling reactions.

DOI： 10.1021/ol200874q

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Superconductivity in alkali-metal-doped picene 査読

Ryoji Mitsuhashi, Yuta Suzuki, Yusuke Yamanari, Hiroki Mitamura, Takashi Kambe, Naoshi Ikeda, Hideki Okamoto, Akihiko Fujiwara, Minoru Yamaji, Naoko Kawasaki, Yutaka Maniwa, Yoshihiro Kubozono

NATURE   464 ( 7285 )   76 - 79   2010年3月

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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  

Efforts to identify and develop new superconducting materials continue apace, motivated by both fundamental science and the prospects for application. For example, several new superconducting material systems have been developed in the recent past, including calcium-intercalated graphite compounds(1), boron-doped diamond(2) and-most prominently-iron arsenides such as LaO(1-x)F(x)FeAs (ref. 3). In the case of organic superconductors, however, no new material system with a high superconducting transition temperature (T(c)) has been discovered in the past decade. Here we report that intercalating an alkali metal into picene, a wide-bandgap semiconducting solid hydrocarbon, produces metallic behaviour and superconductivity. Solid potassium-intercalated picene (K(x)picene) shows T(c) values of 7K and 18 K, depending on the metal content. The drop of magnetization in Kxpicene solids at the transition temperature is sharp (<2 K), similar to the behaviour of Ca-intercalated graphite(1). The Tc of 18K is comparable to that of K-intercalated C(60) (ref. 4). This discovery of superconductivity in K(x)picene shows that organic hydrocarbons are promising candidates for improved T(c) values.

DOI： 10.1038/nature08859

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Air-assisted high-performance field-effect transistor with thin films of picene 査読

Hideki Okamoto, Naoko Kawasaki, Yumiko Kaji, Yoshihiro Kubozono, Akihiko Fujiwara, Minoru Yamaji

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   130 ( 32 )   10470 - +   2008年8月

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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）   出版者・発行元：AMER CHEMICAL SOC  

A field-effect transistor (FET) with thin films of picene has been fabricated on SiO(2) gate dielectric. The FET showed p-channel enhancement-type FET characteristics with the field-effect mobility, mu, of 1.1 cm(2) V(-1) s(-1) and the on-off ratio of >10(5). This excellent device performance was realized under atmospheric conditions. The p increased with an increase in temperature, and the FET performance was improved by exposure to air or O(2) for a long time. This result implies that this device is an air (O(2))-assisted FET. The FET characteristics are discussed on the basis of structural topography and the energy diagram of picene thin films.

DOI： 10.1021/ja803291a

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Fluorescence response of a 4-trifluoroacetylaminophthalimide to iodide ions upon 254 nm irradiation in MeCN 査読

Hideki Okamoto, Hiroyuki Konishi, Mami Kohno, Kyosuke Satake

ORGANIC LETTERS   10 ( 14 )   3125 - 3128   2008年7月

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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）   出版者・発行元：AMER CHEMICAL SOC  

The title trifluoroacetylaminophthalimide derivative produced a violet fluorescence (lambda(FL)(max) 392 nm) in MeCN, and it displayed a green emission (lambda(FL)(max) 506 nm) after irradiation at 254 nm in the presence of iodide ions. The corresponding amidate ion of the trifluoroacetamide was identified as the green fluorescence emitter. The deprotonation reaction may be caused by proton-abstracting solvated electrons generated by a photochemical charge-transfer-to-solvent process from I(-) to MeCN.

DOI： 10.1021/ol801184x

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Photoreaction of a 2,11-diaza[3.3]paracyclophane derivative: Formation of octahedrane by photochemical dimerization of benzene 査読

Hideki Okamoto, Kyosuke Satake, Hiroyuki Ishida, Masaru Kimura

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   128 ( 51 )   16508 - 16509   2006年12月

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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）   出版者・発行元：AMER CHEMICAL SOC  

DOI： 10.1021/ja067350r

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Triplet-sensitized photolysis of the photoisomer of a 2,11-diaza[3,3](9,10)anthracenoparacyclophane: An adiabatic cycloreversion and a [2 pi a+2 pi a+2 sigma s] rearrangement in a triplet state of the biplanophane system 査読

H Okamoto, M Yamaji, K Satake, S Tobita, M Kimura

JOURNAL OF ORGANIC CHEMISTRY   69 ( 23 )   7860 - 7868   2004年11月

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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）   出版者・発行元：AMER CHEMICAL SOC  

The triplet-sensitized photoreactions of the title biplanophane system 6, the photoisomer of a 2,11diaza[3,31(9,10)anthracenoparacyclophane derivative 5, were investigated by stationary and laserflash photolyses using xanthone (XT) and benzophenone (BP) as triplet sensitizers. Vaen photoisomer 6 underwent XT-sensitized irradiation, a triplet cyclophane 5 and a novel polycyclic product 7 were obtained via an adiabatic cycloreversion and a formal [2pia + 2 pia + 2sigmas] rearrangement, respectively. The maximum quantum yield for the formation of cyclophane 5 (0.69) and the upper-limit efficiency for the formation of polycycle 7 (0.31) were determined by laser photolysis techniques. For BP-sensitized photolysis of photoisomer 6, oxetane 8, in addition to triplet cyclophane 5 and polycycle 7, was formed by a Paterno-Biichi reaction. The quenching rate constant (k(q)) of triplet BP by photoisomer 6 (3.4 x 10(8) dm(3) Mol(-1) s(-1)) was found to be 1 order of magnitude smaller than that for XT (5.0 x 10(9) dm(3) mol(-1) s(-1)). On the basis of the relationship between k(q) and the triplet donor-acceptor energy gap, the triplet energy level of photoisomer 6 was estimated to be similar to71 kcal mol(-1). The photochemical and the photophysical processes involved in the sensitized photolyses are summarized in an energetic reaction diagram and discussed in detail.

DOI： 10.1021/jo048757m

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Highly emissive and robust diarylethene fluorophore incorporating imide-fused phenanthryl moieties 査読

Keito Nose, Minoru Yamaji, Tadashi Mori, Fumito Tani, Kenta Goto, Hideki Okamoto

Chemistry Letters   54 ( 5 )   2025年5月

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担当区分：責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

The fluorescence properties and photostabilities of (E)-diarylethenes (DPEs), featuring two 3-phenanthryl moieties, were investigated. Pristine (E)-di-1,2-(3-phenanthryl)ethene and its ester derivative, respectively referred to as DPE-H and DPE-E, exhibited blue fluorescence. However, they underwent a two-step photoreaction sequence that yielded [7]helicenes, resulting in a gradual reduction of the fluorescence intensity. In contrast, the imide-fused derivative DPE-I displayed intense green fluorescence and it was unexpectedly photostable in solution, maintaining its highly efficient fluorescent nature even after prolonged light exposure. DPE-I, thus, provides a new type of highly efficient and robust diarylethene fluorophore.

DOI： 10.1093/chemle/upaf091

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Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra 査読

Yuuki Ishii, Minoru Yamaji, Fumito Tani, Kenta Goto, Yoshihiro Kubozono, Hideki Okamoto

Beilstein Journal of Organic Chemistry   21   670 - 679   2025年3月

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担当区分：責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Beilstein Institut  

[n]Phenacenes ([n] = 5–7), octafluorinated at the terminal benzene rings (F₈-phenacenes: F₈PIC, F₈FUL, and F₈7PHEN), were photochemically synthesized, and their electronic spectra were investigated to reveal the effects of the fluorination on the electronic features of phenacene molecules. F₈-Phenacenes were conveniently synthesized by the Mallory photoreaction of the corresponding fluorinated diarylethenes as the key step. Upon fluorination on the phenacene cores, the absorption and fluorescence bands of the F₈-phenacenes in CHCl₃ systematically red-shifted by ca. 3–5 nm compared to those of the corresponding parent phenacenes. The vibrational progressions of the absorption and fluorescence bands were little affected by the fluorination in the solution phase. In the solid state, the absorption band of F₈-phenacenes appeared in the similar wavelength region for the corresponding parent phenacenes whereas their fluorescence bands markedly red-shifted and broadened. These observations suggest that the intermolecular interactions of excited-state F₈-phenacene molecules are significantly different from those of the corresponding parent molecules, most likely due to different crystalline packing motifs.

DOI： 10.3762/bjoc.21.53

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その他リンク： https://www.beilstein-journals.org/bjoc/content/pdf/1860-5397-21-53.pdf

Biosensor Application of CMOS Inverter and Ring Oscillator with Organic Field-Effect Transistors 査読

Masaki Utsumi, Akihiko Fujiwara, Hidenori Goto, Hideki Okamoto, Nobuyuki Takeyasu, Yasunori Saitoh, Michihiro Suga, Yuichiro Takahashi, Hiroyuki Imanaka, Hiroki Taniguchi, Shintaro Yasui, Ritsuko Eguchi, Yoshihiro Kubozono

ACS Applied Electronic Materials   2025年2月

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掲載種別：研究論文（学術雑誌）   出版者・発行元：American Chemical Society (ACS)  

DOI： 10.1021/acsaelm.4c02031

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Solid-State Photoluminescence of Diphenylnaphthalenes Studied by Photophysical Measurements and Crystallographic Analysis 査読 国際誌

29 ( 24 )   5941   2024年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/molecules29245941

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Roto‐Cyclization of 4‐Bromopicene in On‐Surface Synthesis 査読 国際共著 国際誌

19 ( 22 )   e202400620   2024年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/asia.202400620

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Vertical Intermolecular Electronic Communication in Dibenzo[6]phenacene on Ag(111) 査読 国際共著 国際誌

128 ( 33 )   14065 - 14074   2024年8月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.jpcc.4c03476

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Intramolecular [π4s + π4s] photocycloaddition of carbon- and nitrogen-bridged [32](1,4)naphthalenophanes 査読 国際誌

Yukiko Oguma, Masanori Yamamoto, Yukinari Sunatsuki, Hiromi Ota, Minoru Yamaji, Hideki Okamoto

Photochemical & Photobiological Sciences   23 ( 8 )   1509 - 1519   2024年7月

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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：Springer Science and Business Media LLC  

Abstract

[3₂](1,4)Naphthalenophanes, bearing carbon-bridge chains (syn- and anti-NPs) and nitrogen-bridge chains (syn- and anti-ANPs), were synthesized, and their X-ray structures and photoreactions were investigated. The intramolecular separation distance between the naphthalene cores for ANPs was shorter than that for NPs, suggesting that intramolecular interactions between the naphthalene rings  were more efficient for ANPs compared to NPs. Upon photoirradiation at 300 nm, anti-NP, syn-ANP and anti-ANP produced the corresponding intramolecular [π4s + π4s] cycloadducts, whereas syn-NP gave an unidentified complex product mixture. Quantum yields for the photo-consumption (Φ_PC) of NPs and ANPs were evaluated to quantitatively compare their photoreactivity. The Φ_PC values of ANPs were approximately two-fold higher than those of ANPs.Noteworthily, the Φ_PC value of syn-ANP was estimated to be unity. Based on these results we discuss the effects of the alignments of the naphthalene cores (antivs. syn) and the bridging elements (C-bridge vs. N-bridge) on the photoreaction efficiencies of [3₂](1,4)naphthalenophanes.

DOI： 10.1007/s43630-024-00610-w

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その他リンク： https://link.springer.com/article/10.1007/s43630-024-00610-w/fulltext.html

Photochemical synthesis and solvatochromic fluorescence behavior of imide-fused phenace 査読 国際誌

452   115613 - 115613   2024年7月

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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）  

DOI： 10.1016/j.jphotochem.2024.115613

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Coulomb Scattering Controlled by Ionized Molecules Adsorbed on Graphene 査読 国際誌

128 ( 1 )   467 - 473   2023年12月

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掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acs.jpcc.3c06294

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Star-burst polycyclic aromatic hydrocarbons prepared by multi-photocyclization and the photophysical features 査読 国際誌

Minoru Yamaji, Hideki Okamoto

Journal of Photochemistry and Photobiology A: Chemistry   436   114387 - 114387   2023年3月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.jphotochem.2022.114387

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Solvent-dependent fluorescence behaviour of imide-fused [n]phenacenes (n = 3, 5, 7) 査読 国際誌

13 ( 6 )   4096 - 4101   2023年

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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）  

DOI： 10.1039/d2ra07771j

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Charge Transport Capabilities of Dibenzo[n]phenacenes (n = 5–7): Influence of Trap States and Molecular Packing 査読

Yanting Zhang, Shino Hamao, Hidenori Goto, Yoshihiro Kubozono, Hideki Okamoto, Kunihisa Sugimoto, Nobuhiro Yasuda, Akihiko Fujiwara, Ritsuko Eguchi

The Journal of Physical Chemistry C   126 ( 44 )   18849 - 18854   2022年10月

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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 (ACS)  

DOI： 10.1021/acs.jpcc.2c04879

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Evaluation of Effective Field-Effect Mobility in Thin-Film and Single-Crystal Transistors for Revisiting Various Phenacene-Type Molecules 査読 国際誌

Yanting Zhang, Ritsuko Eguchi, Shino Hamao, Hideki Okamoto, Hidenori Goto, Yoshihiro Kubozono

ACS OMEGA   7 ( 6 )   5495 - 5501   2022年2月

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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 magnitude of the field-effect mobility mu of organic thin-film and single-crystal field-effect transistors (FETs) has been over-estimated in certain recent studies. These reports set alarm bells ringing in the research field of organic electronics. Herein, we report a precise evaluation of the mu values using the effective field-effect mobility, mu(eff), a new indicator that is recently designed to prevent the FET performance of thin-film and single-crystal FETs based on various phenacene molecules from being overestimated. The transfer curves of a range of FETs based on phenacene are carefully categorized on the basis of a previous report. The exact evaluation of the value of mu(eff) depends on the exact classification of each transfer curve. The transfer curves of all our phenacene FETs could be successfully classified based on the method indicated in the aforementioned report, which made it possible to evaluate the exact value of mu(eff) for each FET. The FET performance based on the values of mu(eff) obtained in this study is discussed in detail. In particular, the mu(eff) values of single-crystal FETs are almost consistent with the mu values that were reported previously, but the mu(eff) values of thin-film FETs were much lower than those previously reported for mu, owing to a high absolute threshold voltage, vertical bar V-th vertical bar. The increase in the field-effect mobility as a function of the number of benzene rings, which was previously demonstrated based on the mu values of single-crystal FETs with phenacene molecules, is well reproduced from the mu(eff) values. The FET performance is discussed based on the newly evaluated mu(eff) values, and the future prospects of using phenacene molecules in FET devices are demonstrated.

DOI： 10.1021/acsomega.1c06932

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Fabrication and characterization of thin-film field-effect transistors with alkyl-phenyl[n]phenacenes (n = 4–6) 査読

Yanting Zhang, Ritsuko Eguchi, Hideki Okamoto, Kenta Goto, Fumito Tani, Minoru Yamaji, Hidenori Goto, Yoshihiro Kubozono

Journal of Materials Chemistry C   10 ( 43 )   16309 - 16320   2022年

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Royal Society of Chemistry (RSC)  

3-Decyl-10-phenyl[5]phenacene (PhC10-PIC) molecule shows good FET characteristics in case of using ZrO₂ gate dielectric, owing to strong fastener effect and large π-overlap.

DOI： 10.1039/d2tc03383f

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Synthesis of 2,3-Anthracenedicarboxylic-acid-derived Fluorophore and Chemiluminophore Incorporating Dipicolylaminomethyl Receptors, and Their Luminescence Responses to Metal Ions 査読

Hideki Okamoto, Naomi Yamazaki, Ayako Matsui, Kyosuke Satake

HETEROCYCLES   104 ( 9 )   1614 - 1614   2022年

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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）   出版者・発行元：The Japan Institute of Heterocyclic Chemistry  

DOI： 10.3987/com-22-14703

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Solid-state photoluminescence of biaryls: Relationship between photophysical feature and crystal structure 査読 国際誌

Minoru Yamaji, Hideki Okamoto, Kenta Goto, Fumito Tani

Journal of Photochemistry and Photobiology A: Chemistry   421   113518 - 113518   2021年12月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jphotochem.2021.113518

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Fabrication of ring oscillators using organic molecules of phenacene and perylenedicarboximide 査読 国際共著 国際誌

Niko Fioravanti, Luca Pierantoni, Davide Mencarelli, Claudio Turchetti, Shino Hamao, Hideki Okamoto, Hidenori Goto, Ritsuko Eguchi, Akihiko Fujiwara, Yoshihiro Kubozono

RSC Advances   11 ( 13 )   7538 - 7551   2021年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/d1ra00511a

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Synthesis and photophysical properties of blue-color emitting compounds having multi N-methylanthranillic (MANT) chromophore 査読 国際誌

Minoru Yamaji, Kanae Sano, Hideki Okamoto, Ichiro Matsuo

Journal of Photochemistry and Photobiology A: Chemistry   400   112650 - 112650   2020年9月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jphotochem.2020.112650

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Facile synthesis of picenes incorporating imide moieties at both edges of the molecule and their application to n-channel field-effect transistors 査読 国際誌

Yuxin Guo, Kaito Yoshioka, Shino Hamao, Yoshihiro Kubozono, Fumito Tani, Kenta Goto, Hideki Okamoto

RSC Advances   10 ( 52 )   31547 - 31552   2020年

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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）  

DOI： 10.1039/d0ra06629j

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Low-voltage organic thin-film transistors based on [n]phenacenes 査読 国際共著 国際誌

Afra Al Ruzaiqi, Hideki Okamoto, Yoshihiro Kubozono, Ute Zschieschang, Hagen Klauk, Peter Baran, Helena Gleskova

Organic Electronics   73   286 - 291   2019年10月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.orgel.2019.06.021

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Fluorescence properties of amido-substituted 2,3-naphthalimides: Excited-state intramolecular proton transfer (ESIPT) fluorescence and responses to Ca2+ ions 査読 国際誌

Lei Wang, Mayu Fujii, Misa Namba, Minoru Yamaji, Hideki Okamoto

Tetrahedron Letters   60 ( 43 )   151189 - 151189   2019年10月

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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）  

DOI： 10.1016/j.tetlet.2019.151189

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Distinctive effects on fluorescence quantum yields of 4-substituted N-methylphthalimides by inclusion complexation with β-cyclodextrins 査読

Yoshimi Sueishi, Yuki Matsumoto, Junko Sohama, Yoshihiro Osawa, Hideki Okamoto

Journal of Inclusion Phenomena and Macrocyclic Chemistry   93 ( 3-4 )   275 - 281   2019年4月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s10847-018-00877-4

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その他リンク： http://link.springer.com/article/10.1007/s10847-018-00877-4/fulltext.html

Transistor Application and Intercalation Chemistry of π-Conjugated Hydrocarbon Molecules

Yoshihiro Kubozono, Shino Hamao, Takahiro Mikami, Yuma Shimo, Yasuhiko Hayashi, Hideki Okamoto

Physics and Chemistry of Carbon-Based Materials   229 - 252   2019年

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掲載種別：論文集(書籍)内論文   出版者・発行元：Springer Singapore  

DOI： 10.1007/978-981-13-3417-7_8

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Blue fluorescence from N,O-coordinated BF2 complexes having aromatic chromophores in solution and the solid state 査読 国際誌

Minoru Yamaji, Kazuhiro Tomonari, Keisuke Ikuma, Kenta Goto, Fumito Tani, Hideki Okamoto

Photochemical & Photobiological Sciences   18 ( 12 )   2884 - 2892   2019年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c9pp00410f

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Fabrication of flexible high-performance organic field-effect transistors using phenacene molecules and their application toward flexible CMOS inverters 査読 国際共著 国際誌

Emanuela Pompei, Claudio Turchetti, Shino Hamao, Akari Miura, Hidenori Goto, Hideki Okamoto, Akihiko Fujiwara, Ritsuko Eguchi, Yoshihiro Kubozono

Journal of Materials Chemistry C   7 ( 20 )   6022 - 6033   2019年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c8tc05824e

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Photophysical features of naphthols having esters, formyl and acetyl groups and the difluoroboronated complex in solution and the solid state 査読 国際誌

Minoru Yamaji, Hideki Okamoto

Journal of Photochemistry and Photobiology A: Chemistry   360   204 - 209   2018年6月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.jphotochem.2018.04.017

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Synthesis of isomeric coumarin-fluorene hybrids by photocyclization and the photophysical features 査読 国際誌

Minoru Yamaji, Hideki Okamoto, Kenta Goto, Shin-ichiro Kato, Fumito Tani, Yosuke Nakamura

Tetrahedron Letters   59 ( 13 )   1216 - 1219   2018年3月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.tetlet.2018.02.033

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Excited-state intramolecular proton transfer (ESIPT) fluorescence from 3-amidophthalimides displaying RGBY emission in the solid state 査読

Hideki Okamoto, Kazumasa Itani, Minoru Yamaji, Hiroyuki Konishi, Hiromi Ota

Tetrahedron Letters   59 ( 4 )   388 - 391   2018年1月

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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）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.tetlet.2017.12.049

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Fluorescence behaviour of 2-, 3- and 4-amino-1,8-naphthalimides: effects of the substitution positions of the amino functionality on the photophysical properties 査読 国際誌

Lei Wang, Mayu Fujii, Minoru Yamaji, Hideki Okamoto

Photochemical & Photobiological Sciences   17 ( 10 )   1319 - 1328   2018年

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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：Springer Science and Business Media LLC  

<p>2-Amino-1,8-naphthalimide showed blue fluorescence independent of the microenvironment of the solvents whereas the corresponding 3- and 4-amino derivatives displayed marked positive solvatofluorochromism.</p>

DOI： 10.1039/c8pp00302e

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Blue Fluorescence from BF2 Complexes of N,O-Benzamide Ligands: Synthesis, Structure, and Photophysical Properties 査読

Minoru Yamaji, Shin-ichiro Kato, Kazuhiro Tomonari, Michitaka Mamiya, Kenta Goto, Hideki Okamoto, Yosuke Nakamura, Fumito Tani

Inorganic Chemistry   56 ( 20 )   12514 - 12519   2017年10月

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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 (ACS)  

DOI： 10.1021/acs.inorgchem.7b02013

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Synthesis, structure, and photoreactions of fluorinated 2,11-diaza[32]paracyclophane: Photochemical formation of cage-diene type benzene dimer 査読

Hideki Okamoto, Tetsuya Kozai, Zenji Okabayashi, Teruo Shinmyozu, Hiromi Ota, Kiichi Amimoto, Kyosuke Satake

Journal of Physical Organic Chemistry   30 ( 9 )   e3726 - e3726   2017年9月

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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）   出版者・発行元：Wiley  

DOI： 10.1002/poc.3726

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Convenient Phenacene Synthesis by Sequentially Performed Wittig Reaction and Mallory Photocyclization Using Continuous-Flow Techniques 査読

Hideki Okamoto, Haruhiko Takahashi, Takamitsu Takane, Yasuhiro Nishiyama, Kiyomi Kakiuchi, Shin Gohda, Minoru Yamaji

SYNTHESIS-STUTTGART   49 ( 13 )   2949 - 2957   2017年7月

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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）   出版者・発行元：GEORG THIEME VERLAG KG  

Various phenacenes possessing chrysene, picene, and fulminene frameworks were prepared by using a continuous-flow synthetic protocol in which Wittig reaction affording diarylethenes and their Mallory photocyclization producing phenacene skeletons were sequentially performed. The Wittig reaction solution, containing the diarylethene obtained from an arylaldehyde and an arylmethyltriphenylphosphonium salt, was mixed with an iodine solution in the flow system and, subsequently, the solution was subjected to the photoreaction. Desired phenacenes were obtained with high to moderate chemical yield. For the present protocol, isolation of the intermediary diarylethene, which is the key precursor of the phenacene, is unnecessary. The approach provides a convenient method to supply a variety of phenacene samples, which are needed for initial systematic surveys in material science.

DOI： 10.1055/s-0036-1588775

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Adsorption of Phenacenes on a Metallic Substrate: Revisited 査読

Song-Wen Chen, I-Chen Sang, Hideki Okamoto, Germar Hoffmann

The Journal of Physical Chemistry C   121 ( 21 )   11390 - 11398   2017年6月

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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 (ACS)  

DOI： 10.1021/acs.jpcc.7b01806

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Systematic investigations on fused π-system compounds of seven benzene rings prepared by photocyclization of diphenanthrylethenes 査読

Shota Fujino, Minoru Yamaji, Hideki Okamoto, Toshiki Mutai, Isao Yoshikawa, Hirohiko Houjou, Fumito Tani

Photochemical and Photobiological Sciences   16 ( 6 )   925 - 934   2017年6月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c7pp00040e

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Photochemical synthesis and photophysical properties of coumarins bearing extended polyaromatic rings studied by emission and transient absorption measurements 査読

Minoru Yamaji, Yuma Hakoda, Hideki Okamoto, Fumito Tani

PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES   16 ( 4 )   555 - 563   2017年4月

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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 prepared a variety of coumarin derivatives having expanded pi-electron systems along the direction crossing the C-3-C-4 bond of the coumarin skeleton via a photochemical cyclization process and investigated their photophysical features as a function of the number (n) of the added benzene rings based on emission and transient absorption measurements. Upon increasing n, the fluorescence quantum yields of the pi-extended coumarins increased. Expanding the p-electron system on the C-3-C-4 bond of the coumarin skeleton was found to be efficient for increasing the fluorescence ability more than that on the C-7-C-8 bond. Introducing the methoxy group at the 7-position was also efficient for enhancing the fluorescence quantum yield and rate of the expanded coumarins. The non-radiative process from the fluorescence state was not substantially influenced by the expanded pi-electron system. The competitive process with the fluorescence was found to be intersystem crossing to the triplet state based on the observations of the triplet-triplet absorption. The effects of the expanded pi-electron systems on the fluorescence ability were investigated with the aid of TD-DFT calculations.

DOI： 10.1039/c6pp00399k

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Chemical analysis of superconducting phase in K-doped picene 査読

Takashi Kambe, Saki Nishiyama, Huyen L. T. Nguyen, Takahiro Terao, Masanari Izumi, Yusuke Sakai, Lu Zheng, Hidenori Goto, Yugo Itoh, Taiki Onji, Tatsuo C. Kobayashi, Hisako Sugino, Shin Gohda, Hideki Okamoto, Yoshihiro Kubozono

JOURNAL OF PHYSICS-CONDENSED MATTER   28 ( 44 )   2016年11月

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

Potassium-doped picene (K(3.0)picene) with a superconducting transition temperature (TC) as high as 14 K at ambient pressure has been prepared using an annealing technique. The shielding fraction of this sample was 5.4% at 0 GPa. The TC showed a positive pressure-dependence and reached 19 K at 1.13 GPa. The shielding fraction also reached 18.5%. To investigate the chemical composition and the state of the picene skeleton in the superconducting sample, we used energy-dispersive x-ray (EDX) spectroscopy, MALDI-time-of-flight (MALDI-TOF) mass spectroscopy and x-ray diffraction (XRD). Both EDX and MALDI-TOF indicated no contamination with materials other than K-doped picene or K-doped picene fragments, and supported the preservation of the picene skeleton. However, it was also found that a magnetic K-doped picene sample consisted mainly of picene fragments or K-doped picene fragments. Thus, removal of the component contributing the magnetic quality to a superconducting sample should enhance the volume fraction.

DOI： 10.1088/0953-8984/28/44/444001

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Recent progress on carbon-based superconductors 査読

Yoshihiro Kubozono, Ritsuko Eguchi, Hidenori Goto, Shino Hamao, Takashi Kambe, Takahiro Terao, Saki Nishiyama, Lu Zheng, Xiao Miao, Hideki Okamoto

Journal of Physics: Condensed Matter   28 ( 33 )   334001 - 334001   2016年8月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0953-8984/28/33/334001

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その他リンク： http://stacks.iop.org/0953-8984/28/i=33/a=334001?key=crossref.cedda9374837be0f2e3c82a674e5a7ac

Synthesis and photophysical properties of difluoroboronated β-diketones with the fluorene moiety that have high fluorescence quantum yields 査読

Yurie Suwa, Minoru Yamaji, Hideki Okamoto

Tetrahedron Letters   57 ( 15 )   1695 - 1698   2016年4月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.tetlet.2016.03.011

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Synthesis and transistor application of the extremely extended phenacene molecule, [9] phenacene 査読

Yuma Shimo, Takahiro Mikami, Shino Hamao, Hidenori Goto, Hideki Okamoto, Ritsuko Eguchi, Shin Gohda, Yasuhiko Hayashi, Yoshihiro Kubozono

SCIENTIFIC REPORTS   6   2016年2月

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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  

the widespread interest in the chemistry, physics and materials science of such molecules and their potential applications. In particular, extended phenacene molecules, consisting of coplanar fused benzene rings in a repeating W-shaped pattern have attracted much attention because field-effect transistors (FETs) using phenacene molecules show promisingly high performance. Until now, the most extended phenacene molecule available for transistors was [8] phenacene, with eight benzene rings, which showed very high FET performance. Here, we report the synthesis of a more extended phenacene molecule, [9] phenacene, with nine benzene rings. Our synthesis produced enough [9] phenacene to allow the characterization of its crystal and electronic structures, as well as the fabrication of FETs using thin-film and single-crystal [9] phenacene. The latter showed a field-effect mobility as high as 18 cm(2) V-1 s(-1), which is the highest mobility realized so far in organic single-crystal FETs.

DOI： 10.1038/srep21008

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Preparation and photophysical properties of fluorescent difluoroboronated β-diketones having phenanthrene moieties studied by emission and transient absorption measurements 査読

Michitaka Mamiya, Yurie Suwa, Hideki Okamoto, Minoru Yamaji

Photochemical and Photobiological Sciences   15 ( 2 )   278 - 286   2016年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c5pp00454c

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Photochemically-assisted synthesis and photophysical properties of difluoroboronated β-diketones with fused four-benzene-ring chromophores, chrysene and pyrene 査読

Michitaka Mamiya, Yurie Suwa, Hideki Okamoto, Minoru Yamaji

Photochemical and Photobiological Sciences   15 ( 7 )   928 - 936   2016年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c6pp00089d

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Photophysical and photochemical processes of excited singlet and triplet [3n]cyclophanes (n = 2–6) studied by emission measurements, steady-state and laser flash photolyses 査読

Minoru Yamaji, Hideki Okamoto, Yuhko Hakoshima, Teruo Shinmyozu

J. Phys. Chem. A   119 ( 10 )   1867 - 1874   2015年3月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/jp511105v

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Transistors fabricated using the single crystals of [8]phenacene 査読

Yuma Shimo, Takahiro Mikami, Hiroto T. Murakami, Shino Hamao, Hidenori Goto, Hideki Okamoto, Shin Gohda, Kaori Sato, Antonio Cassinese, Yasuhiko Hayashi, Yoshihiro Kubozono

JOURNAL OF MATERIALS CHEMISTRY C   3 ( 28 )   7370 - 7378   2015年

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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) with single crystals of a new phenacene-type molecule, [8]phenacene, were fabricated and characterized. This new molecule consists of a phenacene core of eight benzene rings, with an extended p-conjugated system, which was recently synthesized for use in an FET by our group. The FET characteristics of an [8]phenacene single-crystal FET with SiO2 gate dielectrics show typical p-channel properties with an average field-effect mobility, &lt;mu &gt;, as high as 3(2) cm(2) V-1 s(-1) in two-terminal measurement mode, which is a relatively high value for a p-channel single-crystal FET. The hmi was determined to be 6(2) cm(2) V-1 s(-1) in four-terminal measurement mode. Low-voltage operation was achieved with PbZr0.52Ti0.48O3 (PZT) as the gate dielectric, and an electric-double-layer (EDL) capacitor. The &lt;mu &gt; and average values of absolute threshold voltage, &lt;vertical bar V-th vertical bar &gt;, were 1.6(4) cm(2) V-1 s(-1) and 5(1) V, respectively, for PZT, and 4(2) x 10(-1) cm(2) V-1 s(-1) and 2.38(4) V, respectively, for the EDL capacitor; these values were evaluated in two-terminal measurement mode. The inverter circuit was fabricated using [8]phenacene and N, N'-1H, 1H-perfluorobutyldicyanoperylene-carboxydi-imide single-crystal FETs. This is the first logic gate circuit using phenacene molecules. Furthermore, the relationship between mu and the number of benzene rings was clarified based on this study and the previous studies on phenacene single-crystal FETs.

DOI： 10.1039/c5tc00960j

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Photochemical synthesis of diphenylphenanthrenes, and the photophysical properties studied by emission and transient absorption measurements 査読

Minoru Yamaji, Yuuma Hakoda, Ami Horimoto, Hideki Okamoto

Rapid communications in Photoscience   4   73 - 75   2014年

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Characteristics of [6]phenacene thin film field-effect transistor 査読

Noriko Komura, Hidenori Goto, Xuexia He, Hiroki Mitamura, Ritsuko Eguchi, Yumiko Kaji, Hideki Okamoto, Yasuyuki Sugawara, Shin Gohda, Kaori Sato, Yoshihiro Kubozono

APPLIED PHYSICS LETTERS   101 ( 8 )   2012年8月

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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 INST PHYSICS  

Transistor characteristics are studied for field-effect transistors (FETs) with thin films of [6]phenacene, which has six benzene rings and W-shape structure. The molecular alignment preferable for FET transport is found to be formed in [6]phenacene thin films. The transistor shows clear p-channel FET characteristics with field-effect mobility mu as high as 3.7 cm(2) V-1 s(-1). The similar O-2 sensing properties to picene FET are observed in [6]phenacene thin film FET. The bias stress properties are observed in [6]phenacene thin film FET. The pulse-voltage application suppresses the bias-stress effect and it enables a continuous O-2 sensing in [6]phenacene FET. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4747201]

DOI： 10.1063/1.4747201

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Unprecedented Temperature-dependent Formation of 3-and 7-Methyl-3H-azepine Derivatives by the Reaction of o-Nitrotoluene with Tributylphosphine in Nucleophilic Media 査読

Siti Mariyah Ulfa, Hideki Okamoto, Kyosuke Satake

CHEMISTRY LETTERS   41 ( 4 )   400 - 402   2012年4月

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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  

The reaction of o-methylphenylnitrene in the presence of alcohol and amine was expected to give isomeric pairs of 3- and 7-methyl-3H-azepine derivatives. The formation ratio between these isomers was found to be obviously influenced by reaction temperature, that is, reaction at 150 degrees C gave 7-methyl-3H-azepine derivative, however, it became minor under 70 degrees C in both media. The ratio between 3- and 7-methyl derivatives is explained by a scheme of kinetic- and thermodynamic-controlled product distribution from o-methylphenylnitrene to 3- and 7-methyldehydroazepine intermediates which are trapped by nucleophilic media to give 3- and 7-methyl-3H-azepine derivatives.

DOI： 10.1246/cl.2012.400

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Studies on interactions of excited cadmium and mercury atoms with secondary and tertiary alkyl- and silylamines in gas phase

Shunzo Yamamoto, Eriko Kainaga, Omar Ahmed, Hideki Okamoto, Yoshimi Sueishi

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY   228 ( 1 )   38 - 43   2012年1月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE SA  

The Cd(P-3(1))- and Hg(P-3(1))-photosensitized emissions of some secondary and tertiary alkyl- and silylamines have been investigated under conditions of steady illumination at 493 and 298 K, respectively. The emission bands were observed at around 440 nm in the cadmium-photosensitized reactions of these amines. In contrast, no appreciable emission bands were observed in the mercury-photosensitized reactions of these amines. However, upon addition of tert-butyl alcohol to the amine-mercury system, an emission band evolved at around 350 nm in the mercury-photosensitization. The peak-wavelengths for secondary and tertiary alkyl- and silylamines are slightly shorter than the values predicted from the correlations between the peak wavelength and the first ionization energy obtained in the cadmium- and mercury-photosensitized luminescence of ammonia and primary amines. The quenching efficiencies of the cadmium and mercury resonance lines by secondary alkyl- and silylamines are higher than those by tertiary alkyl- and silylamines. These observations suggest that the steric hindrance by the alkyl and silyl groups to the approach of the nitrogen atom in the amines to excited cadmium and mercury atoms seems to be an important factor for the stabilization of the exciplexes and the quenching of the resonance lines. The behavior of silylamines is similar to that of alkylamines in cadmium- and mercury-photosensitized reactions. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jphotochem.2011.11.010

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Fluorescence response of 3-trifluoroacetylaminophthalimide to Li+–I− ion pair induced by 254 nm photolysis in acetonitrile

Chem. Commun.   48 ( 17 )   2346 - 2348   2012年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/c2cc17502a

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STERIC EFFECT ON THE FORMATION OF 3H-AZEPINE DERIVATIVES FROM o-ALKYLPHENYLNITRENE AND ALCOHOL AS A NUCLEOPHILIC MEDIA

Siti Mariyah Ulfa, Hideki Okamoto, Kyosuke Satake

HETEROCYCLES   83 ( 6 )   1259 - 1265   2011年6月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

The cause of regioselectivity for the formation of 3-alkyl- and/or 7-alkyl-3H-azepine derivatives via the intramolecular insertion reaction of o-alkylphenylnitrene, which is generated by an action of Buy on o-alkylnitrobenzene, in the presence of alcohol found to be elucidated by the steric effects of an alcohol adduct on the dehydroazepine intermediate. Observed selectivity is confirmed both by changing the bulkiness of the o-alkyl group of phenylnitrene and that of alcohol as a nucleophile.

DOI： 10.3987/COM-11-12172

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Metal-intercalated aromatic hydrocarbons: a new class of carbon-based superconductors 査読

Yoshihiro Kubozono, Hiroki Mitamura, Xuesong Lee, Xuexia He, Yusuke Yamanari, Yosuke Takahashi, Yuta Suzuki, Yumiko Kaji, Ritsuko Eguchi, Koki Akaike, Takashi Kambe, Hideki Okamoto, Akihiko Fujiwara, Takashi Kato, Taichi Kosugi, Hideo Aoki

PHYSICAL CHEMISTRY CHEMICAL PHYSICS   13 ( 37 )   16476 - 16493   2011年

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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 carbon-based superconductors are synthesized by intercalating metal atoms into the solid-phase hydrocarbons picene and coronene. The highest reported superconducting transition temperature, T-c, of a hydrocarbon superconductor is 18 K for K(3)picene. The physics and chemistry of the hydrocarbon superconductors are extensively described for Axpicene (A: alkali and alkali earth-metal atoms) for x = 0-5. The theoretical picture of their electronic structure is also reviewed. Future prospects for hydrocarbon superconductors are discussed from the viewpoint of combining electronics with condensed-matter physics: modification of the physical properties of hydrocarbon solids is explored by building them into a field-effect transistor. The features of other carbon-based superconductors are compared to clarify the nature of hydrocarbon superconductors.

DOI： 10.1039/c1cp20961b

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Phthalide-derived novel fluoroionophores incorporating picolylamino receptors: synthesis and response to metal cations 査読

Hideki Okamoto, Ayako Matsui, Kyosuke Satake

ANALYST   136 ( 15 )   3164 - 3169   2011年

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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  

Phthalide derivatives incorporating mono- and di-picolylamino functionalities at the 6-position have been prepared as novel fluoroionophores and their fluorescence responses to metal cations have been investigated. These phthalides not only exhibited efficient fluorescence in an aqueous medium but also displayed fluorescence on-off response upon addition of transition-metal cations, namely Cu(2+). The 6-aminophthalide fluorophore served as the core of the fluorescent probes although it has rarely been applied to a chemosensor. To the best of our knowledge, these modified phthalides are the first 6-aminophthalide-derived fluorometric probes for metal cations, namely Cu(2+).

DOI： 10.1039/c1an15239d

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Quantitative analysis of O-2 gas sensing characteristics of picene thin film field-effect transistors 査読

Xuesong Lee, Yasuyuki Sugawara, Akio Ito, Shuhei Oikawa, Naoko Kawasaki, Yumiko Kaji, Ryoji Mitsuhashi, Hideki Okamoto, Akihiko Fujiwara, Kenji Omote, Takashi Kambe, Naoshi Ikeda, Yoshihiro Kubozono

ORGANIC ELECTRONICS   11 ( 8 )   1394 - 1398   2010年8月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

O-2 gas sensing behaviors are studied in picene thin film field-effect transistors (FETs) with hydrophobic polymer (Cytop(TM) or polystyrene) coated SiO2 gate dielectrics. Picene thin film FETs show a rapid reduction of hysteresis in transfer curves recorded in forward and reverse measurement modes, compared to a picene FET with hexamethydisilazane-coated SiO2. The picene FETs show very sensitive O-2 gas sensing effects down to similar to 10 ppm. A quantitative analysis is presented of the gate voltage (V-G) dependent mobility induced by O-2 exposure, i.e., the suppression of drain current at high V-G. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.orgel.2010.06.003

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Flexible picene thin film field-effect transistors with parylene gate dielectric and their physical properties 査読

Naoko Kawasaki, Wolfgang L. Kalb, Thomas Mathis, Yumiko Kaji, Ryoji Mitsuhashi, Hideki Okamoto, Yasuyuki Sugawara, Akihiko Fujiwara, Yoshihiro Kubozono, Bertram Batlogg

APPLIED PHYSICS LETTERS   96 ( 11 )   113305   2010年3月

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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 INST PHYSICS  

Flexible picene thin film field-effect transistors (FETs) have been fabricated with parylene gate dielectric on polyethylene terephthalate substrates. The picene thin film FETs show p-channel output/transfer characteristics and the field-effect mobility mu reaches similar to 1 cm(2) V(-1) s(-1) in vacuum. The FET shows a clear O(2) gas sensing effect and negligible hysteresis in the transfer curves, indicating a possible application of the transistor as O(2) selective gas sensor. Furthermore, it has been found that the parylene gate dielectric can eliminate a reduction in on-state drain current caused by continuous bias-voltage application which is observed if a SiO(2) gate dielectric is used.

DOI： 10.1063/1.3360223

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Linear response of multiphoton reaction: Three-photon Cycloreversion of anthracene biplanemer in solution by intense femtosecond laser pulses 査読

Yatsuhashi, T., Nakahagi, Y., Okamoto, H., Nakashima, N.

Journal of Physical Chemistry A   114 ( 39 )   10475 - 10480   2010年

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掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/jp1041475

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Low voltage operation in picene thin film field-effect transistor and its physical characteristics 査読

Yumiko Kaji, Naoko Kawasaki, Xuesong Lee, Hideki Okamoto, Yasuyuki Sugawara, Shohei Oikawa, Akio Ito, Hiroyuki Okazaki, Takayoshi Yokoya, Akihiko Fujiwara, Yoshihiro Kubozono

APPLIED PHYSICS LETTERS   95 ( 18 )   183302/1-183302/3   2009年11月

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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 INST PHYSICS  

Low voltage operation of picene thin film field-effect transistor (FET) has been realized with 40 nm thick SiO(2) gate dielectrics coated by two polymers, Cytop (TM) and polystyrene. The picene FETs operated in low absolute gate voltage vertical bar V(G)vertical bar below 15 V for Cytop (TM) coated SiO(2) and 30 V for polystyrene coated SiO(2) gate dielectrics, and they showed a significant O(2) gas sensing effect down to similar to 10 ppm. Photoemission spectrum clarified that O(2) molecules penetrate into the thin films at O(2)/picene mole ratio of 1: 1. X-ray diffraction pattern of picene thin films showed highly oriented growth on the polymer-coated SiO(2).

DOI： 10.1063/1.3257373

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High-performance C-60 and picene thin film field-effect transistors with conducting polymer electrodes in bottom contact structure 査読

Yumiko Kaji, Ryoji Mitsuhashi, Xuesong Lee, Hideki Okamoto, Takashi Kambe, Naoshi Ikeda, Akihiko Fujiwara, Minoru Yamaji, Kenji Omote, Yoshihiro Kubozono

ORGANIC ELECTRONICS   10 ( 3 )   432 - 436   2009年5月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

C-60 and picene thin film field-effect transistors (FETs) in bottom contact structure have been fabricated with poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PED-OT:PSS) electrodes for a realization of mechanical flexible organic FETs. The C-60 thin film FETs showed n-channel enhancement-type characteristics with the field-effect mobility mu value of 0.41 cm(2\) V-1 s(-1), while the picene thin film FET showed p-channel enhancement-type characteristics with the p of 0.61 cm(2) V-1 s(-1). The p values recorded for C-60 and picene thin film FETs are comparable to those for C-60 and picene thin film FETs with Au electrodes. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.orgel.2009.01.006

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Trap states and transport characteristics in picene thin film field-effect transistor 査読

Naoko Kawasaki, Yoshihiro Kubozono, Hideki Okamoto, Akihiko Fujiwara, Minoru Yamaji

APPLIED PHYSICS LETTERS   94 ( 4 )   043310/1-043310/3   2009年1月

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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 INST PHYSICS  

Transport characteristics and trap states are investigated in picene thin film field-effect transistor under O(2) atmosphere on the basis of multiple shallow trap and release (MTR) model. The channel transport is dominated by MTR below 300 K. It has been clarified on the basis of MTR model that the O(2)-exposure induces a drastic reduction in shallow trap density to increase both the field-effect mobility mu and on-off ratio. We also found that the O(2)-exposure never caused an increase in hole carrier density. Actually, a very high mu value of 3.2 cm(2) V(-1) s(-1) is realized under 500 Torr of O(2).

DOI： 10.1063/1.3076124

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Photochemistry of nitrogen-bridged cyclophanes: 2,11-diaza[32]anthracenoparacyclophane and 2,11-diaza[32]paracyclophane systems 招待 査読

Hideki Okamoto, Minoru Yamaji, Kyosuke Satake

Synlett   ( 13 )   1931 - 1945   2008年8月

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担当区分：筆頭著者,　責任著者   記述言語：英語  

DOI： 10.1055/S-2008-1078574

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A convenient synthesis of trifluoroacetamide derivatives of diaza[3(2)]cyclophanes and triaza[3(3)]cyclophanes 査読

Hideki Okamoto, Hiroyuki Takemura, Kyosuke Satake

SYNTHESIS-STUTTGART   44 ( 1 )   39 - 44   2008年1月

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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）   出版者・発行元：GEORG THIEME VERLAG KG  

The diaza[3(2)]cyclophane skeleton has been constructed by the bis-N-alkylation of 1,4-bis[(4-nitrophenylsulfonylamin o)methyl] benzene with 1,4-bis(halomethyl)benzene in the presence of sodium hydride. The 4-nitrophenylsulfonyl (Ns) amides in the bridge chains of the cyclophane were effectively deprotected by sodium ethanethiolate and the resulting free amine moieties were reprotected as the trifluoroacetamide under mild conditions to afford 3,7-bis(trifluoroacetyl)-3,7-diaza-1,5(1,4)-dibenzenacyclooctaphane in 26% overall yield. This Ns-amide method has also been applied for the preparation of a higher homologue, the trifluoroacetamide derivative of triaza[3(3)]cyclophane, 3,5,7-tris(trifluoroacetyl)-3,7, 10-triaza- 1,5(1,3,5)-dibenzenabicyclo[3.3.3]undecaphane, in 18% overall yield. Thus, the present procedure provides a convenient synthetic route to azacyclophane derivatives possessing trifluoroacetamide groups in the bridge chains.

DOI： 10.1055/s-2007-1000825

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Fluorescence properties of 3-and 4-trifluoroacetylamino-1,8-naphthalimides: Solvent-controlled switching of fluorescence color and response to metal-cations 査読

Hideki Okamoto, Kyosuke Satake, Masaru Kimura

ARKIVOC   8   112 - 123   2007年

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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）   出版者・発行元：ARKAT USA INC  

The effects of solvents and metal cations on the fluorescence spectra of 3- ( 1) and 4- ( 2) trifluoroacetylamino-1,8-naphthalimides were investigated. In MeCN, these naphthalimides displayed a violet similar to blue fluorescence based on their neutral amide form ( 1, 2). Whereas in DMSO, they gave off a yellow similar to orange emission due to their amide anions (1(-), 2(-)). In MeOH, naphthalimide 2 emitted a dual fluorescence (lambda(FL) 436 and 556 nm) to display a white luminescence. Naphthalimides 1, 2 are essentially insensitive to metal cations in their neutral amide form. In contrast, the fluorescence of the amide anions 1-, 2- was quenched by metal cations. The efficiency of the quenching correlated with the Lewis acidity of the metal cations; a stronger Lewis acid tended to display a more effective fluorescence quenching. Therefore, the fluorescence color and the sensitivity to metal cations of the naphthalimides were effectively switched by the solvent.

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Novel parallel reaction between a [1,5] sigmatropic alkylthio shift and a [1,5] sigmatropic hydrogen shift observed in a 2H-azepine ring 査読

Yasuhiro Kubota, Kyosuke Satake, Hideki Okamoto, Masaru Kimura

ORGANIC LETTERS   8 ( 24 )   5469 - 5472   2006年11月

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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  

Although heating 2-methoxy-2H-azepine results in a [1,5] sigmatropic hydrogen shift, heating 2-propylthio-2H-azepine results in not only a [1,5] sigmatropic hydrogen shift but also a [1,5] sigmatropic propylthio shift. Kinetic measurements reveal that migratory aptitudes increase in the order of MeO &lt; H, PrS. These [1,5] sigmatropic shifts are discussed on the basis of ab initio DFT calculations.

DOI： 10.1021/ol062131w

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Invariom structure refinement, electrostatic potential and toxicity of 4-O-methylalpinumisoflavone, O,O-dimethylalpinumisoflavone and 5-O-methyl-4-O-(3-methylbut-2-en-1-yl)alpinum-isoflavone 査読

Robert Kingsford-Adaboh, Birger Dittrich, Christian B. Huebschle, Winfred S. K. Gbewonyo, Hideki Okamoto, Masaro Kimura, Hiroyuki Ishida

ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE   62   843 - 849   2006年10月

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

The accurate X-ray single-crystal structures of the isoflavone compounds 4-O-methylalpinumisoflavone, O, O-dimethylalpinumisoflavone and 5-O-methyl-4-O-( 3-methylbut-2-en-1-yl) alpinumisoflavone {alpinumisoflavone = 5-hydroxy7-( 4-hydroxyphenyl)-2,2-dimethyl-2H, 6H-benzo[ 1,2-b: 5,4-b']dipyran-6-one} from data sets measured at cryogenic temperature have been obtained from invariom modelling using theoretically predicted Hansen and Coppens multipole-model form factors, which describe the aspherical electron density distribution. Molecular dipole moments and electrostatic potentials obtained from invariom modelling are discussed and compared with results from ab initio theoretical calculations. All three studied compounds are solvent extracts of root bark or seed powder of Millettia thonningii ( leguminosae), a plant molluscicide and cercaricide used in Franco West Africa as medication against various diseases. The compounds' toxicities to brine shrimp have been determined and their different potencies tentatively related to conformation differences, intramolecular contacts, dipole moments and electrostatic potential features.

DOI： 10.1107/S0108768106019616

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Formation of 4H-azepine by the electrophilic reaction of a 2-methoxyazepinium ion and analysis of the sigmatropic isomerization 査読

Christopher E. J. Cordonier, Kyosuke Satake, Hideki Okamoto, Masaru Kimura

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY   ( 17 )   3803 - 3807   2006年8月

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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  

2-Aryl-2H-, 3-aryl-3H-, and 4-aryl-4H-azepine were formed by the novel, electrophilic, pi(LUMO)-controlled reaction of the 2-methoxyazepinium ion, generated in situ by the reaction of TiCl4 with 2,7-dialkoxy-2H-azepine and an aryl compound, for which the kinetic parameters of the sigmatropic hydrogen rearrangement of the 4H-azepine was measured. The substitution and hydrogen shift of the azepinium ion were analyzed with DFT studies. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006).

DOI： 10.1002/ejoc.200600257

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Crystal structure of 4ﾕ-O-methylalpinumisoflavone at 90K 査読

Robert Kingsford-Adaboh, E. Ahiano, Birger Dittrich, Hideki Okamoto, Masaru Kimura, Hiroyuki Ishida

Cryst. Res. Technol   41 ( 7 )   728 - 733   2006年7月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/crat.200510656

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An azacrowned phthalimide as a metal-ion sensitive and solvatofluorochromic fluorophore: Fluorescence properties and a mimic integrated logic operation 査読

H Okamoto, M Kohno, K Satake, M Kimura

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   78 ( 12 )   2180 - 2187   2005年12月

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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）   出版者・発行元：CHEMICAL SOC JAPAN  

The novel azacrowned phthalimide 1 has been prepared and its fluorescence properties have been investigated by addition of EtOH and Ag+. The phthalimide 1 showed appreciable solvatofluorochromism; its fluorescence maxima (lambda(FL)) appeared in the wavelength region between 458 (in Et2O) and 544 nm (in EtOH). In benzene, the phthalimide 1 gave off blue emission (lambda(FL) 466 nm) while it emitted green fluorescence (lambda(FL) 497 nm) upon addition of 250 mM of EtOH. Both the blue and the green emissions were quenched by Ag+. Potential logic operations of the phthalimide 1 were examined using fluorescence outputs at 450 (Out(1)) and 515 nm (Out(2)) and two input stimuli, EtOH (In,) and Ag+ (In-2). The Out, was on in the absence of these inputs while its intensity was reduced (off) by either or both of the inputs to serve as a NOR operator. The Out(2) was off without the inputs; in contrast, the intensity of Out(2) was enhanced (on) by In-2. The enhanced Out(2) was switched off by In-2. The Obt(2), thus, corresponds to an INHIBIT operation responding to the input signals. The crowned phthalimide 1 mimics a two-input-two-output combinational logic gate with a single fluorophore and a single ion-sensing unit.

DOI： 10.1246/bcsj.78.2180

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Electrophilic behavior of the pi delocalized azepinium ion: Friedel-crafts reactions with benzenes and five-membered aromatic heterocycles 招待

Y Kubota, K Satake, H Okamoto, M Kimura

ORGANIC LETTERS   7 ( 23 )   5215 - 5218   2005年11月

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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  

Although the reactivity of tropylium ion with aromatic substrates is low, the reaction of azepinium ion with aromatic substrates such as benzene, phenol, furan, and thiophene resulted in the formation of 2-aryl-2H-azepine as a major product. An exceptional result in the formation of ring-contracted product was observed in the reaction with pyrrole.

DOI： 10.1021/ol052049l

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Preparation of an azacrowned isoluminol and its chemiluminescence initiated by alkali-metal iodides in acetonitrile 査読

H Okamoto, M Kimura

CHEMISTRY LETTERS   34 ( 10 )   1452 - 1453   2005年10月

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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  

The novel azacrowned isoluminol has been prepared as the first luminol analogue possessing an azacrown ionophore. The crowned isoluminol displayed flash chemiluminescence upon addition of alkali-metal iodides in acetonitrile containing alkaline hydrogen peroxide and the chemiluminescence intensity varied depending on the metal cations studied; K+ &gt;&gt; Na+ &gt; Li+.

DOI： 10.1246/cl.2005.1452

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Reaction of 2-methoxy-3H-azepine with NBS: Efficient synthesis of 2-substituted 2H-azepines

CEJ Cordonier, K Satake, M Atarashi, Y Kawamoto, H Okamoto, M Kimura

JOURNAL OF ORGANIC CHEMISTRY   70 ( 9 )   3425 - 3436   2005年4月

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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 reaction of 2-methoxy-3H-azepines, in the presence or absence of a nucleophile, with N-bromosuccinimide (NBS) gave a regioselective 1,4-adduct from which the corresponding 2H-azepine derivatives were formed via base-promoted hydrogen bromide elimination, generally in moderate to quantitative yield. Competitive formation of 4-bromo-2-methoxy-3H-azepine by electrophilic substitutuion or 3H-azepin-2-yl 2H-azepin-2-yl ether by transetherification was minimized at lower reaction temperatures. Quantitative substitution of 2-(2',4',6'-trichlorophenoxy)2H-azepine derivatives, formed in moderate yield from the respective 3H-azepine and NBS in the presence of 2,4,6-trichlorophenol (TCP), by various nucleophiles gave the corresponding 2-substituted 2H-azepine. Among these nucleophiles were alkanethiol and alkylamine that are not tolerated in the reaction of 3H-azepine and NBS.

DOI： 10.1021/jo0500232

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Synthesis of a delocalized azepinium ion and investigation of its electrophilic character 招待

K Satake, Y Kubota, CEJ Cordonier, H Okamoto, M Kimura

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   43 ( 6 )   736 - 738   2004年

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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  

DOI： 10.1002/anie.200352794

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Nucleophilic reactions of 5-tert-butyl-2-methoxy-3H-azepine with alkoxides and alkyllithium reagents 査読

Y Kubota, K Satake, R Ikui, H Okamoto, N Kimura

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   76 ( 4 )   805 - 811   2003年4月

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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  

The reaction of 5-tert-butyl-2-methoxy-3H-azepine (2a) with sodium alkoxides gave 2-alkoxy-3H-azepine derivatives 3-6 by nucleophilic transetherification. The treatment of 2a with tert-butyllithium also yielded 2,5-di-tert-butyl-3H-azepine (7): however, the reaction of 2a and methyllithium gave the expected 5-tert-butyl-2-methyl-3H-azepine (8) along with unexpected 5-tert-butyl-2,2-dimethyl-2,3-dihydro-1H-azepine (9). but also 5,5'-di(tert-butyl)-2,2'-methylenedi(3H-azepine) (11), the structure of which was found to be tautomerized 5-tert-butyl-2-(5-tert-butyl-2,3-dihydro-1H-azepine-2-ylidenemethyl)-3H-azepine (12). The energy profile for the observed tautomerization is discussed based on ab initio DFT calculations and kinetic measurements.

DOI： 10.1246/bcsj.76.805

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Photochemistry of N-isopropoxy-substituted 2(1H)-pyridone and 4-p-tolylthiazole-2(3H)-thione: Alkoxyl-radical release (spin-trapping, EPR, and transient spectroscopy) and its significance in the photooxidative induction of DNA strand breaks 査読

W Adam, J Hartung, H Okamoto, S Marquardt, WM Nau, U Pischel, CR Saha-Moller, K Spehar

JOURNAL OF ORGANIC CHEMISTRY   67 ( 17 )   6041 - 6049   2002年8月

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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  

UVA-irradiation of the photo-Fenton reagents N-isopropoxypyridone 2b and N-isopropoxythiazole-2(3H)-thione 3b releases radicals which induce strand breaks. Transient spectroscopy establishes N-O bond scission [Phi(N-O) = (75 8)% for 2b and (65 7)% 3b] as the dominating primary photochemical process to afford the DNA-damaging radicals. Product studies and laser-flash experiments reveal that the thiazolethione 3b leads primarily to the disulfide 5, from which through C-S bond breakage, the bithiazyl 6, the thiazole 7, and the isothiocyanate 8 are derived. Upon irradiation of pyridone 2b (300 nm) in aqueous media, a mixture of isopropoxyl and 2-hydroxyprop-2-yl radicals is formed, as confirmed by trapping with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and EPR spectroscopy. In contrast, the photolysis of the thiazolethione 3b (350 nm) affords exclusively the DMPO adducts of the isopropoxyl radicals. Control experiments disclose that the thiazolethione-derived photoproduct disulfide 5, or the intermediary thiyl radicals B, scavenge the carbon-centered 2-hydroxyprop-2-yl radicals, which are generated from the isopropoxyl radicals by hydrogen shift. With supercoiled pBR 322 DNA in a 60:40 mixture of H2O-MeCN, the pyridone 2b and the thiazolethione 3b display moderate strand-break activity (17% open-circular DNA for 2b and 12% for 3b). In pure water, however, the pyridone 2b photoinduces substantially more DNA cleavage (32% open-circular DNA), which is attributed to the peroxyl radicals generated from the 2-hydroxyprop-2-yl radicals by oxygen trapping. The lower strand-break activity of the thiazolethione 3b derives presumably from isopropoxyl radicals, because only these are detected in the photolysis of this photo-Fenton reagent.

DOI： 10.1021/jo025856w

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Nucleophilic substitution reaction of 5-t-butyl-2methoxy-3H-azepine with alkoxides and alkyllithium reagents: A formation of bis(5-t-butyl-3H-azepin-2-yl)methane having a vinamidine conjugation 査読

K Satake, Y Kubota, H Okamoto, M Kimura

HETEROCYCLES   57 ( 2 )   223 - 228   2002年2月

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Reaction of 5-t-butyl-2-methoxy-3H-azepine (2) with nuclephiles (alkoxides or t-butyllithium) gave respective substitution product at 2-position of the ring. Unexpectedly, when methyllithium was used as a nucleophile, bis(5-t-butyl-3H-azepin-2-yl)methane (7), the structure of which found to be tautomeric vinamidine (7a,b), was formed. Tautomerization between 7 and 7a,b was characterized spectroscopically and theoretically based on the levels of B3LYP/631G(d).

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Photochromic properties of a 2,11-diaza[3,3]paracyclo(9,10)anthracenophane derivative having ethylenediamine host function on its bridge chains 査読

Hideki Okamoto, Yukari Nakatsu, Masaru Kimura, Kyosuke Satake

ITE Lett. Batter. New Technol. Med.   2002年

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担当区分：筆頭著者  

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Preparation of a crown-ether-modified lophine peroxide as a guest-sensitive novel chemiluminophore and modulation of its chemiluminescence by metal cations 査読

H Okamoto, M Owari, M Kimura, K Satake

TETRAHEDRON LETTERS   42 ( 42 )   7453 - 7455   2001年10月

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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）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

A guest-sensitive chemiluminophore, a novel crown-ether-modified lophine peroxide 1. has been prepared. and its chemiluminescent behavior has been investigated in the presence of alkaline and alkaline earth metal cations. In the presence of Na+, the lambda (max) of the chemiluminescence of peroxide 1 was blue-shifted (505 nm) compared to the case without a metal cation (566 nm). The chemiluminescent intensity was enhanced by addition of Na+ while that of Mg2+ decreased the intensity. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(01)01572-6

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N-Hydroxy-4-(4-chlorophenyl)thiazole-2(3H)-thione as a photochemical hydroxyl-radical source: photochemistry and oxidative damage of DNA (strand breaks) and 2’-deoxyguanosine (8-oxodG formation) 査読

Waldemar Adam, Jens Hartung, Hideki Okamoto, Chantu Saha-M&ouml, ller, Kristina Spehar

Photochem. Photobiol.   72 ( 5 )   619 - 624   2000年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1562/0031-8655(2000)072<0619:NHCTHT>2.0.CO;2

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Sensitized irradiation of anthracene-benzene biplanemers: Formation of adducts of a benzvalene or a Dewar benzene with anthracene 査読

Masaru Kimura, Hideki Okamoto, Zhi Zhi Hu, Setsuo Kashino

ITE Lett. Batter. New Technol. Med.   2000年

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Circular polarization of photochemiluminescence from the photoisomer of a conformationally fixed 2,11-diaza[3.3](9,10)anthracenoparacyclophane derivative 査読

Hideki Okamoto, Harry P. J. M. Dekkers, Kyosuke Satake, Masaru Kimura

Chemical Communications   ( 9 )   1049 - 1050   1998年5月

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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）   出版者・発行元：Royal Society of Chemistry  

The conformation of 2,11-diaza[3.3](9,10)anthracenoparacyclophane 1, which underwent photointerconversion with isomer 2, was fixed with the aid of a chiral camphanic auxiliary to have molecular chirality, and the photochemiluminescence from the modified 2a was circularly polarized reflecting the chirality of the emitting state.

DOI： 10.1039/a801296b

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Synthesis and characterization of 2-methoxy-2H-azepines: The first isolation of 2-azanorcaradiene, the valence isomer of 3H-azepine

Kyosuke Satake, Yuko Tawada, Hideki Okamoto, Masaru Kimura

Journal of the Chemical Society - Perkin Transactions 1   ( 14 )   2015 - 2017   1997年7月

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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 Society of Chemistry  

The selective formation of 2-methoxy-2H-azepine from 3H-azepines, via a likely azatropylium cation, is reported
the first isolation of 2-azanorcaradiene, which is considered to be the valence isomer of 3H-azepine, is also described.

DOI： 10.1039/a703709k

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Adiabatic photocycloreversion of bridged benzene-anthracene biplanemers: Controlling of the efficiency of the excited product formation by auxiliary substituents on the side-chains 査読

Hideki Okamoto, Kyosuke Satake, Masaru Kimura

Chemistry Letters   ( 9 )   873 - 874   1997年

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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）   出版者・発行元：Chemical Society of Japan  

The efficiency for excited product formation in the adiabatic photocycloreversion of bridged biplanemer 1 was controlled by the size of its side-chain substituents which changed the interchromophore distance in the photoproduct 2.

DOI： 10.1246/cl.1997.873

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Rearrangement of bicyclo[2.2.2]octa-2,5-diene and bicyclo[3.2.2]nona-6,8-diene under the conditions of bromination 査読

Kyosuke Satake, Kazuyuki Hikasa, Hajime Itoh, Hideki Okamoto, Masaru Kimura, Shiro Morosawa

Bulletin of the Chemical Society of Japan   69 ( 2 )   453 - 457   1996年

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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 Society of Japan  

A reaction of electrophilic bromination of norbornadiene homologs such as bicyclo[2.2.2]octa-2,5-diene (4) and bicyclo[3.2.2]nona-6,8-diene (7) with bromine gave hitherto unknown skeleton rearranged dibromides. The rearrangement may proceed via a bromonium cation of starting diene to give bicyclo[3.2.1]octene or bicyclo[3.3.1]nonene skeleton in respective cases. The observed rearrangement reactions are also confirmed in 6,7-bis(methoxycarbonyl) derivatives of bicyclodiene 7 under similar conditions.

DOI： 10.1246/bcsj.69.453

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A new ring contraction rearrangement of 2,5-and 3,6-di-tert-butyl-3H-azepines to pyridine derivatives 査読

Kyosuke Satake, Koichi Takaoka, Michiaki Hashimoto, Hideki Okamoto, Masaru Kimura, Shiro Morosawa

Chemistry Letters   ( 12 )   1129 - 1130   1996年

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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 Society of Japan  

A new ring contraction reaction giving pyridine derivatives from 3,6-and 2,5-di-tert-butyl-3H-azepines was observed by a successive treatment with bromine and aqueous K2CD3. A plausible mechanism via azatropilium cation for the rearrangement was discussed based on the product's distribution from respective 3H-azepines.

DOI： 10.1246/cl.1996.1129

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Characterization of a Longicyclic (2,2,2,2) Conjugated π System in 1,4-Difluorobenzene-Naphthalene Biplanemer

OKAMOTO Hideki, SATAKE Kyosuke, KIMURA Masaru

Bulletin of the Chemical Society of Japan   68 ( 12 )   3557 - 3562   1995年12月

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記述言語：英語   出版者・発行元：The Chemical Society of Japan  

The electronic absorption spectrum of a 1,4-difluorobenzene–naphthalene biplanemer 1 exhibited a characteristic absorption band around 290 nm. This was attributable to intramolecular charge transfer interaction between the longicyclic conjugated π system and the benzene chromophore. The oxidation potential of 1 was 1.70 V (vs. Ag/AgCl), which was lower than those of the related compounds in which one of the double bonds of 1 was hydrogenated. Thermally, the biplanemer 1 underwent facile Cope rearrangement, followed by dehydrofluorination, to give 1-(4-fluorophenyl)naphthalene and 2-(3-fluorophenyl)naphthalene.

DOI： 10.1246/bcsj.68.3557

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Demethoxycarbonylation of methyl 2,5- and methyl 3,6-dialkyl-1H-azepine-1 carboxylates: Formation and characterization of 2H-, 3H- and 4H-azepines

Kyosuke Satake, Ryoichi Okuda, Michiaki Hashimoto, Yasusi Fujiwara, Hideki Okamoto, Masaru Kimura, Shiro Morosawa

Journal of the Chemical Society, Perkin Transactions 1   ( 13 )   1753 - 1757   1994年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Demethoxycarbonylation of methyl 2,5-di-tert-butyl-1H-azepine-1-carboxylate using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) gave 3H-azepines. Under similar conditions, methyl 3,6-ditert-butyl-1H-azepine-1-carboxylate gave not only the 3H-azepine but also the isomerized 2H- and 4H-azepines. Application of the reaction to dimethyl and diisopropyl substituted 1H-azepines showed that bulky alkyl group substitution stabilizes the seven-membered azatriene system. The thermal behaviour of the di-tert-butyl substituted azepines is discussed.

DOI： 10.1039/p19940001753

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Synthesis and Adiabatic Photochemistry of a 1,4-Difluorobenzene-Naphthalene Biplanemer. 査読

Okamoto Hideki, Kimura Masaru, Satake Kyosuke, Morosawa Shiro

Bulletin of the Chemical Society of Japan   66 ( 8 )   2436 - 2439   1993年

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担当区分：筆頭著者   記述言語：英語   出版者・発行元：The Chemical Society of Japan  

A naphtalene-1,4-difluorobenzene biplanemer 1a has been prepared through the electrolytic oxidative didecarboxylation. The direct irradiation of 1a gave 1,4-difluorobenzene and excited naphthalene in both a singlet state (Φ_f = 0.098) and a triplet state (Φ_p = 0.029) at 77 K in EPA. In the triplet-sensitized reaction, the biplanemer 1a underwent intramolecular [2π+2π] cycloaddition to give a cage compound instead of the formation of the triplet naphthalene.

DOI： 10.1246/bcsj.66.2436

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Detection and thermal properties of 1,4-Difluorobenzene-naphthoquinone Biplanemer: A new longicyclic π system 査読

Masaru Kimura, Koji Sirasu, Hideki Okamoto, Kyosuke Satake, Shiro Morosawa

Tetrahedron Letters   33 ( 46 )   6975 - 6978   1992年11月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

9,10-difluorotetracyclo[6.4.21,8.29,12.02,7]hexadeca-2,4,6,10,13,15-hexaene-3, 6-dione is thermally labile and shows a notably clear, long wave-length CT absorption. © 1992.

DOI： 10.1016/S0040-4039(00)60910-3

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The Base-Catalyzed H/D-Exchange of Anisole Moiety of Ruthenium Complex in Cooperation with Demethylation by Hydroxide Anion in Methanol-d₄

Kimura Masaru, Morita Mitsunobu, Mitani Hideo, Okamoto Hideki, Satake Kyosuke, Morosawa Shiro

Bulletin of the Chemical Society of Japan   65 ( 9 )   2557 - 2559   1992年

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記述言語：英語   出版者・発行元：公益社団法人 日本化学会  

[Ru(&eta;⁵-C₅H₅)(&eta;⁶-arene A)]BF₄ (arene A = nitrobenzene, m- or p-nitrotoluene, anisole, phenetole, m- or p-methylanisole) were quantitatively converted to pure [Ru(&eta;⁵-C₅H₅)(&eta;⁶-arene B)]BF₄ (arene B = phenoxido-2d m- or p-monodeuterated methylphenoxido) in the presence of excess KOH in CD₃OD, whereas [Ru(&eta;⁵-C₅H₅)(&eta;⁶-anisole)] BF₄ was quantitatively obtained by treatment [Ru(&eta;⁵-C₅H₅)(&eta;⁶-nitrobenzene)] BF₄ with 1 equivalent KOH or CH₃OK.

DOI： 10.1246/bcsj.65.2557

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Synthesis and characterization of 2H-, 3H- and 4H-azepine: The first observation of the thermal distribution equilibrium of azepines 査読

Kyosuke Satake, Ryoichi Okuda, Michiaki Hashimoto, Yasushi Fujiwara, Izumi Watadani, Hideki Okamoto, Masaru Kimura, Shiro Morosawa

Journal of the Chemical Society, Chemical Communications   ( 17 )   1154 - 1156   1991年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Demethoxycarbonylation of methyl 2,5,-di-tert-butyl-1H-azepine-1- carboxylate using 1,8-diazabicyclo[5.4.0]undec-7-ene gives exclusively two isomers of 3H-azepine derivatives, while methyl 3,6-di-tert-butyl-1H-azepine-1- carboxylate gives a mixture of 2H-, 3H- and 4H-azepine derivatives under the same conditions because of a 1,5-hydrogen shift in the resulting triene system.

DOI： 10.1039/C39910001154

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A Desirable Route to Heterodimers of 1,4-Dihalobenzenes and Anthracene and Their Photoproperties and Thermal Properties 査読

Masaru Kimura, Hideki Okamoto, Hisatoshi Kura, Ayumi Okazaki, Eiji Nagayasu, Kyosuke Satake, Shiro Morosawa, Masayoshi Fukazawa, Hamzer Abdel-Halim, D. O. Cowan

Journal of Organic Chemistry   53 ( 17 )   3908 - 3911   1988年8月

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Electronic oxidative bisdecarboxylation of photoadducts of 2,5-dihalo-1,2-dihydrophthalic anhydride and anthracene gave the corresponding energy-rich heterodimers 12 and 13. The quantum yields of the formation of the excited anthracene from 12 and 13 by the irradiation of 280-nm light were 0.65 and 0.25, respectively. We assumed that the heterodimers of 12 and 13 form biradicaloid intermediates during thermal retro [4πs + 4πs] cycloaddition and consumed their stored energy without any visible light. However, we observed emission light from 340 to 460 nm through a glass filter and the formation of anthracene using Nd-YAG laser IR light (1.06 μm) by the multiphoton absorption, when fine powders of 12 and 13 were used. © 1988, American Chemical Society. All rights reserved.

DOI： 10.1021/jo00252a004

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Synthesis and photochemistry of 3, 6-difluoro-10,11-benzopentacyclo-[6,4,0.0&lt;sup&gt;2.7&lt;/sup&gt;,0&lt;sup&gt;3.12&lt;/sup&gt;.0&lt;sup&gt;6.9&lt;/sup&gt;]dodeca-4,10-diene 査読

Masaru Kimura, Hisatoshi Kura, Kastumi Nukada, Hideki Okamoto, Kyosuke Satake, Shiro Morosawa

Journal of the Chemical Society, Perkin Transactions 1   ( 12 )   3307 - 3310   1988年

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

9,12-Difluoro-and 9,12-dichlorotetracyclo[6.4.2.2&lt
sup&gt
9.12&lt
/sup&gt
.0&lt
sup&gt
2.7&lt
/sup&gt
] hexadeca-2,4,6,13,15-pentaene-10,11 -dicarboxylic anhydrides (2a) and (2b) were prepared by 4π&lt
inf&gt
s&lt
/inf&gt
+ 4π&lt
inf&gt
s&lt
/inf&gt
is photocycloaddition between cis-3,6-difluoro-or cis-3,6-dichloro-1,2-dihydrophthalic anhydride and naphthalene, respectively. 12, 15-Difluoro-and 12, 15-dichlorohexacyclo [8.6.0.0&lt
sup&gt
2.15&lt
/sup&gt
.0&lt
sup&gt
3.8&lt
/sup&gt
.0&lt
sup&gt
9.12&lt
/sup&gt
.0&lt
sup&gt
11.16&lt
/sup&gt
] hexadeca-3,5,7-triene-13,14-dicar-boxylic anhydrides (6a) and (6b) were obtained by 2π&lt
inf&gt
s&lt
/inf&gt
+ 2π&lt
inf&gt
s&lt
/inf&gt
is intramolecular photocycloaddition of adducts (2a) and (2b), respectively. 12,15-Difluorohexacyclo[8.6.0.0&lt
sup&gt
2.15&lt
/sup&gt
.0&lt
sup&gt
3.8&lt
/sup&gt
.0&lt
sup&gt
9.12&lt
/sup&gt
.0&lt
sup&gt
11.16&lt
/sup&gt
]hexadeca-3,5,7,13-tetraene (7a) has been synthesized by the electro-oxidative decarboxylation of anhydride (6a) and the excited singlet naphthalene has been observed on irradiation of adduct (7a), and is presumably formed via an adiabatic pathway. © 1988, The Royal Society of Chemistry.

DOI： 10.1039/P19880003307

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