Hayato Tsuji

Find an error

Name:

Organization: The University of Tokyo , Japan

Department: Department of Chemistry

Title: Assistant Professor(PhD)

TOPICS

Organic Chemistry

Organometallics Dye Sensitized Solar Cell

Material Chemistry

Dye Sensitized Solar Cell

Chemicals
References

Planarization, Fusion, and Strain of Carbon-Bridged Phenylenevinylene Oligomers Enhance π-Electron and Charge Conjugation: A Dissectional Vibrational Raman Study

Co-reporter:Paula Mayorga Burrezo; Xiaozhang Zhu; Shou-Fei Zhu; Qifan Yan; Juan T. López Navarrete; Hayato Tsuji; Eiichi Nakamura;Juan Casado

Journal of the American Chemical Society 2015 Volume 137(Issue 11) pp:3834-3843

Publication Date(Web):March 2, 2015

DOI:10.1021/ja5125463

We have used Raman spectroscopy to study the molecular and electronic structures of the radical cations and dications of carbon-bridged oligo(para-phenylenevinylene)s (COPVn, n = 1–6) possessing consecutive fused pentagons and hexagons, up to 19, along with COPV derivatives having electron-donating and -withdrawing groups. This study was made possible by the outstanding stability of the charged states of COPVs. We could untangle the effects of π-conjugation in the planar structure on the Raman frequency by distinguishing it from other structural effects, such as strain in the vinylene groups shared by the two pentagons. The analyses showed that the radical cations have benzo-quinoidal structures confined in the center of the molecule, as well as benzo-aromatic rings at the terminal sites. In contrast, dications of COPVn longer than n = 3 exhibit a biradicaloid character because of the recovery of aromaticity in the central rings and quinoidal rings at the terminal positions. These biradicaloids favor a singlet nature in their ground electronic states because of the double spin polarization. The introduction of electron-donating and -withdrawing groups on the termini of a COPV core affords, upon oxidation or reduction, a fully delocalized class III mixed valence system because of the high degree of conjugation of the COPV platform, which favors extensive charge delocalization.

The hydrogen/deuterium isotope effect of the host material on the lifetime of organic light-emitting diodes

Co-reporter:Hayato Tsuji, Chikahiko Mitsui and Eiichi Nakamura

Chemical Communications 2014 vol. 50(Issue 94) pp:14870-14872

Publication Date(Web):15 Sep 2014

DOI:10.1039/C4CC05108D

The hydrogen/deuterium primary kinetic isotope effect provides useful information about the degradation mechanism of OLED host materials. Thus, replacement of labile C–H bonds in the host with C–D bonds increases the device lifetime by a factor of five without loss of efficiency, and replacement with C–C bonds by a factor of 22.5.

Synthesis, Crystal Packing, and Ambipolar Carrier Transport Property of Twisted Dibenzo[g,p]chrysenes

Co-reporter:Dr. Yasuyuki Ueda;Dr. Hayato Tsuji;Dr. Hideyuki Tanaka;Dr. Eiichi Nakamura

Chemistry – An Asian Journal 2014 Volume 9( Issue 6) pp:1623-1628

Publication Date(Web):

DOI:10.1002/asia.201402102

Abstract

A versatile method for the synthesis of dibenzo[g,p]chrysene (DBC) derivatives based on regio- and stereoselective stannyllithiation to diarylacetylenes is described. This method affords a variety of DBCs possessing both electron-donating and electron-withdrawing functional groups. These twisted molecules take brickwork packing structures in single crystals. Thus, ambipolar carrier transport properties with mobility values of up to 10⁻³ cm² V⁻¹ s⁻¹ in the amorphous state were achieved. Functional groups on DBC frameworks are considered to increase carrier mobility through the enhancement of intermolecular interactions in the brickwork packing structures.

New sensitizers for dye-sensitized solar cells featuring a carbon-bridged phenylenevinylene

Co-reporter:Xiaozhang Zhu, Hayato Tsuji, Aswani Yella, Anne-Sophie Chauvin, Michael Grätzel and Eiichi Nakamura

Chemical Communications 2013 vol. 49(Issue 6) pp:582-584

Publication Date(Web):04 Dec 2012

DOI:10.1039/C2CC37124C

We demonstrate that a carbon-bridged phenylenevinylene (CPV)-linked dye serves as a novel and efficient sensitizer for dye-sensitized solar cells. The cells show IPCE values of greater than 90%, PCEs of up to 7.12%, and high open circuit voltages reaching close to 0.8 V based on the iodide/triiodide electrolyte.

Synthesis of Benzotrifuran and Benzotripyrrole Derivatives and Molecular Orientations on the Surface and in the Solid State

Co-reporter:Dr. Hayato Tsuji;Dr. Guillaume Cantagrel;Yasuyuki Ueda;Dr. Ting Chen;Dr. Li-Jun Wan;Dr. Eiichi Nakamura

Chemistry – An Asian Journal 2013 Volume 8( Issue 10) pp:2377-2382

Publication Date(Web):

DOI:10.1002/asia.201300106

Abstract

We developed a concise synthetic method for benzotrifurans and benzotripyrroles from 1,3,5-triethynyl-2,4,6-trifluorobenzenes by one-pot reactions in good to excellent yield. By investigating 2-D and 3-D structures of a variety of benzotrifuran and benzotripyrrole derivatives using scanning tunneling microscopy (STM) and single-crystal X-ray diffraction techniques, we found both similarities and dissimilarities. We also found that diverse molecular 3-D orientations were derived in their single crystals according to substituents on the molecules and that the emission properties in the solid state are dependent on their packing manners.

Naphtho[2,1-b:6,5-b′]difuran: A Versatile Motif Available for Solution-Processed Single-Crystal Organic Field-Effect Transistors with High Hole Mobility

Co-reporter:Chikahiko Mitsui ; Junshi Soeda ; Kazumoto Miwa ; Hayato Tsuji ; Jun Takeya ;Eiichi Nakamura

Journal of the American Chemical Society 2012 Volume 134(Issue 12) pp:5448-5451

Publication Date(Web):March 14, 2012

DOI:10.1021/ja2120635

We here report naphtho[2,1-b:6,5-b′]difuran derivatives as new p-type semiconductors that achieve hole mobilities of up to 3.6 cm2 V–1 s–1 along with high Ion/Ioff ratios in solution-processed single-crystal organic field-effect transistors. These features originate from the dense crystal packing and the resulting large intermolecular π-orbital overlap as well as from the small reorganization energy, all of which originate from the small radius of an oxygen atom.

Carbon-Bridged Oligo(phenylenevinylene)s: Stable π-Systems with High Responsiveness to Doping and Excitation

Co-reporter:Xiaozhang Zhu ; Hayato Tsuji ; Juan T. López Navarrete ; Juan Casado ;Eiichi Nakamura

Journal of the American Chemical Society 2012 Volume 134(Issue 46) pp:19254-19259

Publication Date(Web):October 29, 2012

DOI:10.1021/ja309318s

The high responsiveness of π-conjugated materials to external stimuli, such as electrons and photons, accounts for both their utility in optoelectronic applications and their chemical instability. Extensive studies on heteroatom-stabilized π-conjugated systems notwithstanding, it is still difficult to combine high performance and stability. We report here that carbon-bridged oligo(p-phenylenevinylene)s (COPV-n) are not only more responsive to doping and photoexcitation but also more stable than the conventional p-phenylenevinylenes and poly(3-hexylthiophene), surviving photolysis very well in air, suggesting that they could serve as building blocks for optoelectronic applications. Activation of the ground state by installation of bond angle strain toward the doped or photoexcited state and the flat, rigid, and hindered structure endows COPVs with stimuli-responsiveness and stability without recourse to heteroatoms. For example, COPV-6 can be doped with an extremely small reorganization energy and form a bipolaron delocalized over the entire π-conjugated system. Applications to bulk and molecular optoelectronic devices are foreseen.

Air- and Heat-Stable Planar Tri-p-quinodimethane with Distinct Biradical Characteristics

Co-reporter:Xiaozhang Zhu ; Hayato Tsuji ; Koji Nakabayashi ; Shin-ichi Ohkoshi ;Eiichi Nakamura

Journal of the American Chemical Society 2011 Volume 133(Issue 41) pp:16342-16345

Publication Date(Web):September 20, 2011

DOI:10.1021/ja206060n

A heptacyclic carbocycle possessing three p-quinodimethane units conjugated in one plane has been synthesized and shown to exhibit distinct biradical characteristics. The molecule has a HOMO/LUMO band gap of ca. 1 eV and a S0–T1 energy gap of 2.12 kcal/mol, and it absorbs and emits near-IR light at room temperature. It is air-stable under ambient light for several months and thermally stable up to 160 °C under nitrogen, and it undergoes reversible two-electron oxidation and reduction. The synthetic approach is such that a smaller and larger oligo-p-quinodimethane can be synthesized.

Modular synthesis and photophysical and electrochemical properties of 2,3,5,6-tetraaryl-substituted benzo[1,2-b:5,4-b]difurans

Co-reporter:Hayato Tsuji;Chikahiko Mitsui;Yoshiharu Sato;Eiichi Nakamura

Heteroatom Chemistry 2011 Volume 22( Issue 3-4) pp:316-324

Publication Date(Web):

DOI:10.1002/hc.20682

Abstract

We developed a versatile synthesis of tetraaryl-substituted benzo[1,2-b:5,4-b′]difurans (m-BDFs) via a zinc-mediated intramolecular double cyclization reaction of 4,6-bis(phenylethynyl)-1,3-benzenediol, followed by a palladium-catalyzed cross-coupling reaction. In comparison with the corresponding benzo[1,2-b:4,5-b′]difuran (p-BDF) isomers reported previously, the m-BDFs are slightly wider between HOMO and LUMO, as well as a lower energy level of the former. These differences in properties between the structural isomers can be ascribed to the difference in the conjugation type. The compounds had high charge carrier mobility up to 1 × 10⁻³ cm²/Vs, which makes them attractive materials for organoelectronics applications. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:316–324, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20682

Synthesis of Tetrasubstituted Alkenes by Stereo- and Regioselective Stannyllithiation of Diarylacetylenes

Co-reporter:Hayato Tsuji ; Yasuyuki Ueda ; Laurean Ilies ;Eiichi Nakamura

Journal of the American Chemical Society 2010 Volume 132(Issue 34) pp:11854-11855

Publication Date(Web):August 10, 2010

DOI:10.1021/ja1059119

Addition of trimethylstannyllithium to a diarylacetylene takes place exclusively in an anti-fashion to produce a lithio vinylstannane intermediate. The regioselectivity of the addition is controlled by the steric and electronic property of the acetylene and reaches up to >99:1. The two newly formed C−metal bonds can be sequentially and stereospecifically transformed into two new C−C bonds as illustrated by stereoselective synthesis of 4-hydroxytamoxifen and its regioisomer. A tetraarylethene bearing different aryl groups can be synthesized similarly and cyclized to a substituted dibenzo[g,p]chrysene derivative via a palladium-catalyzed arylation reaction.

Bis(carbazolyl)benzodifuran: A High-Mobility Ambipolar Material for Homojunction Organic Light-Emitting Diode Devices

Co-reporter:Hayato Tsuji;Chikahiko Mitsui;Yoshiharu Sato;Eiichi Nakamura

Advanced Materials 2009 Volume 21( Issue 37) pp:3776-3779

Publication Date(Web):

DOI:10.1002/adma.200900634

Modular Synthesis of 1H-Indenes, Dihydro-s-Indacene, and Diindenoindacene—a Carbon-Bridged p-Phenylenevinylene Congener

Co-reporter:Xiaozhang Zhu ; Chikahiko Mitsui ; Hayato Tsuji ;Eiichi Nakamura

Journal of the American Chemical Society 2009 Volume 131(Issue 38) pp:13596-13597

Publication Date(Web):September 3, 2009

DOI:10.1021/ja905626b

A variety of 1H-indenes, dihydro-s-indacenes, and diindenoindacenes, carbon-bridged phenylenevinylene derivatives, can be synthesized in good to high yields using as a synthetic module a 3-lithioindene compound made available by reductive cyclization of an alkynylbenzene derivative. The planar analogues of oligophenylenevinylene compounds thus synthesized show physical properties beneficial for use as ambipolar organic semiconductor materials.

Benzo[b]phosphole sulfides. Highly electron-transporting and thermally stable molecular materials for organic semiconductor devices

Co-reporter:Hayato Tsuji, Kosuke Sato, Yoshiharu Sato and Eiichi Nakamura

Journal of Materials Chemistry A 2009 vol. 19(Issue 21) pp:3364-3366

Publication Date(Web):29 Apr 2009

DOI:10.1039/B906197E

A benzo[b]phosphole sulfide derivative DBPSB was found to function as a new class of n-type amorphous organic material, which features high electron drift mobility and high thermal stability, and the utility of this compound was demonstrated in an organic light-emitting diode.

Synthesis of Benzo[b]siloles via KH-Promoted Cyclization of (2-Alkynylphenyl)silanes

Co-reporter:Laurean Ilies, Hayato Tsuji and Eiichi Nakamura

Organic Letters 2009 Volume 11(Issue 17) pp:3966-3968

Publication Date(Web):August 7, 2009

DOI:10.1021/ol9015282

(2-Alkynylphenyl)silanes undergo intramolecular cyclization in the presence of an excess or a subequimolar amount of potassium hydride to give a variety of new 2-substituted benzosiloles in good to excellent yields. Some of these compounds showed a high fluorescence quantum yield both in solution and in the solid state, and they also showed reversible reduction in THF.

Synthesis and Electronic Spectra of Disilatriptycene Oligomers: Evidence for Electronic Delocalization along the One-Dimensional Arrangement of Bridge-Head Disilanes

Co-reporter:Shohei Sase, Yoen-Seok Cho, Atsushi Kawachi, Atsushi Wakamiya, Shigehiro Yamaguchi, Hayato Tsuji and Kohei Tamao

Organometallics 2008 Volume 27(Issue 21) pp:5441-5445

Publication Date(Web):September 27, 2008

DOI:10.1021/om701283e

Reductive coupling of a 9,10-dibromo-9,10-disilatriptycene derivative followed by treatment with chlorotrimethylsilane (TMSCl) affords a series of TMS-capped 9,10-disilatriptycene oligomers DSiT[n]. Each isomer, up to the pentamer (n = 5), can be separated using recycling gel permeation chromatography. The X-ray structural analysis of DSiT[2] shows that the six silicon atoms are linearly aligned in a rigid array structure. While the ultraviolet (UV) absorption maximum remains constant at 230 nm, irrespective of the chain length, the magnetic circular dichroism (MCD) spectra exhibit a red shift band near 245 nm, and the emission maximum steadily shifts from 319 to 337 nm as the number of silicon atom increases. These spectra indicate the occurrence of electronic delocalization along the one-dimensional arrangement of bridge-head disilane moieties.

The hydrogen/deuterium isotope effect of the host material on the lifetime of organic light-emitting diodes

Co-reporter:Hayato Tsuji, Chikahiko Mitsui and Eiichi Nakamura

Chemical Communications 2014 - vol. 50(Issue 94) pp:NaN14872-14872

Publication Date(Web):2014/09/15

DOI:10.1039/C4CC05108D

New sensitizers for dye-sensitized solar cells featuring a carbon-bridged phenylenevinylene

Co-reporter:Xiaozhang Zhu, Hayato Tsuji, Aswani Yella, Anne-Sophie Chauvin, Michael Grätzel and Eiichi Nakamura

Chemical Communications 2013 - vol. 49(Issue 6) pp:NaN584-584

Publication Date(Web):2012/12/04

DOI:10.1039/C2CC37124C

Benzo[b]phosphole sulfides. Highly electron-transporting and thermally stable molecular materials for organic semiconductor devices

Co-reporter:Hayato Tsuji, Kosuke Sato, Yoshiharu Sato and Eiichi Nakamura