Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Kenta Goto Last modified date:2021.11.17

Assistant Professor / Department of Chemistry, Graduate School of Sciences / Department of Applied Molecular Chemistry / Institute for Materials Chemistry and Engineering

1. Kenta Goto, Mizue Asada, Toshikazu Nakamura, Fumito Tani, Switching Photomechanical Response by a Structural Phase Transition in a Naphthalene Diimide Derivative, ChemPhotoChem, 10.1002/cptc.201900269, 4, 3, 218-223, 2020.03, A newly prepared photoresponsive material, specifically a naphthalene diimide molecule containing alkylamino groups, was found to exhibit a structural phase transition in the crystalline state. The phase transition dramatically altered the molecular arrangement from orthogonal pi-pi stacking to parallel pi-pi stacking. The photomechanical response of each crystal was also changed before and after the phase transition. While the as-prepared crystal immediately responded to light irradiation (lambda=370 nm), the responsiveness of the crystal became slower after heat treatment. Upon light irradiation, radical species, such as the radical anion, radical anion dimer, and mixed valence species, were formed, which have nearly the same distribution in both phases. However, the spin system and the structure of the radical anion were quite different from each other and were found to be sensitive to the molecular arrangement. The photo-responsiveness of the crystals was corroborated by evaluating the relaxation of the radical anion..
2. Keita Tani, Risa Imafuku, Kanae Miyanaga, Miyuki Eiraku Masaki, Haruka Kato, Kazushige Hori, Koji Kubono, Masatsugu Taneda, Takunori Harada, Kenta Goto, Fumito Tani, Tadashi Mori, Combined Experimental and Theoretical Studies on Planar Chirality of Partially Overlapped C2-Symmetric [3.3](3,9)Dicarbazolophanes, Journal of Physical Chemistry A, 10.1021/acs.jpca.0c00286, 124, 10, 2057-2063, 2020.03, Partially overlapped dicarbazolophanes exhibit a planar chirality. In this study, C2-symmetrical [3.3](3,9)dicarbazolophane derivatives (CZ1-CZ3) have been optically resolved by preparative chiral high-performance liquid chromatography for the first time. In their circular dichroism (CD) spectra, moderate Cotton effects (CEs) were observed for their 1Lb and 1La transitions (|Δϵ| = 10-12 and 51-57 M-1 cm-1, respectively), while intense CEs were notified in their 1B transitions (|Δϵ| = 156-216 M-1 cm-1), absorption dissymmetry (gabs) factors being in orders of 10-2. Circularly polarized luminescence spectrum was also obtained for cyanamide derivative CZ1, with a comparative luminescence dissymmetry (glum) factor of 0.013. A computational investigation was applied to address the factors for such remarkable chiroptical responses in these dicarbazolophanes of planar chirality. Absolute configurations were unambiguously determined by the comparison of experimental and theoretical CD spectra, which was affirmed by the X-ray crystal structural analysis of enantiomerically pure sulfonamide derivative CZ2..
3. Shuhei Ogata, Hiroaki Komiya, Naoto Goto, Ryota Tanabe, Kunihisa Sugimoto, Shogo Kawaguchi, Kenta Goto, Miho Hatanaka, Ayumi Ishii, Miki Hasegawa, Strong luminescent europium complexes induced by the unprecedented anti-chelate effect of acyl groups on a N6-hexadentate ligand, Chemistry Letters, 10.1246/cl.190140, 48, 6, 593-596, 2019.01, An acyl group derived-bipyridine ligand and Eu form 3:2 complexes. The structure and luminescence behaviour were evaluated, and we found an unexpected bi-nuclear complex system, which induces efficiently the luminescence of europium ion. This observation is discussed from experimental and theoretical viewpoints..
4. Masahiro Narita, Takaaki Teraoka, Toshihiro Murafuji, Yoshihito Shiota, Kazunari Yoshizawa, Shigeki Mori, Hidemitsu Uno, Shinji Kanegawa, Osamu Sato, Kenta Goto, Fumito Tani, An azulene-based chiral helicene and its air-stable cation radical, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.20190219, 92, 11, 1867-1873, 2019.01, A helicene compound called AIBTh, wherein two azulene units are fused with isobenzothiophene, has been prepared and characterized by spectroscopic and crystallographic methods. The enantiomers of AIBTh were resolved by HPLC, exhibiting stable optical activity. AIBTh showed two reversible oxidation and one irreversible reduction waves with a HOMO-LUMO gap of 2.07 eV. Upon one-electron oxidation of AIBTh, its air-stable cation radical was isolated and analyzed by EPR as well as X-ray crystallography. Based on the EPR spectrum, the crystal structure, and DFT calculation, it is suggested that favorable resonance structures including aromatic tropylium cation forms and wide delocalization of electronic spin are dominating in the electronic structure of the cation radical..
5. Minoru Yamaji, Kazuhiro Tomonari, Keisuke Ikuma, Kenta Goto, Fumito Tani, Hideki Okamoto, Blue fluorescence from
N, O -coordinated BF2 complexes having aromatic chromophores in solution and the solid state, Photochemical and Photobiological Sciences, 10.1039/c9pp00410f, 18, 12, 2884-2892, 2019.01, We prepared amide-heterocycle (HC) compounds having various aromatic π-electron systems (Ar), such as phenyl, naphthyl, furyl, thienyl and phenanthryl moieties, and converted them as ligands to difluoroboronated complexes, Ar@HCs. Blue fluorescence from Ar@HCs was observed in solution and the solid state, and the fluorescence quantum yields (Φf) and lifetimes (τf) were determined. The Φf values in CHCl3 were as small as 0.1 except for the phenanthrene derivatives (0.4-0.6). Observation of the triplet-triplet absorption upon laser flash photolysis of Ar@HCs in solution indicated that the fluorescence process competes with intersystem crossing to the triplet state. Blue fluorescence in the solid state was observed with the Φf values of 0.3-0.7. Based on the crystallographic data, the relationship between the crystal structures and emission features of Ar@HCs in the solid state is discussed..
6. Motonori Watanabe, Kenta Goto, Takaaki Miyazaki, Masahiko Shibahara, Yuan Jay Chang, Tahsin J. Chow, Tatsumi Ishihara, Electrocatalytic hydrogen production using[FeFe]-hydrogenase mimics based on tetracene derivatives, New Journal of Chemistry, 10.1039/c9nj02790d, 43, 35, 13810-13815, 2019.01, The synthesis, structure, physical properties, and electrocatalytic hydrogen production of tetrathiatetracene ligand based[FeFe]-hydrogenase mimic molecules were investigated. By adjusting the amount of iron, mono- A nd bis-[FeFe] coordinated complexes 1 and 2 were synthesized. The structures of 1 and 2 were analysed by NMR, IR, and absorption spectroscopies, and cyclic voltammetry and DFT computational analysis. In the DFT electron density maps, the HOMOs and LUMOs were located at tetrathiatetracene units, indicating that these complexes retain mainly acene characteristics. When weak acid Et3NHBF4 was added to CH2Cl2 solutions of 1 or 2, the reduction potential of iron complexes was shifted to more positive values proportional to the concentration of acid. As the acid concentration increased, the current of the reduction wave also increased, indicating the occurrence of a catalytic proton reduction reaction. The bulk electrolysis reaction showed 65.8 TON for 1 and 52.8 TON for 2..
7. Koushi Yoshihara, Masamichi Yamanaka, Shuhei Kanno, Soichi Mizushima, Junko Tsuchiyagaito, Kazuki Kondo, Takahiro Kondo, Daichi Iwasawa, Hiroaki Komiya, Akira Saso, Shogo Kawaguchi, Kenta Goto, Shuhei Ogata, Hiromi Takahashi, Ayumi Ishii, Miki Hasegawa, Europium amphiphilic naphthalene based complex for the enhancement of linearly polarized luminescence in Langmuir-Blodgett films, New Journal of Chemistry, 10.1039/c8nj03976c, 43, 17, 6472-6479, 2019.01, Linearly polarized luminescence (LPL) in films of europium ions was induced by using naphthoic acid adopted alkyl chain (NaphC15), which plays the roles of both surfactant and photo-antenna. The synthesis of NaphC15 was newly developed, and the Eu complex composed in a 1:3 ratio of Eu3+ ion and NaphC15 was synthesized in the powder form for comparison. The structural aspects of LB films with a layered scheme were obtained from the measurements of synchrotron XRPD, X-ray photoelectron spectroscopy and waveguide polarized absorption spectra. Luminescence of europium in the film is more intense than that in the powdered complex. The luminescence efficiency calculated from the observed luminescence lifetimes and quantum yields also supported their structure-enhanced luminescence. Finally, we revealed that the LPL was sensitized by the electronic dipole moment localized on the NaphC15 moieties aligned independently in the Langmuir-Blodgett films..
8. Minoru Yamaji, Hideki Okamoto, Kenta Goto, Shin ichiro Kato, Fumito Tani, Yosuke Nakamura, Synthesis of isomeric coumarin-fluorene hybrids by photocyclization and the photophysical features, Tetrahedron Letters, 10.1016/j.tetlet.2018.02.033, 59, 13, 1216-1219, 2018.03, We prepared isomeric compounds 2a and 2b having fused skeletons of coumarin and fluorene by photochemical cyclization of olefin 1. They were successfully separated by chromatography, and characterized by NMR spectroscopic and X-ray crystallographic analyses. The molecular structure of 2a was nonplanar due to the repulsion between the carbonyl group of the coumarin moiety and the methylene group at 9-position on the fluorene skeleton whilst that of 2b was planar. They showed different absorption and fluorescence features in solution whereas their spectral profiles of triplet–triplet absorption and phosphorescence were similar to each other..
9. Ryotaro Fujii, Md Awlad Hossain, Hisato Akimoto, Kazunori Hirabayashi, Toshio Shimizu, Kazuhiko Akiyama, Kenta Goto, Hiroyuki Nishikawa, Ken Ichi Yamashita, Ken Ichi Sugiura, Synthesis of Tetra(3-thienyl)biphenoquinone and its Charge Transfer Complex with Perylene, Asian Journal of Organic Chemistry, 10.1002/ajoc.201700560, 7, 1, 171-178, 2018.01, Tetra(thienyl)biphenoquinones were designed and synthesized. An oxidative coupling of 2,6-bis(3-thienyl)phenol with PbO2 in acetic acid afforded the corresponding biphenoquinone along with 2,6-bis(3-thienyl)-p-benzoquinone. This biphenoquinone showed properties characteristic of a π-expanded quinone, that is, positively shifted reduction potential and light absorption in the visible region. In contrast to kinetically protected biphenoquinones with bulky substituents at the ortho-positions of carbonyls, the title compounds take a planar structure because of the small steric repulsion of the five-membered thiophene rings. Its charge transfer complex with perylene is characterized by a well-overlapped mixed stack..
10. Shuhei Ogata, Naoto Goto, Shoya Sakurai, Ayumi Ishii, Miho Hatanaka, Koushi Yoshihara, Ryota Tanabe, Kyosuke Kayano, Ryo Magaribuchi, Kenta Goto, Miki Hasegawa, Alkyl chain elongation and acyl group effects in a series of Eu/Tb complexes with hexadentate π-electronic skeletons and their enhanced luminescence in solutions, Dalton Transactions, 10.1039/c7dt04899h, 47, 21, 7135-7143, 2018.01, Five Eu complexes with long alkyl chain groups, abbreviated as EuLCx ("x" indicates the number of methylene groups: x = 8, 12, 14, 18, and 22), were synthesized to evaluate their structural and luminescence properties in chloroform. The mother helicate Eu complex, EuL, which has two bipyridine moieties bridged by an ethylenediamine, has been previously reported. A reduced form in which the azomethine groups of L also coordinated to the Eu ion, EuLH, was newly prepared. EuLH also adopts a helicate molecular structure based on single crystal X-ray structural analysis. The amine hydrogens of the bridging ethylenediamine of LH are active sites for substitution and were exchanged with five different alkyl chains to form EuLCx. Luminescence band positions and shapes of EuLCx in chloroform were completely identical, with a quantum yield of 37.1 ± 1.2 and a lifetime of around 1.25 ms. This indicates that the environments surrounding the Eu ion in the various complexes are all similar. Luminescence quantum yields of TbLH and TbLC18 are also strengthened, 48.7% in acetonitrile and 55% in chloroform, respectively. Potential energy surfaces were also described by using density functional theory, suggesting the possibility of a 1:2 complex of Eu and the ligand as a main luminescent species in solutions. This 1:2 complexation forms Eu-oxygen coordination using acyl groups. It indicates that the acyl group modification results in a different structure from the mother complexes..
11. Keita Tani, Toru Yashima, Kanae Miyanaga, Kazushige Hori, Kenta Goto, Fumito Tani, Yume Habuka, Katsuaki Suzuki, Katsuyuki Shizu, Hironori Kaji, Carbazole and benzophenone based twisted donoracceptor systems as solution processable green thermally activated delayed fluorescence organic light emitters, Chemistry Letters, 10.1246/cl.180438, 47, 9, 1236-1239, 2018.01, New donor-acceptor (D-A) and donor-acceptor-donor (D-AD) systems with carbazole and benzophenone moieties as donor and acceptor, respectively, have been synthesized. Photolumi-nescence quantum yields of D-A and D-A-D molecules in thin film were 76 and 73%, respectively. Solution-processed organic light-emitting diodes containing these D-A and D-A-D molecules as emitters showed the maximum external quantum efficiencies of 6.9 and 10.4% with a peak wavelength of 520 and 521 nm, respectively..
12. Minoru Yamaji, Shin Ichiro Kato, Kazuhiro Tomonari, Michitaka Mamiya, Kenta Goto, Hideki Okamoto, Yosuke Nakamura, Fumito Tani, Blue Fluorescence from BF2 Complexes of N,O-Benzamide Ligands
Synthesis, Structure, and Photophysical Properties, Inorganic Chemistry, 10.1021/acs.inorgchem.7b02013, 56, 20, 12514-12519, 2017.10, Small molecules having intense luminescence properties are required to promote biological and organic material applications. We prepared five types of benzamides having pyridine, pyridazine, pyrazine, and pyrimidine rings and successfully converted them into three types of the difluoroboronated complexes, Py@BAs, as novel blue fluorophores. Py@BA having a pyridine moiety (2-Py@BA) showed no fluorescence in solution, whereas Py@BAs of pyridazine and pyrazine moieties (2,3-Py@BA and 2,5-Py@BA, respectively) emitted blue fluorescence with quantum yields of ca. 0.1. Transient absorption measurements using laser flash photolysis of the Py@BAs revealed the triplet formation of 2,3- and 2,5-Py@BAs, while little transient signal was observed for 2-Py@BA. Therefore, the deactivation processes from the lowest excited singlet state of fluorescent 2,3- and 2,5-Py@BAs consist of fluorescence and intersystem crossing to the triplet state while that of the nonfluorescent Py@BA is governed almost entirely by internal conversion to the ground state. Conversely, in the solid state, 2-Py@BA emitted intense fluorescence with a fluorescence quantum yield as high as 0.66, whereas 2,3- and 2,5-Py@BAs showed fluorescence with quantum yields of ca. 0.2. The crystal structure of 2-Py@BA took a herringbone packing motif, whereas those for 2,3- and 2,5-Py@BAs were two-dimensional sheetlike. On the basis of the difference in crystal structures, the emission mechanism in the solid state was discussed..
13. Shohei Tomita, Kazunori Hirabayashi, Toshio Shimizu, Kenta Goto, Ken ichi Sugiura, Basic Photophysical Properties of meso-Bis(pyren-2-yl)porphyrin
An Isomer of Pyrene-Substituted Porphyrins, Synthesis, 10.1055/s-0036-1588715, 49, 10, 2182-2186, 2017.05, The Suzuki-Miyaura coupling reaction of pyren-2-yl boronic acid ester with a meso-dibromodiphenylporphyrin derivative was carried out to give another pyrene-substituted porphyrin. The electrophilic substitution reaction occurred selectively on the porphyrin nucleus of this molecule. The introduced pyrenes acted as a light-harvesting antenna..
14. Md Awlad Hossain, Ken Ichi Yamashita, Kazunori Hirabayashi, Toshio Shimizu, Kenta Goto, Ken Ichi Sugiura, Thiophene-Fused Dinaphthopentaphenes
Versatile Applications of 1,2-Bis(pyren-2-yl)aromatics in the Synthesis of π-Expanded Molecules, ChemistrySelect, 10.1002/slct.201700152, 2, 16, 4343-4348, 2017.01, Thiophene-fused dinaphtho[8,1,2-opq:2′,1′,8′-uva]pentaphenes (DNPPs) were synthesized and characterized by using our previously reported strategy. The Suzuki-Miyaura coupling of the boronic acid ester of pyrene with dibromothiophenes, 2,3-dibromo- and 3,4-dibromothiophenes, afforded the corresponding bis(pyren-2-yl)thiophenes. The subsequent oxidation reaction afforded the desired π-expanded molecules. Reflecting the DNPP moieties, the obtained molecules show properties characteristic of π-expanded molecules, such as amphoteric multiredox behaviors and light absorption in the visible region. The oxidized product of 3,4-bis(pyren-2-yl)thiophene, which contains an ortho-quinoidal structure, i. e., benzo[c]thiophene, was isolated and spectroscopically characterized. Because these molecules possess the [5]helicene structure, optical resolution of enantiomers has been carried out using high-performance liquid chromatography..
15. Tani, Keita, Kato, Haruka, Sakata, Naoya, Yashima, Toru, Kubono, Koji, Hori, Kazushige, Tao, Keisuke, K. Goto, 谷 文都, Takemura, Hiroyuki, Sakakibara, Keita, Tsujii, Yoshinobu, Synthesis and Radical Polymerization of Acrylamides Having One or Two 3-Carbazolylmethyl Moieties and Properties of the Formed Polymers, CHEMISTRY LETTERS, 10.1246/cl.160899, 46, 1, 85-87, 2017.01.
16. Masahiko Shibahara, Motonori Watanabe, Takaaki Miyazaki, Kenta Goto, Taisuke Matsumoto, Teruo Shinmyozu, Synthesis of Dibromo[33]paracyclophanes, Synthesis (Germany), 10.1055/s-0035-1560421, 48, 8, 1197-1201, 2016.03, All possible pseudogeminal-, pseudoortho-, pseudometa-, and pseudopara-dibromo[3.3]paracyclophanes were synthesized by the (p-tolylsulfonyl)methyl isocyanide (TosMIC) coupling method, and characterized by the aromatic proton signals of the 1H NMR spectra and finally by the X-ray crystal structure analyses of the pseudogeminal, pseudo-?ortho, and pseudopara isomers..
17. Md. A. Hossain, K. Akiyama, K. Goto, K.-i. Sugiura, Thermal reductive disproportionation of 3,3',5,5'-tetraphenyldiphenoquinone with drastic color change: Potential prototype of data storage advanced materials, ChemistySelect, 2016, 1, 3784-3790, 2016.01.
18. M. Watanabe, N. Uemura, S. Ida, H. Hagiwara, K. Goto, T. Ishihara, 5,5'-alkylsubsituted indigo for solution-processed optoelectronic devices, Tetrahedron, 2016, 72, 4280-4287., 2016.01.
19. V. L. Mishra, T. Furuyama, N. Kobayashi, K. Goto, T. Miyazaki, J.-S. Yang, T. Shinmyozu, Synthesis, Optical Properties, and Electronic Structures of Tetrakis(pentafluoro-phenyl)tetrathiaisophlorin Dioxide, Chem. Eur. J. , 2016, 22, 9190-9197., 2016.01.
20. M. Shibahara, M. Watanabe, T. Miyazaki, K. Goto, T. Shinmyozu, Synthesis of Dibromo[3.3]paracyclophanes, Synthesis-Stuttgart, 2016, 48, 1197-1201., 2016.01.
21. Motonori Watanabe, Naoki Uemura, Shintaro Ida, Hidehisa Hagiwara, Kenta Goto, Tatsumi Ishihara, 5,5′-alkylsubsituted indigo for solution-processed optoelectronic devices, Tetrahedron, 10.1016/j.tet.2016.05.069, 72, 29, 4280-4287, 2016.01, A series of alkylated indigos were synthesized. Alkylated indigos were characterized by NMR, mass spectrometry, absorption spectra, cyclic voltammetry, and density functional theory (DFT) calculations. Propyl and butyl group substituted indigo was most soluble in chloroform and 1,2-dicrolobenzene, and these solubility were 65–89 times increased as compared to the parent indigo. DFT calculations suggested that the presence of the alkyl chains at the 5.5′-position increases the energy of the highest occupied molecular orbital, while reducing the energy of the lowest unoccupied molecular orbital. This theoretical finding was in good agreement with the experimental results. Crystal structures obtained by X-ray diffraction showed one-dimensional pi–pi stacking. Alkylated molecules were converted to leuco structure, and these structures were then converted to the corresponding indigos in the film state. After deposition of the films on TiO2/FTO substrate, oxidative photocurrents were observed..
22. Vijay Lakshmi Mishra, Taniyuki Furuyama, Nagao Kobayashi, Kenta Goto, Takaaki Miyazaki, Jye Shane Yang, Teruo Shinmyozu, Synthesis, Optical Properties, and Electronic Structures of Tetrakis(pentafluorophenyl)tetrathiaisophlorin Dioxide, Chemistry - A European Journal, 10.1002/chem.201505079, 22, 27, 9190-9197, 2016.01, The synthesis, structure, optical and redox properties, and electronic structure of tetrakis(pentafluorophenyl)tetrathiaisophlorin dioxide (12) are reported. Oxidation of tetrakis(pentafluorophenyl)tetrathiaisophlorin (11) with dimethyldioxirane afforded the oxidized product, which was the tetrathiaisophlorin with two thiophene 1-oxide moieties (12). More significant nonplanarity and greater bond length alternation in 12 than those of 11 were observed by X-ray structural analysis. The absorption spectrum of 12 contains two bands at λ=348 and 276 nm, with a weak tail that extends to λ≈650 nm. Analysis of the magnetic circular dichroism spectrum of 12, based on Michl's 4N-perimeter model and molecular orbital calculations, indicate that the broad band at λ=348 nm appears to contain N2and P2bands, and 12 is classified as a 4nπ system, similar to 11. The nuclear-independent chemical shift values and1H NMR spectroscopy data indicate that 12 has more antiaromatic character than 11..
23. Md Awlad Hossain, Kazuhiko Akiyama, Kenta Goto, Ken Ichi Sugiura, Thermal reductive disproportionation of 3,3′,5,5′-tetraphenyldiphenoquinone with drastic color change
Potential prototype of data storage advanced materials, ChemistrySelect, 10.1002/slct.201600437, 1, 13, 3784-3790, 2016.01, The solid-state thermal reaction of brilliant red 3,3′,5,5′-tetraphenyldiphenoquinone 1 was examined. Three reductive colorless products, the corresponding hydroquinone and two benzofuran derivatives, were formed at 289.5 °C. Theoretical studies indicated that thermally excited triplet species having radical-type oxygen atoms participated in the reaction. Single-crystal diffraction study revealed short atomic contacts between carbonyl oxygen and the ortho-positions of the phenyl group, and these short atomic contacts would promote the thermal solid-state reaction. The reductive reactions observed in cumene, a radical propagation solvent and/or a hydrogen radical donating solvent, supported our speculation..
24. Md Ershad Halim, Arkasish Bandyopadhyay, Liansheng Sun, Keisuke Tao, Yogesh Shashikant Sangvikar, Takaaki Miyazaki, Motonori Watanabe, Keiko Ideta, Taisuke Matsumoto, Kenta Goto, Teruo Shinmyozu, Synthesis of bromo- and iodo-substituted pyromellitic diimide-based [2+2]- and [3+3]macrocycles, and their absorption spectra and electrochemical and inclusion properties, Tetrahedron Letters, 10.1016/j.tetlet.2015.10.070, 56, 50, 6970-6974, 2015.12, New pyromellitic diimide-based tetrabromo[2+2]macrocycle ([2+2]MC) 2, tribromo- and hexabromo[3+3]MCs 3a and 3b, as well as triiodo[3+3]MC 3c were synthesized as structural units of covalently bound nanotubes, and their absorption spectra and redox properties, as well as inclusion phenomena of the [2+2]MC 2 were reported. Tetrabromo[2+2]MC 2 forms a 1:1 inclusion complex with toluene, whose structure was revealed by X-ray structural analysis..
25. Motonori Watanabe, Ching-Ting Chien, Yan-Duo Lin, Yuan Jay Chang, Yuh-Sheng Wen, Kenta Goto, Masahiko Shibahara, Teruo Shinmyozu, Tahsin J. Chow, Synthesis, physical properties, and structure of TIPS-difuranoacenes, Tetrahedron Letters,, 2014, 55, 1424–1427, 2015.02.
26. Md. E. Halim, A. Bandyopadhyay, L.-S. Sun, K. Tao, Y. S. Sangvikar, T. Miyazaki, M. Watanabe, K. Ideta, T. Matsumoto, K. Goto, Teruo Shinmyozu, Synthesis of bromo- and iodo-substituted pyromellitic diimide-based [2+2]- and [3+3]macrocycles, and their absorption spectra and electrochemical and inclusion properties, Tetrahedron Letters, 2015, 56, 6970-6974., 2015.10.
27. Masahiko Shibahara, Motonori Watanabe, Kenta Goto, Takaaki Miyazaki, Hua Zhang, Yuki Nakayama, Teruo Shinmyozu, Structural properties of five- and six-layered [3.3]metacyclophanes, Tetrahedron Letters, 10.1016/j.tetlet.2014.10.151, 55, 51, 7089-7093, 2014.12, We performed X-ray structural analyses of the five- and six-layered [3.3]metacyclophanes (MCPs) 1 and 2 and the six-layered [3.3]MCP tetraone 3. In the solid state, the MCP moieties of 1, 2, and 3 adopt different conformations from those of the free MCPs in solution. In the five-layered [3.3]MCP 1, all the [3.3]MCP moieties adopt anti (chair/boat) conformations. In the six-layered [3.3]MCP 2, two three-layered [3.3]MCPs are connected by a [3.3]MCP in the anti conformation with completely parallel benzene rings. In the six-layered [3.3]MCP tetraone 3, the outer [3.3]MCP moieties and diones adopt general syn and anti geometries, respectively. However, the inner [3.3]MCP moiety adopts an anti geometry. Based on density functional theory (DFT) calculations, the most stable conformers of 1, 2, and 3 are syn (chair/chair) in the [3.3]MCP moieties and anti (twist boat/twist boat) in the dione moieties..
28. Takaaki Miyazaki, Masahiko Shibahara, Jun Ichi Fujishige, Motonori Watanabe, Kenta Goto, Teruo Shinmyozu, Synthesis and electronic and photophysical properties of [2.2]- and [3.3]paracyclophane-based donor-donor′-acceptor triads, Journal of Organic Chemistry, 10.1021/jo5020273, 79, 23, 11440-11453, 2014.12, Three types of the donor(D)-donor′(D′)-acceptor(A) triads 1-6 with different D-A combinations, carbazole (Cz, D)-[n.n]PCP(D′)-1,8-naphthalimide (NI, A) (1-3), 10H-phenothiazine (PTZ, D)-[n.n]PCP(D′)-NI(A) (4, 5), and 10-methyl-10H-phenothiazine (Me-PTZ, D)-[2.2]PCP-2,1,3-benzothiadiazole (BTD, A) 6, were synthesized for the elucidation of their photophysical properties. The absorption spectra and electrochemical properties indicated that the chromophores (D, D′, and A) do not interact with each other in the ground state. Cz-(CH2)3-[2.2]PCP-(CH2)3-NI 1 and Cz-(CH2)3-[3.3]PCP-(CH2)3-NI 2 show an exciplex emission between the PCP and NI moieties in cyclohexane and the intensity of the band is much higher in 2 than in 1, whereas Cz-(CH2)2-[2.2]PCP-(CH2)2-NI 3 does not show any exciplex emission in cyclohexane. These results indicated that the combination of [3.3]PCP and a trimethylene chain is preferable for the exciplex formation. PTZ-(CH2)3-[2.2]PCP-(CH2)3-NI 4 shows a broad band at 519 nm in cyclohexane, which is associated with the formation of the exterplex band among the NI, [2.2]PCP, and PTZ moieties, while PTZ-(CH2)3-[3.3]PCP-(CH2)3-NI 5 does not show the band. Me-PTZ-(CH2)2-[2.2]PCP-(CH2)2-BTD 6 shows a broad fluorescence band due to both the BTD and PTZ moieties in cyclohexane. In CH3CN, the fluorescence spectra of 1-6 suggest the presence of a photoinduced charge separation process. The study of the photoinduced charge separation process will be soon reported elsewhere..
29. M. Shibahara, M. Watanabe, T. Matsumoto, K. Goto, T. Shinmyozu, Crystal structure of a four-layered [3.3](3,5)pyridino-phane, Acta Crystallographica Section E, 2014, 70, 447-450, 2014.11.
30. Masahiko Shibahara, Motonori Watanabe, Taisuke Matsumoto, Kenta Goto, Teruo Shinmyozu, Crystal structure of a four-layered [3.3](3,5)pyridinophane, Acta Crystallographica Section E: Structure Reports Online, 10.1107/S1600536814023691, 70, 11, 447-450, 2014.10, The title compound, C40H46N2 {systematic name: 12,30-diazaheptacyclo[,19.16,18.110,14.124,36.128,32]dotetraconta-1(37),5(40),6(41),10(42),11,13,18,23,28,30,32(39),36(38)-dodecaene}, has syn-anti-syn geometry wherein the two outer [3.3]metacyclophane (MCP) moieties have a syn geometry, and contain the facing benzene and pyridine rings at dihedral angles of 26.26 (10) and 26.46 (10)°, respectively. The rings of the central [3.3]MCP unit are not parallel, but orientated at a slight angle of 2.66 (9)°. Three bridging methylene groups are disordered over two sets of sites in a 0.60:0.40 ratio. In the crystal, the molecules are linked by C - H⋯N interactions and intermolecular C - H⋯π short contacts, generating a three-dimensional network..
31. Yuki Matsunaga, Kenta Goto, Koji Kubono, Katsuya Sako, Teruo Shinmyozu, Photoinduced color change and photomechanical effect of naphthalene diimides bearing alkylamine moieties in the solid state, Chemistry - A European Journal, 10.1002/chem.201304849, 20, 24, 7309-7316, 2014.06, Photoinduced color change of naphthalene diimides (NDIs) bearing alkylamine moieties has been observed in the solid state. The color change is attributed to the generation of a NDI radical-anion species, which may be formed through a photoinduced electron-transfer process from the alkylamine moiety to the NDI. The photosensitivity of NDIs is highly dependent on the structures of the alkylamine moieties. Crystallographic analysis, kinetic analysis, UV/Vis/NIR spectroscopic measurements, and analysis of the photoproduct suggested that a radical anion was formed through an irreversible process initiated by proton abstraction between an amine radical cation and the neutral amine moiety. The radical anions formed stacks including mixed-valence stacks and radical-anion stacks, as shown by the broad absorption bands in near-IR spectra. These photosensitive NDIs also showed crystal bending upon photoirradiation, which may be associated with a change in the intermolecular distance of the NDI stacks by the formation of monomeric radical anions, mixed-valence stacks, and radical-anion stacks..
32. Masahiko Shibahara, Motonori Watanabe, Kenta Goto, Teruo Shinmyozu, Four-layered [3.3]metacyclophane with ethenetetracarbonitrile, Acta Crystallographica Section E: Structure Reports Online, 10.1107/S1600536814009362, 70, 5, o625-o626, 2014.05, The title complex C42H48·2C6N 4 {systematic name: heptacyclo[,19.1 6,18.110,14.124,36.128,32] dotetraconta-1(37),5(40),6(41),10(42),11,13,18,23,28,30,32(39),36(38) -dodecaene-ethenetetracarbonitrile (1/2)}, consisting of four-layered [3.3]metacyclophane (MCP) with two tetracyanoethylene (TCNE) molecules, was grown from a mixture of MCP and TCNE in chloroform solution. The four-layered [3.3]MCP has an S-shaped structure in which three [3.3]MCP moieties take syn-(chair-boat), anti-(chair-boat) and syn-(chair-boat) conformations. The two outer [3.3]MCP moieties with syn geometry contain benzene rings with a tilt of 32.95(7)°. The central [3.3]MCP moiety has an anti geometry, in which the two benzene rings are oriented parallel to each other at a transannular distance of 2.31Å. The TCNE molecules are stacked on either side of the outer [3.3]MCP units at a distance of 3.19Å on one side and 3.24Å on the other, and showed 0.80:0.20 and 0.44:0.56 disorder, respectively..
33. Ohyama, Kazuko; Goto, Kenta; Shinmyozu, Teruo; Yamamoto, Norifumi; Iizumi, Shota; Miyagawa, Masaya; Nakata, Munetaka; Sekiya, Hiroshi, Infrared spectroscopic studies on 4-amino-6-oxopyrimidine in a low-temperature Xe matrix and crystalline polymorphs composed of double hydrogen-bonded ribbons, Chemical Physics Letters, 10.1016/j.cplett.2014.01.059, 595, 138-143, 2014, 595-596, 138-143., 2014.03.
34. Motonori Watanabe, Ching Ting Chien, Yan Duo Lin, Yuan Jay Chang, Yuh Sheng Wen, Kenta Goto, Masahiko Shibahara, Teruo Shinmyozu, Tahsin J. Chow, Synthesis, physical properties, and structure of TIPS-difuranoacenes, Tetrahedron Letters, 10.1016/j.tetlet.2014.01.036, 55, 8, 1424-1427, 2014.02, The synthesis, physical properties, and structure of triisopropylsilylethynyltetracenodifuran (2) and pentacenodifuran (3) derivatives were reported. There showed high stability in solution in the dark, yet decomposed under light. Single crystal of pentacenodifuran was analyzed by X-ray diffraction analysis, and showed one dimensional packing array along the c-axis. The molecules were stacked with a 3.30 Å interlayer distance. The crystals exhibited a high thermal stability under an ambient condition..
35. Takahisa Uchise, Kenta Goto,* Aya Harano and Teruo Shinmyozu*, Selective alcohol adsorption in a uniformly ordered array of lipophilic mesopores by a giant macrocycle, RSC Advances, DOI: 10.1039/c3ra45716h, 4, 6014-6018, 2014.01.
36. Kuo, Chi-Hsien; Huang, Ding-Chi; Peng, Wei-Tao; Goto, Kenta; Chao, Ito; Tao, Yu-Tai, Substituent effect on the crystal packing and electronic coupling of tetrabenzocoronenes: a structure-property correlation, JOURNAL OF MATERIALS CHEMISTRY C, 10.1039/c4tc00296b, 2, 20, 3928-3935, 2014, 2, 3928-3925., 2014.01.
37. Y. Matsunaga, K. Goto, K. Kubono, K. Sako, and T. Shinmyozu , Photoinduced Color Change and Photomechanical Effect of Naphthalene Diimides Bearing Alkylamine Moieties in the Solid State, Chemistry - A European Journal, 2014, 20, 7309-7316., 2014.01.
38. M. Shibahara, M. Watanabe, K. Goto, T. Shinmyozu, Four-layered [3.3]metacyclophane with ethenetetracarbonitrile, Acta Crystallographica Section E, 2014, 70, o625-o626., 2014.01.
39. Takahisa Uchise, Kenta Goto, Aya Harano, Teruo Shinmyozu, Selective alcohol adsorption in a uniformly ordered array of lipophilic mesopores by a giant macrocycle, RSC Advances, 10.1039/c3ra45716h, 4, 12, 6014-6018, 2014.01, The crystal structure of giant macrocycle 1 was found to have a mesoporous structure. The lipophilic pores of 1 uniformly formed in an ordered array, and contributed to the selective adsorption of 1-BuOH among the isomers of butanol..
40. Masahiko Shibahara, Motonori Watanabe, Takaaki Miyazaki, Jun Ichi Fujishige, Yuki Matsunaga, Keisuke Tao, Zhang Hua, Kenta Goto, Teruo Shinmyozu, Synthesis, structure, and electronic and photophysical properties of donor–acceptor cyclophanes, Organic Structure Design Applications in Optical and Electronic Devices, 95-136, 2014.01.
41. Koji Kubono, Keita Tani, Kunihiko Yokoi, Teruo Shinmyozu, Kenta Goto, Di-μ2-acetato-1:2κ2 O:O′;2
3κ2 O:O′-bis{μ2-4,4′-dichloro-2, 2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato} -1:2κ6 O,N,N′,O′:O,O′;2:3κ6 O,O′:O,N,N′,O′-tricadmium, Acta Crystallographica Section E: Structure Reports Online, 10.1107/S1600536813029413, 69, 12, m629-m630, 2013.12, In the title linear homo-trinuclear complex, [Cd3(C 19H18Cl2N2O2)2(C 2H3O2)2], the central CdII atom is located on a centre of inversion and has a distorted octahedral coordination geometry formed by four O atoms from two bidentate/tetradentate Schiff base ligands and two O atoms from two bridging acetate ligands. The coordination geometry of the terminal CdII atom is square-pyramidal with the tetradentate part of the ligand in the basal plane and one O atom from an acetate ligand occupying the apical site. The six-membered CdN2C 3 ring adopts a chair conformation. The acetate-bridged Cd⋯Cd distance is 3.3071 (2) Å. The crystal structure is stabilized by C-H⋯O hydrogen bonds, which form C(7) chain motifs and give rise to a two-dimensional supramolecular network structure lying parallel to the ab plane..
42. K. Kubono, K. Tani, K. Yokoi, T. Shinmyozu and K. Goto, Di-µ2-acetato-1:2κ2O:O';2:3κ2O:O'-bis{µ2-4,4'-dichloro-2,2'-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}-1:2κ6O,N,N',O':O,O';2:3κ6O,O':O,N,N',O'-tricadmium(II), Acta Crystallographica Section E, E69, m629-m630., 2013.10.
43. Motonori Watanabe, Yuan Jay Chang, Shun Wei Liu, Ting Han Chao, Kenta Goto, Md Minarul Islam, Chih Hsien Yuan, Yu Tai Tao, Teruo Shinmyozu, Tahsin J. Chow, The synthesis, crystal structure and charge-transport properties of hexacene, Nature Chemistry, 10.1038/nchem.1381, 4, 7, 574-578, 2012.07, Acenes can be thought of as one-dimensional strips of graphene and they have the potential to be used in the next generation of electronic devices. However, because acenes larger than pentacene have been found to be unstable, it was generally accepted that they would not be particularly useful materials under normal conditions. Here, we show that, by using a physical vapour-transport method, platelet-shaped crystals of hexacene can be prepared from a monoketone precursor. These crystals are stable in the dark for a long period of time under ambient conditions. In the crystal, the molecules are arranged in herringbone arrays, quite similar to that observed for pentacene. A field-effect transistor made using a single crystal of hexacene displayed a hole mobility significantly higher than that of pentacene. This result suggests that it might be instructive to further explore the potential of other higher acenes..
44. Motonori Watanabe, Yuan Jay Chang, Shun-Wei Liu, Ting-Han Chao, Kenta Goto, Md. Minarul Islam, Chih-Hsien Yuan, Yu-Tai Tao, Teruo Shinmyozu and Tahsin J. Chow, The synthesis, crystal structure and charge-transport properties of hexacene, Nature Chemistry, doi:10.1038/nchem.1381, Vol. 4, 574-578., 2012.06, [URL].
45. Koji Kubono, Teruo Shinmyozu, Kenta Goto, Tsuyoshi Tsujioka and Keita Tani, 1,2-Bis[5-(9-ethyl-9H-carbazol-3-yl)-2- methylthiophen-3-yl]-3,3,4,4,5,5-hexa- fluorocyclopentene, Acta Crystallographica Section E, E67, o2194., 2011.08.
46. Koji Kubono, Teruo Synmyouzu, Kenta Goto, Tsuyoshi Tsujioka, Keita Tani, 1,2-Bis[5-(9-ethyl-9H-carbazol-3-yl)-2-methyl-thio-phen-3-yl]-3,3,4,4,5, 5-hexa-fluoro-cyclo-pentene, Acta Crystallographica Section E: Structure Reports Online, 10.1107/S1600536811029539, 67, 8, o2194, 2011.08, The title compound, C 43H 32F 6N 2S 2, is a new symmetrical photochromic diaryl-ethene derivative with 9-ethyl-carbazol-3-yl substituents. The mol-ecule adopts a photoactive anti-parallel conformation [Irie (2000). Chem. Rev. 100, 1685-1716; Kobatake et al. (2002). Chem. Commun. pp. 2804-2805], with a dihedral angle between the mean planes of the two thio-phene rings of 56.23 (6)°. The distance between the two reactive C atoms is 3.497 (3) Å. In the crystal, two molecules are associated through a pair of C - H⋯F inter-molecular hydrogen bonds, forming a centrosymmetric dimer. Dimers are linked by weak π-π inter-actions [centroid-centroid distance = 3.8872 (13) Å], forming chains along the c axis..
47. Masahiko Shibahara, Motonori Watanabe, Chang Yuan, Kenta Goto, Teruo Shinmyozu, Structural properties of charge-transfer complexes of multilayered [3.3]paracyclophanes, Tetrahedron Letters, 10.1016/j.tetlet.2011.04.087, 52, 26, 3371-3375, 2011.06, In the solid state, multilayered [3.3]paracyclophanes (PCPs) 2-6 and tetracyanoethylene (TCNE) form charge-transfer (CT) complexes with a 1:1 stoichiometry. All the benzene rings overlapped each other. All the [3.3]PCP units and dione units assume chair conformations and the transannular distances are shorter than those of the corresponding free multilayered [3.3]PCP except for the dione unit in the four-layered dione 6. In the crystal-packing diagrams, the PCP and TCNE are located in alternating donor-acceptor stacking in columns, and effective short contacts are observed in the neighboring molecules..
48. Aya Harano, Minako Tanaka, Takeshi Nakagaki, Masahiko Annaka, Keiko Ideta, Kenta Goto, Teruo Shinmyozu, Changing the volume of a giant macrocycle
The swelling of the macrocycle with organic solvents, Organic and Biomolecular Chemistry, 10.1039/c1ob05272a, 9, 10, 3611-3614, 2011.05, The novel tetrahedral macrocycles 1a-1c have been synthesized. Macrocycles 1a and 1c were revealed to have the property to increase in volume in solution by complexation between the macrocycle and the solvent molecules..
49. Masahiko Shibahara, Motonori Watanabe, Chang Yuan, Kenta Goto, and Teruo Shinmyozu, Structural properties of charge-transfer complexes of multilayered [3.3]paracyclophanes, Tetrahedron Letters,, 52 (26) 3371-3375., 2011.04.
50. Aya Harano, Minako Tanaka, Takeshi Nakagaki, Masahiko Annaka, Keiko Ideta, Kenta Goto, Teruo Shinmyozu, Changing the volume of a giant macrocycle: the swelling of the macrocycle with organic solvents, Organic & Biomolecular Chemistry, DOI: 10.1039/c1ob05272a, 9 (10), 3611-3614, 2011.03.
51. T. Nakagaki, A. Harano, Y. Fuchigami, E. Tanaka, S. Kidoaki, Dr. T. Okuda, T. Iwanaga, K. Goto, T. Shinmyozu, Formation of Nanoporous Fibers by the Self-Assembly of a Pyromellitic Diimide-Based Macrocycle, Angewandte Chemie Internal Edition, 10.1002/anie.201004992, 49, (50), 9676-9679, 2010.12.
52. Y. Miyahara, K. Goto, and T. Inazu., ChemInform Abstract: Synthesis and Properties of a Novel Tetraazamacrocycle Containing Two Bispidine Units, ChemInform, 10.1002/chin.200044171, 31, 44, 2010.10.
53. Motonori Watanabe, Kenta Goto, Masahiko Shibahara, and Teruo Shinmyozu, Synthesis, Structure, and Electronic and Photophysical Properties of Two- and Three-Layered [3.3]Paracyclophane-Based Donor-Acceptor Systems, The Journal of Organic Chemistry, DOI: 10.1021/jo100688m, 75 (18) 6104-6114, 2010.10.
54. Motonori Watanabe, Kenta Goto, Mamoru Fujitsuka, Sachiko Tojo, Tetsuro Majima, and Teruo Shinmyozu, 2,1,3-Benzothiadiazole Dimers: Preparation, Structure, and Transannular Electronic Interactions of syn- and anti-[2.2](4,7)Benzothiadiazolophanes, Bulletin of the Chemical Society of Japan, doi:10.1246/bcsj.20100085, 83 (10), 1155-1161, 2010.10.
55. Motonori Watanabe, Kenta Goto, Mamoru Fujitsuka, Sachiko Tojo, Tetsuro Majima, Teruo Shinmyozu, 2,1,3-benzothiadiazole dimers
Preparation, structure, and transannular electronic interactions of syn-and anti-[2.2](4,7)benzothiadiazolophanes, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.20100085, 83, 10, 1155-1161, 2010.10, The cyclophanes comprised of two 2,1,3-benzothiadiazole (BTD) rings, anti-and syn-[2.2](4,7)benzothiadiazolophanes (anti-1 and syn-1), were prepared for the first time. The differences of the physical properties in the overlapping mode of the π-systems are clearly observed, and syn-1 shows much more significant transannular π-electronic interactions than anti-1 especially in the redox properties and the stability of the radical anion species..
56. Motonori Watanabe, Kenta Goto, Masahiko Shibahara, Teruo Shinmyozu, Synthesis, structure, and electronic and photophysical properties of two- and three-layered [3.3]Paracyclophane-based donor-acceptor systems (1), Journal of Organic Chemistry, 10.1021/jo100688m, 75, 18, 6104-6114, 2010.09, Figure presented. The synthesis, structural, redox, and photophysical properties of the two- and three-layered donor-acceptor (D-A) type [3.3]paracyclophanes ([3.3]PCPs) are described. The synthesis of the two- and three-layered [3.3]PCPs 1 and 2 containing 2,1,3-benzothiadiazole (BTD) as an acceptor was achieved by the (p-ethylbenzenesulfonyl)methyl isocyanide coupling method. The cyclic voltammograms of 1 and 2 along with those of respective dione precursors 5 and 7 clearly indicate that the presence of the -CH 2COCH2- bridge interferes with the electronic interactions between the BTD and the benzene rings, suggesting the importance of the through-bond interaction in the ground state. In sharp contrast, the UV/vis spectra of 1 and 5 as well as those of 2 and 7 exhibit similar bands regardless of the presence of the -CH2COCH2- or -CH 2CH2CH2- bridges, indicating that the charge-transfer (CT) interaction is mainly responsible for the through-space interaction. The two-layered PCPs, 5 and 1, show broad structureless fluorescence bands at the same position of 468 nm, while those of the three-layered PCPs, 7 and 2, appear at 501 and 496 nm, respectively, with lower quantum yields compared to those of the two-layered PCPs probably due to the stronger intramolecular CT interaction of the three-layered PCPs in the ground state..
57. N. Dixit, K. Goto, L. Mishra, H.W. Roesky, Supramolecular architectures constructed with the skeletons of zinc(II) 2,2'-bipyridine and barbiturate anion: Synthesis and characterization, Polyhedron, 20 (4), 1299-1304, 2010.03.
58. N. Dixit, K. Goto, L. Mishra, H. W. Roesky, Supramolecular architectures constructed with the skeletons of zinc(II) 2,2′-bipyridine and barbiturate anion
Synthesis and characterization, Polyhedron, 10.1016/j.poly.2010.01.010, 29, 4, 1299-1304, 2010.03, The barbiturate 1,5-dihydro-5-[5-pyrimidine-2,4(1H,3H)-dionyl]-2H-chromeno[2,3-d] pyrimidine-2,4(3H)-dione) (LH4) 1 forms a complex with Zn(bpy)(NO3)2·2H2O (bpy = 2,2′-bipyridine) of composition [Zn(bpy)2(H2O)2]2+·(LH3)2·7H2O (2). In this structure, the ligand exists as anion (LH3-) as revealed by its single crystal X- ray crystallographic study. Packing studies of 2 provide three dimensional helical chains as secondary structure. However, its PXRD pattern shows that 2 does not retain its structure upon dehydration. Recrystallization of 2 from DMSO results in complex 3 with the composition [Zn(bpy)2(H2O)2]2+·(LH3-)2·DMSO·9H2O assigned on the basis of its elemental analysis and its X-ray crystallography. In order to understand the role of the 2,2′-bipyridine ring in the construction of supramolecular architecture, the reaction of zinc(II) nitrate salt with 1 is carried out to provide complex 4 of composition [Zn(LH3)2(H2O)4]·4H2O characterized by its single crystal X-ray diffraction study. Thermal, emission and photoluminescence properties of the complexes are also studied..
59. Kenta Goto, Yuji Miyahara, Teruo Shinmyozu, A spherical molecular assembly formed by the interplay of hydrophobic and hydrogen bonding interactions. Formation of a hexameric ball, Tetrahedron Letters, 10.1016/j.tetlet.2009.12.012, 51, 5, 832-835, 2010.02, A six-membered ball-like supramolecular structure of 1c was obtained by the interplay of hydrophobic and hydrogen bonding interactions. Preferred H-bonding connectivity and the proximate side-chain groups in a hydrophobic core stabilized to form the ball structure as revealed by making a comparison with the linear tape structure in the crystal polymorph of 1c..
60. Kenta Goto, Yuji Miyahara, and Teruo Shinmyozu, A Spherical Molecular Assembly Formed by the Interplay of Hydrophobic and Hydrogen Bonding Interactions. Formation of a Hexameric Ball, Tetrahedron Letters,, 51, 5, 832-835, 2010.01, [URL].
61. Shin-ichiro Kato, Yasuhiro Nonaka, Toshiaki Shimasaki, Kenta Goto, Teruo Shinmyozu., Novel pyromellitic diimide-based macrocycle with a linear pi-electronic system and bis(phenylethynyl)pyromellitic diimide: Syntheses, structures, photophysical properties, and redox characteristics, The Journal of Organic Chemistry, 73, 4063-4075., 2008.06.
62. Shin Ichiro Kato, Yasuhiro Nonaka, Toshiaki Shimasaki, Kenta Goto, Teruo Shinmyozu, Novel pyromellitic diimide-based macrocycle with a linear π-electronic system and bis(phenylethynyl)pyromellitic diimide
Syntheses, structures, photophysical properties, and redox characteristics, Journal of Organic Chemistry, 10.1021/jo800283r, 73, 11, 4063-4075, 2008.06, (Chemical Equation Presented) We report the syntheses, structures, photophysical properties, and redox characteristics of the [2 + 2] pyromellitic diimide-based macrocycle with a linear π-electronic system 2 as well as the 3,6-bis(phenylethynyl)pyromellitic diimide derivative 3. The interesting solid state structural properties of the clathrates of 3 with π-donors are also reported. The macrocycle 2 was synthesized by the direct cyclocondensation followed by the Sonogashira coupling reaction. X-ray crystallographic studies showed that the phenylacetylene moieties in 2 formed the intramolecular benzene dimer structures, and the bis(phenylethynyl)pyromellitic diimide moieties in both 2 and 3 were stacked in a parallel and slanted arrangement. Theoretical calculations for 2′ and 3 suggested the existence of electrostatic interactions between the bis(phenylethynyl)pyromellitic diimide moieties. The UV/vis spectral measurements and TDDFT calculations of 2, 2′, and/or 3 were performed to understand their electronic transitions. The fluorescence spectral measurements showed that 2 and 3 have visible fluorescence properties and 2 displays an excimer fluorescence at ca. 590 nm. The cyclic voltammetry measurements revealed that the electrostatic repulsion between the diimide moieties in 2 is greater than that in 1 according to the extension of the π-electronic systems. X-ray crystallography of the clathrates of 3 with various π-donors demonstrated the formation of the segregated donor-acceptor structures, indicating the strong aggregation ability of the bis(phenylethynyl)pyromellitic diimide moiety..
63. Kenta Goto, Rieko Omae, Minoru Yamaji, Teruo Shinmyozu, J-type aggregation of a simple merocyanine skeleton
Spectral features and structure of 4-amino-6-oxopyrimidine, Journal of Photochemistry and Photobiology A: Chemistry, 10.1016/j.jphotochem.2007.07.019, 194, 1, 92-96, 2008.02, The absorption and fluorescence spectral properties of 4-amino-6-oxopyrimidine (1), which has a simple streptopolymethine merocyanine skeleton, clearly showed that the molecule 1 formed the aggregate 1n, and showed an exciton band, appearing at an absorption of 350 nm due to the red-shifted HOMO-LUMO transition. Upon light irradiation of the exciton band, a fluorescence band at 398 nm (ΦFL = 0.10) was observed, and its decay lifetimes were determined. Based on these spectral features, the aggregated 1n was found to be formed by J-type aggregation. The molecular orientation 1 in the crystal was revealed as being both parallel π-π stacking and hydrogen bonding chains..
64. Eva Ingrid Rõõm, Agnes Kütt, Ivari Kaljurand, Ivar Koppel, Ivo Leito, Ilmar A. Koppel, Masaaki Mishima, Kenta Goto, Yuji Miyahara, Bronsted basicities of diamines in the gas phase, acetonitrile, and tetrahydrofuran, Chemistry - A European Journal, 10.1002/chem.200700097, 13, 27, 7631-7643, 2007.10, A comprehensive basicity study of α,ω-alkanediamines and related bases has been carried out. Basicities in acetonitrile (AN, pK a values), tetrahydrofuran (THF, pkα values), and gas phase (GP, GB values), were measured for 16, 14, and 9 diamine bases and for several related monoamines. In addition the gas-phase basicities and equilibrium geometries were computed for 19 diamino bases and several related monoamines at the DFT B3LYP 6-311+G** level. The effects of the different factors (intrinsic basicity of the amino groups, formation of intramolecular hydrogen bonds, and molecular strain) determining the diamine basicities were estimated by using the method of isodesmic reactions. The results are discussed in terms of molecular structure and solvation effects. The GP basicity is determined by the molecular size and polarizability, the extent of alkylation, and the energy effect of intramolecular hydrogen bond formation in the protonated base. The basicity trends in the solvents differ very much from those in GP: 1)The solvents severely compress the basicity range of the bases studied (3.5 times for the 1,3-propanediamine family in AN, and 7 times in THF), and 2) while stepwise alkylation of the basicity center leads to a steady basicity increase in the gas phase, the picture is complex in the solvents. Significant differences are also evident between THF and AN. The high hydrogen bond acceptor strength of THF leads to this solvent favoring the bases with "naked" protonation centers. In particular, the basicity order of N-methylated 1,3-propanediamines is practically inverse to that in the gas phase. The picture in AN is intermediate between that of GP and THF..
65. Kenta Goto and Teruo Shinmyozu, Regulated Formation of 2D Water Layers with Alternating Six-membered Quasi-planar and Chair Cluster Units by 1D Supramolecular Chain, Chemistry Letters, 36, 1100-1101., 2007.09.
66. E.-I. Rõõm, A. Kütt, I. Kaljurand, I. Koppel, I. Leito, I.-A. Koppel, M. Mishima, K. Goto, and Y. Miyahara, Brønsted Basicities of Diamines in the Gas Phase, Acetonitrile, and Tetrahydrofuran, Chemistry - A European Journal, 13(27), 7631-7643., 2007.09.
67. Kenta Goto, Temo Shinmyozu, Regulated formation of 2D water layers with alternating six-membered quasi-planar n and chair cluster units by ID supramolecular chain, Chemistry Letters, 10.1246/cl.2007.1100, 36, 9, 1100-1101, 2007.09, Crystals of 4-methylamino-6-oxopyrimidine (1) grown from aqueous alcohol were found to contain 2D water layers consisting of hexameric water clusters with alternating quasiplanar and chair conformations, which are apparently regulated by interactions with the supramolecular aggregate of 1n through hydrogen bonds..
68. Toshiaki Shimasaki, Shin-ichiro Kato, Keiko Ideta, Kenta Goto, and Teruo Shinmyozu, Synthesis and structural and photoswitchable properties of novel chiral host molecules: Axis chiral 2,2'-dihydroxy-1,1'-binapththyl-appended stiff-stilbene, The Journal of Organic Chemistry, 72 (4), 1073-1087., 2007.04.
69. Toshiaki Shimasaki, Shin Ichiro Kato, Keiko Ideta, Kenta Goto, Teruo Shinmyozu, Synthesis and structural and photoswitchable properties of novel chiral host molecules
Axis chiral 2,2′-dihydroxy-1,1′-binaphthyl-appended stiff-stilbene, Journal of Organic Chemistry, 10.1021/jo061127v, 72, 4, 1073-1087, 2007.02, (Chemical Equation Presented) Novel photoswitchable chiral hosts having an axis chiral 2,2′-dihydroxy-1,1′-binaphthyl (BINOL)-appended stiff-stilbene, trans-(R,R)- and -(S,S)-1, were synthesized by palladium-catalyzed Suzuki-Miyaura coupling and low-valence titanium-catalyzed McMurry coupling as key steps, and they were fully characterized by various NMR spectral techniques. The enantiomers of trans-1 showed almost complete mirror images in the CD spectra, where two split Cotton effects (exciton coupling) were observed in the β-transitions of the naphthyl chromophore at 222 and 235 nm, but no Cotton effect was observed in the stiff-stilbene chromophore at 365 nm. The structures of (R)-10 and trans-(R,R)-1 were confirmed by X-ray structural analysis. The optimized structure of cis-1 by MO calculations has a wide chiral cavity of 7-8 Å in diameter, whereas trans-1 cannot form an intramolecular cavity based on the X-ray data. Irradiation of (R,R)-trans-1 with black light (λ = 365 nm) in CH3CN or benzene at 23°C led to the conversion to the corresponding cis-isomer, as was monitored by 1H NMR, UV - vis, and CD spectra. At the photostationary state, the cis-1/ trans-1 ratio was 86/14 in benzene or 75/25 in CH3CN. On the other hand, irradiation of the cis-1/trans-1 (75/25) mixture in CH3CN with an ultra-high-pressure Hg lamp at 23°C (λ = 410 nm) led to the photostationary state, where the cis-1/trans-1 ratio was estimated to be 9/91 on the basis of the 1H NMR spectra. The cis-trans and trans-cis interconversions could be repeated 10 times without decomposition of the C=C double bond. Thus, a new type of photoswitchable molecule has been developed, and trans-1 and cis-1 were quite durable under irradiation conditions. The guest binding properties of the BINOL moieties of trans- and cis-(R,R)-1 with F -, Cl-, and H2PO4- were examined by 1H NMR titration in CDCl3. Similar interaction with F- and Cl- was observed in trans-1 (host/guest = 1/1, Kassoc = (1.0 ± 0.13) × 103 for F - and (4.6 ± 0.72) × 102 M-1 for Cl-) and cis-1 (host/guest = 1/1, Kassoc = (1.0 ± 0.13) × 103 for F- and (5.9 ± 0.69) × 10 M-1 for Cl-), but H2PO4 - interacted differently: the cis-isomer formed the 1/1 complex (Kassoc = (9.38 ± 2.67) × 10 M-1), whereas multistep equilibrium was expected for the trans-isomer..
70. Shin Ichiro Kato, Taisuke Matsumoto, Keiko Ideta, Toshiaki Shimasaki, Kenta Goto, Teruo Shinmyozu, Supramolecular assemblies and redox modulation of pyromellitic diimide-based cyclophane via noncovalent interactions with naphthol, Journal of Organic Chemistry, 10.1021/jo0600196, 71, 13, 4723-4733, 2006.06, This paper reports the electroscopic and electrochemical properties of [2 + 2] pyromellitic diimide-based cyclophane 1 as well as acyclic N,N′-bis(2-methoxybenzyl)pyromellitic diimide 2 and the clathrate compounds formed by 1. Compound 1 was synthesized by direct cyclocondensation. Its structure was determined by an X-ray crystallographic analysis of a single crystal obtained by recrystallization from DMF. The intramolecular charge-transfer interactions of 1 and 2 were characterized by UV/vis spectroscopy and MO calculations. The UV/vis spectra showed that the tail of a longer wavelength absorption of both 1 and 2 reached the visible region. MO calculations (B3LYP/6-31G*) showed that the HOMO and LUMO orbitals of 1 and 2 substantially localize in the xylyl and pyromellitic diimide moieties across the methylene linker, respectively. The X-ray crystallographic analyses demonstrated that single crystals grown from a mixture of 1 and α-naphthol and a mixture of 1 and β-naphthol were the clathrate compounds with 1D and 2D supramolecular assemblies, respectively, which are formed by a combination of hydrogen-bonding and charge-transfer interactions. From the cyclic voltammetry measurements, both 1 and 2 showed reversible reduction processes, and the reduction potential observed at -1.09 V vs Ag/Ag+ for 2 split into two potentials at -1.01 and -1.14 V for 1. The addition of α- and β-naphthol induced a decrease in the potentials due to the diradical anion of 1 and radical anion of 2 by about 80 mV, and their reduction processes were reversible..
71. Shin-ichiro Kato, Taisuke Matsumoto, Keiko Ideta, Toshiaki Shimasaki, Kenta Goto, and Teruo Shinmyozu, Supramolecular assemblies and redox modulation of pyromellitic diimide-based cyclophane via noncovalent interactions with naphthol, The Journal of Organic Chemistry, 71(13), 4723-4733., 2006.04.
72. M. Umemiya, K. Goto, S. Takaishi, H. Miyasaka, K. I. Sugiura, M. Yamashita, H. Nishikawa, K. Kikuchi, I. Ikemoto, Y. Yokochi, H. Ito, S. Kuroda, New organic conductor (DMET)2CuCl2
Synthesis, structure and physical properties, ISCOM 2003: 5th International Symposium on Crystalline Organic Metals, Superconductors and Ferromagnets Journal De Physique. IV : JP, 10.1051/jp4:2004114140, 114, 589-590, 2004.12, A new organic conducting salt, (DMET)2CuCl2, was prepared by a diffusion method, crystal and electrical structures of which were investigated. The single-crystal X-ray crystallography revealed that DMET molecules are alternately stacked to form quasi-one-dimensional (Q-1D) columns. This salt exhibited a metallic behavior with lowering temperature σRr = 1.25 × 103 S-cm-1), where several resistance jumps were observed..
73. Y. Miyahara, K. Goto, M. Oka, and T. Inazu., Remarkably Facile Ring-Size Control in Macrocyclization: Synthesis of Hemicucurbit[6]uril and Hemicucurbit[12]uril, Angewandte Chemie International Edition, 10.1002/anie.200460764, 43, 38, 5019-5022, 43(38), 5019-5022, 2004.01.
74. M. Umemiya, K. Goto, S. Takaishi, H. Miyasaka, K.-i. Sugiura, M. Yamashita, H. Nishikawa, K. Kikuchi, I. Ikemoto, Y. Yokochi, H. Ito and S. Kuroda, New organic conductor (DMET)2CuCl2: Synthesis, structure and physical properties, J. Phys. IV France, 114, 589-590., 2004.01.
75. V. Galasso, K. Goto, Y. Miyahara, B. Kovac, and L. Klasinc., On the structure and spectroscopic properties of bispidine, N,N-dimethyl-bispidine and a bis-bispidine macrocycle, Chemical Physics, 10.1016/S0301-0104(02)00331-2, 277, 3, 229-240, 277, 229-240, 2002.01.
76. Yuji Miyahara, Kenta Goto, Takahiko Inazu, Erratum
A novel hindered macrocyclic tetramine containing two bispidine units. A new type of proton sponge (Tetrahedron Letters (2001) 42 (3097-3099) PII S0040403901003410)), Tetrahedron Letters, 10.1016/S0040-4039(01)02014-7, 42, 51, 2001.12.
77. Y. Miyahara, K. Goto, T. Inazu, Convenient synthesis of 3,7-diazabicyclo[3.3.1]nonane (bispidine), Synthesis, 3, 364-366, 2001.03, Bispidine 1a is conveniently synthesized via a route involving double Mannich reaction of 1-allylpiperidin-4-one to N,N′-diallylbispidinone, Wolff-Kishner reduction of the bispidinone, and deallylation of the resulting N,N′-diallylbispidine by treatment with ethyl chloroformate in the presence of NaI, followed by alkaline hydrolysis..
78. Y. Miyahara, K. Goto, and T. Inazu., A novel hindered macrocyclic tetramine containing two bispidine units. A new type of proton sponge, Tetrahedron Letters, 10.1016/S0040-4039(01)00341-0, 42, 17, 3097-3099, 42, 3097-3099, 2001.01.
79. T. Nishida, K. Goto, S. Kubuki, T. Tamaki, 57Fe Mossbauer, XRD and DTA study of the crystallization behavior of calcium aluminate glass containing iron(III), Journal of Radioanalytical and Nuclear Chemistry, 10.1023/A:1006764510701, 246, 1, 51-56, 2000.10, 57Fe Mossbauer spectroscopy was applied to the crystallization study of IR-transmitting calcium aluminate glass, 60CaO·32Al2O3·5Fe2O3·3Eu2O3, in which Fe(III) atoms occupy tetrahedral Al(III) sites. Heat treatment of calcium aluminate glass below and above the crystallization temperature causes the formation of mayenite, 12CaO·7Al2O3, and brownmillerite, 4CaO·Al2O3·Fe2O3, respectively. Mossbauer spectra of the glass ceramics indicate that Fe(III) atoms substitute Al(III) sites, having less covalent Fe(III)-O bonds and more distorted Fe(III)O4 tetrahedra than they do in the original glass. DTA revealed that crystallization of calcium aluminate glass is triggered by simultaneous cleavage of Ca-O and Al-O bonds..
80. Y. Miyahara, K. Goto, and T. Inazu., Synthesis and Properties of a Novel Tetraazamacrocycle Containing Two Bispidine Units, Chemistry Letters, 10.1246/cl.2000.620, 6, 620-621, 620-621, 2000.01.
81. T. Nishida, K. Goto, S. Kubuki, and T. Tamaki., 57Fe Mossbauer, XRD and DTA study of the crystallization behavior of calcium aluminate glass containing iron(III), Journal of Radioanalytical and Nuclear Chemistry, 246, 51-56, 2000.01.
82. M. Shibahara, M. Watanabe, K. Goto, T. Miyazaki, T. Shinmyozu, Structural properties of five- and six-layered [3.3]metacyclophanes, Tetrahedron Letters, 2014, 55, 7089-7093.
83. T. Miyazaki, M. Shibahara, J. Fujishige, M. Watanabe, K. Goto, T. Shinmyozu, Synthesis and Electronic and Photophysical Properties of [2.2]- and [3.3]Paracyclophane-Based Donor-Donor'-Acceptor Triads, Journal of Organic Chemistry, 2014, 79, 11440-11453.