Published Papers - OKUNO Tsunehisa

1-Ethyl-4-(1H-naphtho[1,8-de][1,3,2]diazaborinin -2(3H)-yl)pyridin-1-ium Iodide

Shu Hashimoto, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrdata   9   x240362   2024.03  [Refereed]

1-Ethyl-4-(1H-naphtho[1,8-de][1,3,2]diazaborinin -2(3H)-yl)pyridin-1-ium Iodide monohydrate

Shu Hashimoto, Shintaro Miki, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrdata   9   x240369   2024.03  [Refereed]

Hydrated polymorphs of 2,3,4,5,6-pentachlorobenzoic acid: Crystallographical and computational analyses of disordered hydrogen-bonding networks

Tsunehisa Okuno, Koji Ozaki, Iori Higashino （Part： Lead author,　Corresponding author )

Journal of Molecular Structure   1276   134815   2023.01  [Refereed]

10-[(4-Nitrophenyl)ethynyl]-10H-phenothiazine

Tsunehisa Okuno, Ikue Doi （Part： Lead author,　Corresponding author )

IUCrData   7   x220942   2022.09  [Refereed]

DOI

N-Phenyl-N-[(E)-2-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)ethenyl]aniline

Yuki Hatayama, Kazuto Akagi, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrData   7   x220083 - x220083   2022.01  [Refereed]

9-[(Z)-2-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)ethenyl]-9H-carbazole

Mayu Kanagawa, Kazuto Akagi, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrData ( International Union of Crystallography (IUCr) )  6 ( 2 ) x210142 - x210142   2021.02  [Refereed]

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The title compound, C₂₀H₂₂BNO₂, has a polarized π-system due to resonance between N—C(H)=C(H)—B and ionic N⁺=C(H)—C(H)=B⁻ canonical structures. The dihedral angles between the ethenyl plane (r.m.s. deviation for C₂H₂ = 0.0333 Å) with the ethenyl-<italic>C</italic>(NC₂-pyrrole) plane (r.m.s. deviation CNC₂ 0.0423 Å) and the ethenyl-C(BO₂-1,3,2-dioxaborolane) plane (r.m.s. deviation BCO₂ 0.0082 Å) are 45.86 (8) and 37.47 (8)°, respectively, and are greater than those found for the previously reported <italic>E</italic>-isomer [Hatayama &amp; Okuno (2012) <italic>Acta Cryst.</italic> E<bold>68</bold>, o84]. In comparison with the <italic>E</italic>-isomer, the reduced planarity of <italic>Z</italic>-isomer results in a decrease of the contribution of the N⁺=C(H)—C(H)=B⁻ canonical structure.

DOI

Crystal structure and DFT study of N-(6-(diphenylamino)pyridin-2-yl)-N-phenylacetamide

Tomoka Okuda, Satoru Umezono, Tsunehisa Okuno （Part： Last author,　Corresponding author )

Журнал структурной химии ( NIIC SB RAS )  60 ( 3 ) C.412 - C.414   2019.05  [Refereed]

DOI

A triclinic polymorph of N-[5-(diphenylamino)penta-2,4-diyn-1-yl]benzamide

Koji Ozaki, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrData ( International Union of Crystallography (IUCr) )  4 ( 4 ) x190371 - x190371   2019.03  [Refereed]

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The title compound, C₂₄H₁₈N₂O, was been described previously in the space group <italic>P</italic>2₁/<italic>c</italic> with <italic>Z</italic> = 4 [Kawashima &amp; Okuno (2017). <italic>IUCrData</italic>, <bold>2</bold>, x170277]. The current <italic>P</italic>\overline{1} polymorph was obtained from a chloroform–ethanol solution. The molecular structure in this polymorph is slightly different from the previously reported structure, with different dihedral angles of the two <italic>N</italic>-phenyl groups to the ynamine plane; these are 79.99 (11) and 12.09 (11)° in the polymorph reported here. The molecules form dimers through four C—H...π interactions. Furthermore, in this polymorph, the molecules stack along the <italic>a</italic> axis to form a molecular arrangement that would be suitable to promote the solid-state polymerization of diacetylenes.

DOI

3-(4-Iodophenyl)pentanedinitrile

Yuuki Nanpo, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrData ( International Union of Crystallography (IUCr) )  4 ( 2 ) x190282 - x190282   2019.02  [Refereed]

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In the title pentanedinitrile derivative, C₁₁H₉IN₂, the iodophenyl group is connected at the 3-position. The central propylene chain of the pentanedinitrile moiety contains one <italic>gauche</italic> conformation as a result of steric repulsion with the phenyl ring. Intermolecular close contacts in the crystal comprise a weak C<italic>sp</italic>
³—H...N hydrogen bond and a C—I...N halogen bond.

DOI

Crystal polymorphs and ab initio calculation of 2,3,4,5,6-pentachlorobenzoic acid

Koji Ozaki, Tsunehisa Okuno （Part： Last author )

Journal of Molecular Structure ( Elsevier BV )  1173   959 - 963   2018.12  [Refereed]

DOI

Crystal polymorphs of 6-[(phenylcarbamoyl)oxy]hexa-2,4-diyn-1-yl isonicotinate

Ryo Yamamoto, Shoma Minami, Tsunehisa Okuno （Part： Last author,　Corresponding author )

Acta Crystallographica Section C Structural Chemistry ( International Union of Crystallography (IUCr) )  74 ( 8 ) 876 - 881   2018.08  [Refereed]

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The title compound, C₁₉H₁₄N₂O₄, was found to have two crystal polymorphs, in which the molecular structures of the diacetylenic compound are broadly similar. The main structural difference between the polymorphs concerns the intermolecular hydrogen-bonding motifs adopted, namely a one-dimensional zigzag polymer linked by N—H...N(py) (py is pyridine) interactions in polymorph I and a centrosymmetric dimeric motif formed by N—H...O=C interactions in polymorph II. The diacetylene cores of the molecules stack along the <italic>a</italic> and <italic>b</italic> axes in polymorphs I and II, respectively. It was found that only the molecular arrangement in polymorph II satisfies Baughman's criterion to afford polydiacetylenes (PDAs) by thermal annealing or irradiation with light. This predicted polymerization activity was confirmed by experiment.

DOI

5-[Phenyl(pyridin-4-yl)amino]penta-2,4-diyn-1-ol

Satoru Umezono, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrData ( International Union of Crystallography (IUCr) )  3 ( 3 ) x180454 - x180454   2018.03  [Refereed]

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In the title diacetylene derivative, C₁₆H₁₂N₂O, the amino plane makes dihedral angles of 3.90 (4) and 60.53 (4)°, respectively, with the pyridyl and phenyl rings, indicating that an electron-deficient pyridyl ring makes better conjugation with a lone pair of the amino nitrogen atom. In the crystal, molecules form inversion dimers<italic>via</italic>pairs of hydrogen bonds between the hydroxy and pyridyl groups, with an O...N distance of 2.7765 (16) Å. The dimers stack along the<italic>a</italic>axis, but the title compound shows little solid-state polymerization reactivity.

DOI

10-[1,1-Dichloro-4-(trimethylsilyl)but-1-en-3-yn-2-yl]-10H-phenothiazine

Satoru Umezono, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrData ( International Union of Crystallography (IUCr) )  3 ( 2 ) x180232 - x180232   2018.02  [Refereed]

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The title compound, C₁₉H₁₇Cl₂NSSi, is an enamine derivative, in which the N atom adopts a shallow trigonal–pyramidal geometry [displacement from the plane of its attached C atoms = 0.1383 (18) Å]. The dihedral angle between the plane through the three amino carbon atoms and the vinyl group is 89.47 (7)°. The phenothiazine unit has a butterfly structure and the central six-membered ring adopts a boat conformation. The fold angle between the benzene rings is 28.52 (7)°. The crystal structure features weak C<italic>sp</italic>³—H...Cl hydrogen bonds, H...S contacts and π–π stacking interactions between phenothiazine units.

DOI

Conformational polymorphs of a novel TCNQ derivative carrying an acetylene group

Yuki Iida, Makoto Kataoka, Tsunehisa Okuno （Part： Last author,　Corresponding author )

Journal of Molecular Structure ( Elsevier BV )  1152   261 - 265   2018.01  [Refereed]

DOI

Systematic study of intermolecular C–X⋯O S (X = Cl, Br, I) halogen bonds in (E)-10-(1,2-dihalovinyl)-10H-phenothiazine 5,5-dioxides

Satoru Umezono, Tsunehisa Okuno （Part： Last author,　Corresponding author )

Journal of Molecular Structure ( Elsevier BV )  1147   636 - 642   2017.11  [Refereed]

DOI

N2,N2,N6,N6-Tetraphenylpyridine-2,6-diamine

Shintaro Miki, Satoru Umezono, Tsunehisa Okuno （Part： Last author,　Corresponding author )

IUCrData ( International Union of Crystallography (IUCr) )  2 ( 4 ) x170521 - x170521   2017.04  [Refereed]

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In the title compound, C₂₉H₂₃N₃, the molecule has an unsymmetrical structure, although it can possess<italic>Cs</italic>symmetry. The NC_{<italic>3</italic>}units around the amino N atoms are approximately planar and make dihedral angles of 13.41 (5) and 31.05 (5)° with the pyridine ring. In the crystal, C—H...N interactions between the phenyl and pyridyl rings lead to a columnar stack along the<italic>b</italic>axis.

DOI

N-[5-(Diphenylamino)penta-2,4-diyn-1-yl]benzamide

Takuya Kawashima, Tsunehisa Okuno （Part： Corresponding author )

IUCrData ( International Union of Crystallography (IUCr) )  2 ( 2 ) x170277 - x170277   2017.02

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In the title compound, C₂₄H₁₈N₂O₁, the ynamine moiety has a near-planar structure (r.m.s. deviation = 0.0200 Å), and makes dihedral angles of 52.99 (7) and 27.91 (7)° with the phenyl rings. In the crystal, the molecules exhibit a dimeric form owing to bifurcated C—H...π interactions within a centrosymmetric dimer. Intermolecular N—H...O hydrogen bonds are also formed along the<italic>b-</italic>axis direction.

DOI

Preparations, crystal structures and DFT calculation of diacetylene derivatives carrying nicotinic esters

Shoma Minami, Hirokazu Iwahashi, Tsunehisa Okuno （Part： Last author,　Corresponding author )

Journal of Molecular Structure ( Elsevier BV )  1108   438 - 443   2016.03  [Refereed]

DOI

Conformational polymorphs and solid-state polymerization of 9-(1,3-butadiynyl)carbazole derivatives

Hideyuki Tabata, Kazunori Kuwamoto, Tsunehisa Okuno （Part： Last author,　Corresponding author )

Journal of Molecular Structure ( Elsevier BV )  1106   452 - 459   2016.02  [Refereed]

DOI

Crystal structure and DFT study of N-phenyl-N-(pyridin-4-yl)acetamide

S. Umezono, T. Okuno （Part： Last author,　Corresponding author )

J. Struct. Chem   56   472 - 474   2015.07  [Refereed]