Misc - 奥野　恒久

22aPS-92 かごめ格子反強磁性体m-R PYNN・Xの^1H-NMR

藤井 裕, 後藤 喬雄, 小山田 明, 山口 明, 奥野 恒久, 藤田 渉, 阿波賀 邦夫

日本物理学会講演概要集 ( 一般社団法人日本物理学会 )  55 ( 2 ) 352 - 352   2000年09月

24pS-7 かごめ格子有機反磁性体m-AlkylPYNN塩の^1Hの核磁気共鳴II

藤井 裕, 後藤 喬雄, 小山田 明, 阿波賀 邦夫, 山口 明, 奥野 恒久

日本物理学会講演概要集 ( 一般社団法人日本物理学会 )  54 ( 2 ) 342 - 342   1999年09月

28p-E-10 カゴメ格子有機磁性体m-AlkylPYNN^+・X^-の^1Hの核磁気共鳴

藤井 裕, 後藤 喬雄, 小山田 明, 阿波賀 邦夫, 山口 明, 奥野 恒久

日本物理学会講演概要集 ( 一般社団法人日本物理学会 )  54 ( 1 ) 406 - 406   1999年03月

25a-PS-136 有機分子磁性体m-AlkylPYNN^+・X^-の^1Hの核磁気緩和

藤井 裕, 後藤 喬雄, 小山田 明, 阿波賀 邦夫, 山口 明, 奥野 恒久

日本物理学会講演概要集 ( 一般社団法人日本物理学会 )  53 ( 2 ) 480 - 480   1998年09月

Crystal structures and magnetic properties of acid-base molecular complexes, (p-pyridyl nitronylnitroxide)(2)X (X = hydroquinone, fumaric acid and squaric acid)

T Otsuka, T Okuno, K Awaga, T Inabe

JOURNAL OF MATERIALS CHEMISTRY ( ROYAL SOC CHEMISTRY )  8 ( 5 ) 1157 - 1163   1998年05月

　概要を見る

The reactions of 2-(4-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl 3-N-oxide (or p-pyridyl nitronylnitroxide, abbreviated as p-PYNN) with the three dibasic organic acids, X[= fumaric acid (FA), squaric acid (SA) and hydroquinone (HQ)], result in the formation of hydrogen-bonding complexes of (p-PYNN)(2) . X composition. In their crystals, the organic acids make selective hydrogen bonds to the two kinds of hydrogen-bond accepting sites in p-PYNN; (a) the oxygen atom in the NO group and (b) the nitrogen atom of the pyridyl ring. p-PYNN2 . HQ crystallizes in the monoclinic P2(1)/n space group. The HQ molecule bridges two p-PYNNs, and selects site (a) in p-PYNN as the hydrogen bond acceptor [i.e. (p-PYNN)NO ... HO(HQ)OH ... ON(p-PYNN)]. p-PYNN2 . FA crystallizes in the monoclinic P2(1)/n space group. The FA molecule connects two p-PYNN molecules with an intermolecular hydrogen bond to site (b) [(p-PYNN)N ... HO(FA)OH ... N(p-PYNN)]. The 2:1 compound of p-PYNN and SA crystallizes with the crystal solvent, 1,4-dioxane (abbreviated as diox), in the formula for p-PYNN2 . SA . diox. The crystal belongs to the triclinic <P(1)over bar> space group. The SA molecule occupies the space between two p-PYNNs, making contact with site (b), as FA does in the p-PYNN2 . FA crystal. However the structure of SA indicates that it is a dianion in which the two protons are missing and, thus, the hydrogen bond is ionic [(p-PYNN)NH+... O-(SA)O-... H+N(p-PYNN)]. The selectivity and features of the hydrogen bonds can be qualitatively understood in terms of competition between the electrostatic and charge-transfer terms in the hydrogen-bonding energy, which is governed by the acidity of the organic acids and the proton accepting abilities of the two sites in p-PYNN. The three molecular compounds exhibited different antiferromagnetic properties, which depend on the mutual arrangement of p-PYNN in the crystals. The intermolecular interactions were interpreted based on the McConnell's spin polarization mechanism.

DOI

30a-PS-46 有機分子磁性体m-MPYNN^+・X^-(X=ClO_4,BF_4)塩の超低温における^1Hの核磁気緩和II

藤井 裕, 小山田 明, 後藤 喬雄, 佐々木 豊, 水崎 隆雄, 阿波賀 邦夫, 奥野 恒久, 山口 明

日本物理学会講演概要集 ( 一般社団法人日本物理学会 )  53 ( 1 ) 378 - 378   1998年03月

28a-N-3 有機分子磁性体m-MPYNN^+・X^-(X=CIO_4, BF_4)塩の超低温における ^1Hの核磁気緩和

藤井 裕, 後藤 喬雄, 佐々木 豊, 水崎 隆雄, 阿波賀 邦夫, 奥野 恒久

日本物理学会講演概要集 ( 一般社団法人日本物理学会 )  52 ( 1 ) 398 - 398   1997年03月

28a-N-2 μSRから見た2次元カゴメ有機磁性体m-MPYNN・BF_4の基底状態

渡邊 功雄, 和田 信雄, 矢野 英雄, 山口 明, 奥野 恒久, 阿波賀 邦男, 大平 聖子, 西山 樟生, 永嶺 謙忠

日本物理学会講演概要集 ( 一般社団法人 日本物理学会 )  52   398 - 398   1997年

DOI

有機分子磁性体m-MPYNN^+X^-(X=ClO_4, BF_4)塩の^1Hの核磁気緩和II

藤井 裕, 後藤 喬雄, 佐々木 豊, 水崎 隆雄, 阿波賀 邦夫, 奥野 恒久

日本物理学会講演概要集. 秋の分科会 ( 一般社団法人日本物理学会 )  1996 ( 3 ) 60 - 60   1996年09月

31a-YE-5 有機分子磁性体m-MPYNN^+X^-(X=ClO_4,BF_4)塩の^1Hの核磁気緩和(磁性(低次元系))

藤井 裕, 後藤 喬雄, 阿波賀 邦夫, 奥野 恒久

日本物理学会講演概要集. 年会 ( 一般社団法人日本物理学会 )  51 ( 3 ) 15 - 15   1996年03月

Coexistence of intermolecular ferromagnetic interaction and [NHN] + hydrogen bond in N-protonated m-pyridyl nitronyl nitroxide

Tsunehisa Okuno, Takeo Otsuka, Kunio Awaga

Journal of the Chemical Society, Chemical Communications   ( 8 ) 827 - 828   1995年

　概要を見る

Reaction of 2-(3-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1- oxyl 3-N-oxide (m-PYNN) and HBr gas gives rise to the complex (m-PYNN) 2HBr, in which the coexistence of an intermolecular ferromagnetic interaction and an [NHN]+ hydrogen bond is found.

DOI

POSSIBLE REENTRANT BEHAVIOR IN MAGNETIC-PROPERTIES OF TBA[FE(TDAS)(2)] COMPLEX

K AWAGA, T OKUNO, Y MARUYAMA, A KOBAYASHI, H KOBAYASHI, S SCHENK, AE UNDERHILL

INORGANIC CHEMISTRY ( AMER CHEMICAL SOC )  33 ( 24 ) 5598 - 5600   1994年11月

DOI

MAGNETOSTRUCTURAL CORRELATION IN A SERIES OF IODIDE SALTS OF P-N-ALKYLPYRIDINIUM NITRONYL NITROXIDES - DEPENDENCE OF THE IODIDE-PYRIDINIUM RING INTERACTION ON THE LENGTH OF THE N-ALKYL CHAIN

K AWAGA, A YAMAGUCHI, T OKUNO, T INABE, T NAKAMURA, M MATSUMOTO, Y MARUYAMA

JOURNAL OF MATERIALS CHEMISTRY ( ROYAL SOC CHEMISTRY )  4 ( 9 ) 1377 - 1385   1994年09月

　概要を見る

Magnetic measurements and X-ray crystal analyses were carried out on iodide salts of p-N-alkylpyridinium a-nitronyl nitroxides [4-(4,4,5,5-tetramethyl-1-oxido-3-oxyl-4,5-dihydro-3H-imidazol-2'yl)-1-R-pyridinium, with R = methyl (1(+)), ethyl (2(+)), n-propyl (3(+)) and n-butyl (4(+))]. The strongly antiferromagnetic crystal of 1(+).l(-) consists of a radical dimer and the iodide ion is out of the plane of the pyridinium ring. 2(+).l(-), which is weakly antiferromagnetic, includes two crystallographically independent molecules, 2A(+) and 2B(+), each of which forms a centrosymmetric dimer. in the pyridinium ring of 2A(+) the iodides are 'out-of-plane' while for 2B(+) they are 'in-plane'. The ferromagnetic 3(+).l(-) and 4(+).l(-) have similar structures: the crystal consists of a two-dimensional (2D) layer formed by a contact between the pyridinium ring and in-plane iodides. In this series, the iodide ion changes position from out-of-plane to in-plane and the magnetism varies from antiferromagnetic to ferromagnetic. It is found that the nitronyl nitroxide with an out-of-plane iodide has a short intermolecular contact between the NO groups (type I), while that with an in-plane iodide forms a contact between the NO group and the pyridinium ring (type II). The observed magnetic behaviour can be interpreted in terms of an antiferromagnetic interaction for the type I contact and a ferromagnetic interaction for type II.

DOI

Variable magnetic interactions in an organic radical system of (m-N-methylpyridinium α-nitronyl nitroxide)X-: A possible kagomé antiferromagnet

Kunio Awaga, Tsunehisa Okuno, Akira Yamaguchi, Morikuni Hasegawa, Tamotsu Inabe, Yusei Maruyama, Nobuo Wada

Physical Review B   49 ( 6 ) 3975 - 3981   1994年

　概要を見る

In this paper we study an organic system of geometrical spin frustration. m-N-methylpyridinium α-nitronyl nitroxide (m-MPYNN+) is a spin-1/2 organic radical. The simple salt, m-MPYNN+ClO4-1/3 (acetone), crystallizes in a trigonal P3c1 space group, where the m-MPYNN+ molecules exist as a dimer and the dimer units form a two-dimensional (2D) triangular lattice. One-third of the C1O4- ions are in the organic layer, joining the m-MPYNN+ molecules, and the remainder is between the layers, compensating the excess of positive charge in the organic layers. The single-crystal EPR measurements clearly indicate a 2D Heisenberg character of the magnetic system in it. m-MPYNN+ makes a crystalline solid-solution system, m-MPYNN+(ClO4-)xI1-x-1/3 (acetone) (0≤x≤1), which also belongs to the trigonal system. Both the a and c axes are slightly lengthened with increasing the ratio of the C1O4- ion, x, in the solid solution: The unit-cell volume is increased by 3.2% when x runs from 0 to 1. The temperature dependence of the magnetic susceptibilities of the solid solutions can be well interpreted in terms of a strong ferromagnetic intradimer interaction J1 forming a triplet state and a weak antiferromagnetic interdimer interaction J2 which is expected to give rise to spin frustration among the triplet spin species on each side of the triangles. It is found that J2 quickly weakens with an increase in x, while J1 shows little dependence. There is a possibility that this organic system can be characterized as a spin-1 kagomé antiferromagnet at very low temperatures. © 1994 The American Physical Society.

DOI

液晶性ジアセチレンのネマティック相重合挙動

奥野恒久、菅原正、泉岡明

  226,201   1993年

非対称アリール置換ジアセチレンの結晶構造と反応性

  225,393   1993年

KINETIC FEATURE OF NEMATIC PHASE POLYMERIZATION OF DIACETYLENES

A IZUOKA, T OKUNO, T ITO, T SUGAWARA, N SATO, S KAMEI, K TOHYAMA

MOLECULAR CRYSTALS AND LIQUID CRYSTALS ( GORDON BREACH SCI PUBL LTD )  226   201 - 205   1993年

　概要を見る

Nematic phase polymerization of diacetylenes proceeded without an induction period. The decay rate of monomers was found to be enhanced in a thin film sample. When an external electric field was applied to the thin film, the rate was accelerated with a threshold value of 2500 V/cm which corresponds to that for a dynamic scattering mode.

CRYSTAL-STRUCTURE AND SOLID-STATE REACTIVITY OF UNSYMMETRICALLY ARYL-SUBSTITUTED DIACETYLENE

T OKUNO, A IZUOKA, K KUME, N SATO, T SUGAWARA

MOLECULAR CRYSTALS AND LIQUID CRYSTALS ( GORDON BREACH SCI PUBL LTD )  225   393 - 398   1993年

　概要を見る

Novel unsymmetrically aryl-substituted diacetylene derivative (1), 4'-(5''-hydroxy-1'',3''-pentadiynyl)benzylidene-p-anisidine, was prepared. Reactivity of polymerization of 1 in the solid state was discussed based on its crystal structure revealed by an X-ray diffraction method.

CRYSTAL-STATE AND LIQUID-CRYSTAL STATE POLYMERIZATION OF UNSYMMETRICAL DIACETYLENES WITH AN ORIENTATION-CONTROLLING SUBSTITUENT

T OKUNO, M FUKADA, A IZUOKA, N SATO, T SUGAWARA

MOLECULAR CRYSTALS AND LIQUID CRYSTALS ( TAYLOR & FRANCIS LTD )  216-18   59 - 64   1992年

液晶性配向制御部位の導入によるジアセチレンの結晶相・液晶相重合反応

  217,59   1992年