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| 1.
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Maruyama, Tatsuya ; Kikukawa, Yuji ; Sakiyama, Hiroshi ; Katayama, Misaki ; Inada, Yasuhiro ; Hayashi, Yoshihito ; 林, 宜仁
概要:
金沢大学理工研究域物質化学系<br />The structure transformation of multinuclear-metal-cores can change catalytic, optical, and magnetic
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properties. Cyclic decavanadate ligands exhibit versatility in the number and the direction of the coordination sites by changing the conformation to stabilize various multinuclear-metal-cores, while organic multinucleating ligands require specific design for each of the multimetal complexes due to their structure directing ability. The flexibility of cyclic decavanadate ligands is demonstrated here to achieve accommodation of dinuclear or trinuclear units by using the same ligand. The reaction of a dinuclear-cobalt-core-containing decavanadate [Co2(H2O)2V10O30]6- (Co2) with 1 equiv. of Co(OAc)2 (OAc = acetate) gave a trinuclear-cobalt-core-containing decavanadate [Co3(H2O)(OAc)V10O30]5- (Co3) in high yield. The central cobalt core exhibited an incomplete-cubane-type structure. The decavanadate ring contracts to accommodate a smaller dinuclear unit by taking a wavy conformation and expands to accommodate the larger trinuclear unit. The reverse reaction quantitatively proceeded by the addition of 5 equiv. of [VO3]- with respect to Co3. Although a trinuclear-manganese-core-containing decavanadate [Mn3(H2O)(OAc)V10O30]5- (Mn3) possesses the same structure as that of Co3, the addition of 5 equiv. of [VO3]- yielded a different structure of a dinuclear-manganese-core-containing decavanadate [Mn2V10O30]6- (Mn2) with two cyclic pentavanadate ligands sandwiching the manganese core. Thus, the conformations of the cyclic decavanadates are rearranged to respond to the central metal core structures. EXAFS study suggests both manganese complexes maintain the molecular structure in solution. The simultaneous analyses of the magnetic susceptibility data and the magnetization data revealed the switch of magnetic interaction modes from ferromagnetic in dinuclear complexes to mixed ferromagnetic and antiferromagnetic interactions in trinuclear complexes: the ferromagnetic interaction in dinuclear units of Co2 (J = 8.05 cm-1) and Mn2 (J = 0.76 cm-1) (Hex = -JS1S2), and the ferromagnetic and antiferromagnetic interactions in Co3 (J = -1.59 cm-1 and J′ = 13.6 cm-1) and Mn3 (J = -2.20 cm-1 and J′ = 0.07 cm-1) (Hex = -JSA1SA2 - J′[SA1SB + SA2SB]) were studied. © 2017 The Royal Society of Chemistry.
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| 2.
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2. Formation of vv lacunary polyoxovanadates and interconversion reactions of dodecavanadate species
Okaya, Kenji ; Kobayashi, Tetsuhiro ; Koyama, Yuki ; Hayashi, Yoshihito ; Isobe, Kiyoshi
概要:
金沢大学理工研究域物質化学系<br />Oxidation, reactions of the reduced decavanadate [VIV2Vv8O26]4- (1) with halide guest anions were in
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vestigated for the synthesis of Vv host molecules. The reaction with Cl- afforded a new dodecavanadate, [HVV12O32(C1)]4-(3), which incorporated the guest chloride anion. The polyoxovanadate framework of 3 is different from, the bowl-shaped dodecavanadate [VV12O 32(CH3CN)]4- (2). The structure of 3 is regarded as a trilacunary counterpart of the pentadecavanadate [V V9VIV8O36C1] 4-. Employment: of an F-template yielded the layered polyoxovanadate [HVV11O29F2] 4- (4). The framework of 4 is a monolacunary structure of the fluoride-incorporated dodecavanadate [H6VV2VIv10O30F2] 6-, in which one of the VO groups at the belt position is removed. The three vana-dium atoms in the capping units are connected, by (μ3-F bridges. Reaction with Br provided [HVv12O32(Br)]4- (5) with minor formation of [H3VV10O28]3- Interconversion reactions between 2, 3, and 4 proceeded as follows: the reaction of 2 with Cl- prompted, an isomerization reaction of the bowl-type framework, affording 3; the reaction of 3 with F- gave 4; the reaction of 4 with CH3CN reproduced acetonitrile-incorporated 2. Complexes 3 and 4 were characterized by X-ray analysis. Polyoxovanadates 3 and 4, with the highest oxidation cores, exhibited distinct signals in the 51V NMR spectra, corresponding to lacunary polyoxovanadate geometries. © Wiley-VCH Verlag GmbH & Co. KGaA.
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| 3.
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Hayashi, Yoshihito
概要:
Many synthetic methods for heteropolyoxovanadates and lacunary polyoxovanadates have been developed in recent years. We
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outline various approaches used to produce new polyoxovanadate species, including heterometal-incorporated complexes of tetravanadates, hexavanadates, decavanadates and dodecavanadates. In particular, three types of synthetic routes are explored; based on (i) coordination of metavanadate species to transition metal cations, (ii) oxidation of reduced polyoxovanadates, and (iii) template synthesis. Metavanadate species can coordinate to metal cations as inorganic macrocyclic ligands to form heteropolyoxovanadates. The incorporation of a heterometal cation into decavanadates has also been reported. The oxidation reaction of reduced polyoxovanadates provides a new route to the formation of the lacunary polyoxovanadates, which can serve as inorganic host molecules. Dodecavanadates are bowl-type molecules of particular structural interest; a chloride anion can be incorporated into the bowl through a template synthesis. Structural transformations between these dodecavanadate species and alkoxopolyoxovanadates are also described. © 2011 Elsevier B.V.
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| 4.
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Kayatani, Takayuki ; Hayashi, Yoshihito ; Suzuki, Masatatsu ; Inomata, Katsuhiko ; Uehara, Akira
概要:
A dicopper(II) complex with a novel unsymmetric dinucleating ligand, H2L-1, which can provide donor atom, coordination n
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umber, and geometric asymmetries at metal centers, [Cu2(L-1)(CH3COO)]ClO4·H2O·0.5NaClO4 (1), was synthesized, where H2L-1 is a racemic 1-bis(2-pyridylmethyl)amino-3-salicylideneaminopropan-2-ol. The ligand is a hybrid one of 1,3-bis[bis(2-pyridylmethyl)amino]propan-2-ol (Htpdp) and 1,3-bis(salicylideneamino)propan-2-ol (H3L-2). Crystal structure of 1 was determined by X-ray crystallography. Complex 1 crystallizes in monoclinic space group C2/c with a = 42.704(8), b = 12.689(6), c = 29.008(9) Å, β = 128.28(1)°, and Z = 16. The crystal structure showed that two stereoisomers (1a and 1b) are present in solid state. This is attributable to the presence of an enantiomeric pair of L-1. Dinuclear cations consist of one square-planar site with a NO3 donor set and one five-coordinate site with a N3O2 donor set, which are linked by an endogenous alkoxide bridge of L-1 and an exogenous acetate bridge. A powdered sample of 1 shows weak antiferromagnetic interaction (2.60 B.M./Cu2 at 300 and 1.81 B.M./Cu2 at 5 K). Cryomagnetic data is analyzed using two exchange coupling constants, J1 = −0.18 cm−1 and J2 = −9.05 cm−1. EHMO calculations revealed that the observed weak antiferromagnetic interaction(s) compared with that found for [Cu2(L-2)(CH3COO)] (3) (J = −85 cm−1) is reasonably interpreted in terms of the energy gap and the nature of HOMO and LUMO. Some other physicochemical properties of the complex are discussed in comparison with those of the parent complexes, [Cu2(tpdp)(CH3COO)]2+ (2) and [Cu2(L-2)(CH3COO)] (3).
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| 5.
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Kobayashi, Tetsuhiro ; Kuwajima, Sho ; Kurata, Taisei ; Hayashi, Yoshihito
概要:
A spherical tetradecavanadate, [V14O38(Cl)] 7-, was synthesized from a chloride-incorporated bowl-type dodecavanadate. © 2014 Elsevier B.V. All rights reserved.
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| 6.
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Kikukawa, Yuji ; Yokoyama, Taiga ; Kashio, Sanae ; Hayashi, Yoshihito
概要:
The speciation studies of oxovanadates are essential to clarify their biological activities. We surveyed the distributio
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n of oxovanadate species in the presence of halide anions with various acid concentrations in an aqueous mixed-solvent system. The presence of chloride, bromide, and iodide anions has no effects on the appearance of polyoxovanadate species observed in 51V NMR. Those are the precedent formation of metavanadate species and decavanadates. The presence of fluoride anion during the addition of acids exhibits strong intervention in the polyoxovanadate equilibria and we found the subsequent formation of two polyoxovanadate species by 51V NMR observation. From the estimated experimental condition, we isolated fluoride-incorporated polyoxovanadates {Et<inf>4</inf>N}<inf>4</inf>[V<inf>7</inf>O<inf>19</inf>F] and {Et<inf>4</inf>N}<inf>4</inf>[HV<inf>11</inf>O<inf>29</inf>F<inf>2</inf>], successfully. Polyanion [V<inf>7</inf>O<inf>19</inf>F]4 - is the fluoride-incorporated all V(V) state polyoxovanadate which has two different coordination environments of tetrahedral and square pyramidal vanadium units within the one anionic structural integrity. The structural gap between tetrahedral-unit-based metavanadate and octahedral-unit-based decavanadate structures may be linked by this hybrid complex. © 2015 Elsevier Inc. All rights reserved.<br />Embargo Period 24 months
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| 7.
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Tong, Thu Minh Thi ; Soeta, Takahiro ; Suga, Takuya ; Kawamoto, Keisuke ; Hayashi, Yoshihito ; Ukaji, Yutaka
概要:
An enantioselective formal total synthesis of (+)-manzacidin C is described. A key feature of the synthesis is the const
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ruction of two chiral centers via the asymmetric 1,3-dipolar cycloaddition of an azomethine imine to methallyl alcohol by the use of (S,S)-DIPT as a chiral auxiliary. © 2017 American Chemical Society.<br />Embargo Period 12 months
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| 8.
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Inoue, Yoshitaka ; Kikukawa, Yuji ; Kuwajima, Sho ; Hayashi, Yoshihito
概要:
Chloride-incorporated dodecavanadates show two distinct structures of the monoprotonated-form [HV12O32(Cl)]4- (closed-V1
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2) with a spherical closed-structure and the opened-form [V12O32(Cl)]5- (opened-V12). The reaction of closed-V12 with a stoichiometric amount of ethylenediamine drives the structure transformation reaction to opened-V12, quantitatively. From time dependent observations of 51V NMR, a tube-type intermediate [V12O32(Cl)]5- (tube-V12) was observed in the transformation process. Isolation of the intermediate was achieved by the deprotonation reaction of closed-V12 with diethylamine, and the structure transformation was confirmed by using the isolated intermediate. The reverse transformation from opened-V12 to closed-V12 was also achieved by addition of trifluoroacetic acid. The geometrical difference between closed-V12 and opened-V12 is reflected in the reactivity difference to the external reagents, and this was demonstrated by examining the chloride removal reaction by using a silver cation. The incorporated chloride was preserved in the closed-V12 cage even in the presence of a silver cation. In contrast, the chloride in opened-V12 was removed as AgCl by the silver cation. In addition, by the reaction of chloride-free opened-V12 with a quantitative amount of {Et4N}Cl retrieved opened-V12, showing the capability of opened-V12 to recapture a guest chloride in the cavity. This transformation between two isomeric dodecavanadate structures is regarded as the movement of a molecular mitt to catch a ball and secure it. © 2016 The Royal Society of Chemistry.<br />Embargo Period 12 months
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| 9.
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Inami, Shinnosuke ; Nishio, Masaki ; Hayashi, Yoshihito ; Isobe, Kiyoshi ; Kameda, Hiroyuki ; Shimoda, Tatsuya
概要:
金沢大学理工研究域物質化学系<br />An all-inorganic complex, [Mn2{(CVO3) 5}2]6- (1), was synthesized, and the structure determination r
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eveals a dinuclear manganese complex coordinated by two cyclic pentavanadate ligands. The cyclic pentavanadate units sandwich the edge-sharing octahedral dimanganese core through, coordination of the oxido group of the pentavanadate. A. dinuclear cobalt complex with, a cyclic decavanadate, [Co 2(OH2)2(VO3)10]6- (2), was also synthesized. The structure analysis reveals a dinuclear cobalt complex with a macrocyclic decavanadate, which is composed of 10 VO4 units joined by the vertex. Sharings. The CoO6 octahedrons are edge-shared, with each cobalt octahedron coordinated to five oxido groups from the decavanadate. The remaining site is occupied by - water. The coordinated water molecules are supported with hydrogen bonds in two directions. Complex 2 in acetonitrile shows no reactivity with dioxygen even at low temperature, and the cyclic voltammogram of 2 shows no redox chemistry in acetonitrile. Complex 2 exhibits chromism by water exposure both, in the solid state and. in acetonitrile. Complex 2 is green-yellow in color, and. the addition of water causes the complex to turn brown. After heating the sample, it returns to its original color in a reversible manner. The EXAFS data in acetonitrile is also reported, and is consistent with the solid-state structure. © Wiley-VCH Verlag GmbH & Co. KGaA.
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| 10.
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Domae, Kyosuke ; Uchimura, Daisuke ; Koyama, Yuuki ; Inami, Shinnosuke ; Hayashi, Yoshihito ; Isobe, Kiyoshi ; Kameda, Hiroyuki ; Shimoda, Tatsuya
概要:
金沢大学理工研究域物質化学系<br />A new route to an alkoxohexavanadate species leads to the isolation of a bowl-type dodecavanadate wi
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thout a guest molecule in the cavity. The 1D tetravanadate, [V4O11]2-, is a good precursor for the alkoxohexavanadate, [V6O13(OCH3)6]2-, which is then utilized for the [V6 + V6] coupling reaction to form the dodecavanadate, [V12O42]4-, with a capped dichloromethane molecule at the cavity entrance. We also obtained structural information on a newly discovered octadecavanadate, [V18O46(NO3)]5-, in both the solid and solution states through extended X-ray absorption fine structure (EXAFS) studies. The existence of the chiral inorganic species in acetonitrile with double-stranded V8 chains was confirmed through EXAFS oscillations. © 2009 IUPAC.
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| 11.
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林, 宜仁 ; Hayashi, Yoshihito
概要:
ポリリン酸のようにバナジウムの{VO4}四面体が環状構造を形成した無機大環状配位子をランタニドイオンに配位させた無機錯体の化学を開拓した。異なる環員数を持つ配位子や環状無機配位子のねじれ角の調整によってランタニドイオンの幅広いイオン半径に対
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応し６～８配位構造の錯体を得た。また，単結晶構造解析を行った粉末サンプルおよび溶液サンプルに対しランタニド原子を吸収端とするEXAFS構造解析を行った。FEFFによる多重反射を含めた解析を行い，溶液内での構造保持を確認するとともに詳細な結合距離を明らかにした。<br />The chemistry of all-inorganic coordination complexes of lanthanide ions have been developed by using an inorganic macrocyclic ligand of VO4-based-polyoxovanadates. The syntheses of macrocyclic polyoxovanadate ligands and those lanthanide complexes are conducted except a radioactive element. The coordination complexes with 6 to 8 coordination spheres were isolated with a different ring size and a different coordination environment. EXAFS analyses revealed the retention of the structure in acetonitrile solution and the FEFF analysis with interpretation of multiple scattering revealed the detailed information about the structure in solution.<br />研究課題/領域番号:23550069, 研究期間(年度):2011-2013
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| 12.
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林, 宜仁 ; Hayashi, Yoshihito
概要:
超伝導,磁性,半導体,触媒能など現代文明を支えるハイテク化合物の多くに酸化物が用いられている。最高の性質を求めると酸化物にたどり着き,その分子レベルでの理解が重要となる。しかし,酸化物を分子として合成することは意外にも難しく,前人未踏の世界
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が広がっている。本研究において,酸化物イオンが金属イオンに配位した完全無機錯体の化学を発見し,錯体化学を無機物質にまで拡張できることを証明した。ルイス酸であるさまざまな金属イオンを,バナジウムオキソ酸からポリ酸といわれるオリゴマー酸化物分子を形成し,ヘテロ原子としての遷移金属を取り込んだ酸化物分子を合成した。(Bu_4N)[VO_3]溶液にさまざまな金属塩を加えると,そのルイス酸性によりバナジン酸の縮合反応が進行し,クラウンエーテルと似た環状酸化物[VO_3]_n^<n->イオンが生成する。Co(II),Ni(II),Cu(II),Zn(II)イオンを無水条件で反応させることで,さまざまな環員数nの大環状無機錯体[M_1(VO_3)_n]^<m-> を合成した。これは,環状ポリオキソバナデートが,クラウンエーテルのように金属に配位した無機配位子による配位化学である。また,環状無機錯体から,金属を取り除くとディスク状の酸化物骨格が残され,テンプレート存在下に縮合反応を行わせると,環状酸化物を入り口にしたお椀型のクラスターから球状のクラスターへと骨格変換される。硝酸イオンをテンプレートに用いると,驚くべきことにDNA二重らせんに類似した,バナジウムV8リボンの二重鎖からなる無機不斉分子への発見につながった。戦略的な基礎化合物である酸化物にヘテロ原子として種々の遷移元素を取り込んだ「分子」を,錯体合成できることを立証し,初めて無機二重らせん分子を発見した。本研究により,無機配位子を実際に有効に機能させ興味深い酸化物分子を多数開拓できたので,今後は機能性物質への展開が望まれる。<br />Metal oxide is one of a popular material in high-tech world in modern society such as superconductivities, magnetic or semiconductor properties, and catalysts. When we look for the best properties of all, many of these materials are turning up to be metal oxides, and need to understand those properties from the molecular level. The synthesis of metal oxide as a molecule is seemingly easy, but is a challenge for a chemist for a long time, and unexplored world is wailing. In this study, we discover the chemistry of inorganic complex in which the oxide anion is coordinated to the metal atoms, and we proved the coordination chemistry can be expanded to the world of pure inorganic oxide chemistry. The inorganic complex was achieved by the combination of polyoxovanadates and the metal cations as Lewis acid The Lewis acidity of the metal sources prompt the condensation reaction of the metavanadate species, which is tri or tetramer in acetonitrile solution. The resulting pureinorganic complex of an, Ni(II), Cu(II), and Zn(II) have been synthesized in non-aqueous solution and various oxide molecule with crown-type oxide anion ligands were synthesized. Most of the interesting finding in this study is a discovery of the chiral inorganic molecule. When we condense the vanadate under the presence of nitrate template, we found the formation of two octadecavanadate chains through the nitrate template capped the both ends of the chain by V05 pyramidal units. In other view, the first double helical inorganic molecule had been emerged.The new chemistry of fundamental oxide of vanadium is strategic importance, and the understanding of the variety of properties in oxide can be tackled from the point of molecular chemistry. This study explorer the chemistry of oxide molecule and many interesting formation of disk, cage, chiral oxide molecule have been realized, and further studies will provide the extention toward the functional materials.<br />研究課題/領域番号:16550051, 研究期間(年度):2004-2007<br />出典：「テンプレート反応を利用した半球状バナジウム酸化物分子の構築反応」研究成果報告書 課題番号16550051 (KAKEN：科学研究費助成事業データベース（国立情報学研究所）) 本文データは著者版報告書より作成
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