Researchers Database


    Faculty Division of Natural Sciences Research Group of Chemistry Associate Professor
Last Updated :2021/06/02



  • Engineering, Waseda University

Research Interests

  • 超分子化学 錯体化学 有機金属化学 Supramolecular Chemistry Coordination Chemistry Organometallic Chemistry 

Research Areas

  • Nanotechnology/Materials, Inorganic and coordination chemistry

Research Experience

  • 2008, -:奈良女子大学理学部化学科准教授
  • 2004 - 2007, :早稲田大学理工学術院応用化学科助手
  • 2002 - 2004, :エアランゲンニュルンベルグ大学博士研究員
  • 2001 - 2002, :理化学研究所協力研究員
  • 2001 - 2002, :Contract Researcher
  • 1998 - 2001, :理化学研究所基礎科学特別研究員
  • 1998 - 2001, :Special Postdoctal Researcher
  • 1995 - 1998, :日本学術振興会特別研究員DC1

Published Papers

  • Tetranuclear zigzag Ag4 and Ag2Pt2 complexes supported by rac-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2 (rac-dpmppm)

    Tomoaki Tanase; Risa Otaki; Kanako Nakamae; Yasuyuki Ura; Takayuki Nakajima

    Elsevier BV, Oct. 2020, Journal of Organometallic Chemistry, 925, 121488 - 121488, doi

    Scientific journal

  • Multinuclear Copper Hydride Complexes Supported by Polyphosphine Ligands

    Takayuki Nakajima; Kanako Nakamae; Yasuyuki Ura; Tomoaki Tanase

    Wiley, 23 Jun. 2020, European Journal of Inorganic Chemistry, 2020 (23), 2211 - 2226, doi;url

    Scientific journal

  • Transition Metal Clusters Constrained by Linear Tetradentate Phosphine Ligands

    Takayuki Nakajima; Tomoaki Tanase

    The Chemical Society of Japan, 05 Apr. 2020, Chemistry Letters, 49 (4), 386 - 394, doi;url

    Scientific journal

  • Facially Dispersed Polyhydride Cu 9 and Cu 16 Clusters Comprising Apex‐Truncated Supertetrahedral and Square‐Face‐Capped Cuboctahedral Copper Frameworks

    Kanako Nakamae; Takayuki Nakajima; Yasuyuki Ura; Yasutaka Kitagawa; Tomoaki Tanase

    Wiley, 03 Feb. 2020, Angewandte Chemie International Edition, 59 (6), 2262 - 2267, doi;url;url;url

    Scientific journal

  • Dinuclear Copper Complexes Triply Bridged by a Tetraphosphine, rac-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2

    T. Tanase; R. Otaki; A. Okue; K. Nakamae; T. Nakajima

    Aug. 2019, Eur. J. Inorg. Chem., doi

    Scientific journal

  • Tetra-, hexa-and octanuclear copper hydride complexes supported by tridentate phosphine ligands

    T. Nakajima; K. Nakamae; R. Hatano; K. Imai; M. Harada; Y. Ura; T. Tanase

    Jul. 2019, Dalton Trans, 48, 12050 - 12059, doi

    Scientific journal

  • Synergistic Cu2 Catalysts for Formic Acid Dehydrogenation

    T. Nakajima; Y. Kamiryo; M. Kishimoto; K. Imai; K. Nakamae; Y. Ura; T. Tanase

    May 2019, J. Am. Chem. Soc., 141, 8732 - 8736, doi

    Scientific journal

  • Alloyed Tetranuclear Metal Chains of Pd4-nPtn (n = 0-3) Scaffolded by a New Linear Tetraphosphine Containing a PNP Bridge

    T. Tanase; M. Tanaka; M. Hamada; Y. Morita; K. Nakamae; Y. Ura; T. Nakajima

    Apr. 2019, Chem. Eur. J., 25, 8219 - 8224, doi

    Scientific journal

  • Synthesis and characterization of iridium hydride complexes with meso-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2 (meso-dpmppm) as an unsymmetric pincer ligand

    T. Tanase; N. Mori; K. Nakamae; T. Nakajima

    Mar. 2019, J. Organomet. Chem., 888, 54 - 64, doi

    Scientific journal

  • A decanuclear Pt complex comprised of an unbridged Pt4 chain capped by two Pt3 A-frame units supported by meso-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2

    T. Tanase; M. Urabe; H. Takenaka; K. Nakamae; T. Nakajima

    Jan. 2019, J. Organomet. Chem., 883, 41 - 46, doi

    Scientific journal

  • Tri- and Tetranuclear Copper Hydride Complexes Supported by Tetradentate Phosphine Ligands

    T. Nakajima; Y. Kamiryo; K. Hachiken; K. Nakamae; Y. Ura; T. Tanase

    Sep. 2018, Inorg. Chem., 57, 11005 - 11018, doi

    Scientific journal

  • N-Acyclic carbene complexes supported by meso-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2 (meso-dpmppm) as an asymmetric pincer ligand

    T. Tanase; M. Urabe; N. Mori; S. Hatada; S. Noda; H. Takenaka; K. Nakamae; T. Nakajima

    Aug. 2018, J. Organomet. Chem., 878, 45 - 59, doi

    Scientific journal

  • Synthesis and Reactivity of Thiolate-Bridged (NiMI)-M-II Heterodinuclear Complexes (M = Rh, Ir) with an S-Bidentate NiP2S2 Metalloligand

    Bunsho Kure; Mikie Sano; Natsuki Watanabe; Takayuki Nakajima; Tomoaki Tanase

    The mononuclear complex [Ni(meppp)] {H(2)meppp = meso-1,3-bis[(2-mercaptoethyl)(phenyl)phosphino]propane} was used as an S-bidentate NiP2S2 metalloligand to prepare a series of (NiMI)-M-II complexes with various neutral ligands, namely, [Ni(mu-meppp)ML2]PF6 [M = Rh, L = 1/2cod (1a; cod = 1,5-cycloocatadiene), CO (1b), XylNC (1c; Xyl = 2,6-dimethylphenyl), P(OPh)(3) (1d); M = Ir, L = 1/2cod (2a), CO (2b), XylNC (2c)]. The reactivities of 1 and 2 toward methyl iodide and tertiary hydrosilanes were examined. Complexes 1c, 2a, and 2b reacted with MeI to afford the oxidative addition products [Ni(mu-meppp)M(L)(2)(Me)(I)]PF6 [M = Rh, L = XylNC (3c); M = Ir, L = 1/2cod (4a)] and [Ni(mu-meppp)Ir(CO)(Me)(I)(2)] (5). In the reactions with hydrosilanes, only 2c exhibited an interesting reactivity to afford the Ni-II(mu-H)Ir-III silyl complexes [Ni(mu-meppp)(mu-H)Ir(XylNC)(2)(Si)]PF6 [Si = SiEt3 (6a), SiMe2Ph (6b), SiMePh2 (6c), SiPh3 (6d)]. The reaction proceeded via the intermediate isomers [Ni(meppp)(mu-H)Ir(XylNC)(2)(Si)]PF6 (7); intermediate 7d (Si = SiPh3) was characterized and has an Ni-II(mu-H)Ir-III silyl structure with the hydrido ligand nesting in the reverse side of the Ni(mu-S)(2)Ir pocket to that of 6d. These results demonstrated that the reactivities of the bis(thiolate)-bridged (NiMI)-M-II heterodinuclear complexes can be tuned by changing the metal ions and ancillary ligands. In addition, the S-bidentate NiP2S2 metalloligand [Ni(meppp)] plays an important role in the stabilization of the bridging hydrido ligand in both pockets of the Ni-II(mu-H)Ir-III core owing to the flexibility of the hinged Ni(mu-SR)(2)Ir structure., WILEY-V C H VERLAG GMBH, Sep. 2017, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (35), 4097 - 4109, doi;web_of_science

    Scientific journal

  • A Fluxional Cu8H6 Cluster Supported by Bis(diphenylphosphino)methane and its Facile Reaction with CO2

    Kanako Nakamae; Miho Tanaka; Bunsho Kure; Takayuki Nakajima; Yasuyuki Ura; Tomoaki Tanase

    A copper hydride cluster [Cu-8(m-H)(6)(mu-dppm) (5)](PF6)(2) (dppm= bis(diphenylphosphino) methane) was prepared from reaction of [CuH(PPh3)](6) with dppm in the presence of [Cu(CH3CN)(4)] PF6 and exhibited fluxional behaviors in solution where the hydrides and the phosphines are scrambling around the trans-bicapped octahedral Cu-8 framework. The Cu8H6 complex showed facile reactivity with CO2 (1 atm, RT) to afford a tricopper complex, [Cu-3(m-H)(m-O2CH)(m-dppm)(3)] PF6, which could be developed to unprecedented hydrosilylation of CO2 catalyzed by multinuclear CuH species under mild conditions., WILEY-V C H VERLAG GMBH, Jul. 2017, CHEMISTRY-A EUROPEAN JOURNAL, 23 (40), 9457 - 9461, doi;web_of_science

    Scientific journal

  • Linear Triplatinum Tetrahydride Complex Supported by Triphosphine Ligands, [Pt-3(mu-H)(2)(H)(2)(mu-dpmp)(2)](BF4)(2) {dpmp = bis(diphenylphosphinomethyl)phenylphosphine}

    Tomoaki Tanase; Kana Yamamoto; Rika Hatano; Kanako Nakamae; Bunsho Kure; Yasuyuki Ura; Takayuki Nakajima

    By treating [Pt6(mu-H)(H)(2)(mu-dpmp)(4)]BH4 [4, dpmp = bis(diphenylphosphinomethyl) phenylphosphine] with an excess amount of HBF4 in N, N-dimethylformamide (DMF), a triplatinum tetrahydride complex, [Pt-3(mu-H)(2)(H)(2)(mu-dpmp)(2)](BF4)(2) (5), was obtained in 51 % yield and was characterized by IR, UV/Vis, H-1 NMR, and P-31{H-1} NMR spectroscopy in addition to ESI mass spectrometry, X-ray crystallography, and DFT calculations. Complex 5 is composed of linear trinuclear platinum centers supported by two dpmp ligands, {Pt-3(mu-dpmp) 2}(6+), which accommodate two terminal and two bridging hydrides in a HPtHPtHPtH zigzag structure. The hydride positions were deter-mined by DFT optimization with B3LYP/GD3BJ functionals. Variable- temperature H-1{P-31} NMR spectroscopy in [D7]DMF revealed that the bridging hydrides exhibit fluxional behavior and migrate along the Pt3 chain by switching the bridging site, whereas the terminal hydrides are not exchanged with the bridging ones. The present results suggest that the divalent linear triplatinum unit of {Pt-3(mu-dpmp)(2)}(2+) (Pt-3(II)), which is a building block to construct [Pt-6(mu-H)(H)(2)(mu-dpmp)(4)](+) (4, Pt-3(II)-Pt-3(II)), formally acts as a four-electron source to result in [Pt-3(mu-H)(2)(H)(2)(mu-dpmp)(2)](2+) (5, Pt-3(VI)) through protonation., WILEY-V C H VERLAG GMBH, Mar. 2017, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (11), 1422 - 1426, doi;web_of_science

    Scientific journal

  • Chiral Self-Recognition between Stereogenic Tetrapalladium Units Affording Pd-8 Chains Supported by Homochiral Tetraphosphines

    Tomoaki Tanase; Konomi Morita; Risa Otaki; Kana Yamamoto; Yukino Kaneko; Kanako Nakamae; Bunsho Kure; Takayuki Nakajima

    By using a chiral tetraphosphine, rac-bis[(diphenylphosphinomethyl)phenylphosphino]methane (rac-dpmppm), linear octapalladium chains were synthesized as discrete molecules of [Pd-8(mu-rac-dpmppm)(4)L-2](BF4)(4) (L=CH3CN, dmf, XylNC), [Pd-8(mu-rac-dpmppm)(4)](BF4)(4), and [Pd-8(mu-rac-dpmppm)(4)(Cl)(2)](BF4)(2), which are stable in the solution states and characterized by spectroscopic and crystallographic methods to reveal the octapalladium chains supported by homochiral four tetraphosphines. Variable-temperature NMR studies for a 1:1 mixture of [Pd-8(mu-rac-dpmppm)(4)(dmf)(2)](BF4)(4) and [Pd-8(mu-meso-dpmppm)(4)(dmf)(2)](BF4)(4) in [D-7]DMF revealed that the Pd-8 chains were dissociated at higher temperature (T approximate to 140 degrees C) into the Pd-4 units of {Pd-4(mu-rac-dpmppm)(2)}(2+) and {Pd-4(mu-meso-dpmppm) 2}(2+), and they were thermodynamically self-aligned to restore the Pd-8 chains at lower temperature (T < 60 degrees C), through perfect chiral self-recognition between the stereogenic tetrapalladium units., WILEY-V C H VERLAG GMBH, Jan. 2017, CHEMISTRY-A EUROPEAN JOURNAL, 23 (3), 524 - 528, doi;web_of_science

    Scientific journal

  • Homo- and Heterodinuclear Rh and Ir Complexes Supported by SNn Mixed -Donor Ligands (n=2-4): Stereochemistry and Coordination -Site -Exchange Reactions of Cp*M (M Rh, Ir) Units

    Takayuki Nakajima; Yuki Kawasaki; Bunsho Kure; Tomoaki Tanase

    A series of SNn mixed-donor ligands [n = 2: H2NC2H4SCH2-2-pyridyl (2-NSpY) (1a), H2NC2H4SCH2-4-pyridyl (4-NSpy) (1b), n = 3: 2-pyridylCH(2)NHC(2)H(4)SCH(2)-2-pyridyl (2-pyNSpy) (2), n = 4: (2-pyridylCH(2))(2)NC2H4SCH2-2-pyridyl (2-py2NSPY) (3)] was utilized to support homo- and heterodinuclear complexes including Cp*MIII units (M = Rh, Ir; Cp* = pentamethylcyclopentadienyl). Reactions of [Cp*MCI2](2) with 2-pyNSpy (2), 2-py(2)NSpy (3), and 4-NSpy (1b) afforded homodinulear complexes, [(Cp*MC1)(2-pyNSpy)(Cp*MCI)(1)(PF6)(2) [M = Rh (5a), Ir (5b)], [(Cp*M)(2-py2NSpy)(Cp*MCW(PF6)3 [M = Rh (6a), Ir (6b)], [(Cp*MCI)(4-NSpy)(Cp*MC12)1C1 [M = Rh (8a), Ir (8b)L Heterodinuclear complexes [(Cp*MCI)(4-NSpy)(Cp*M,Cl-2)[Cl [M, M' = Rh, Ir (8c), Ir, Rh (8d)] were prepared using mononuclear complexes [(Cp*MC1)(4-NSpy)1C1 [I\A = Rh (7a), Ir (7b)] reacted with [Cp*MCI2](2) (M = Ir, Rh), respectively. Complexes 5-8 were characterized by X-ray crystallography to determine the configurations around the M, M', 5, and N centers. The solid-state structures of 6 are retained in acetonitrile solution whereas four diastereomers are generated in the case of 5 due to low stereo selectivity around the coordinated amine nitrogen atom, in contrast to the sulfur atom. Heterodinuclear complexes 8c,d are unstable in solution at 55 degrees C, readily affording mixtures of 8a-d via intra- and intermolecular coordination-site-exchange reactions of Cp*M fragments between the SN moiety and the py site. In order to evaluate the selectivity of Cp*M fragments for the SN and py coordination sites, several competitive reactions of [Cp*MCl2](2) (M = Rh, Ir) with H2NC2H4SCH2C6H5 (NSph) (4) and/or 4-methylpyridine (4-Mepy) were carried out to demonstrate predominant formation of iridium complexes 9b and 10b among [(Cp*MCl)(NSph)]Cl EM = Rh (9a), Ir (9b)] and [(Cp*MCl)(4-Mepy)Kl [M = Rh (10a), Ir (10b)]. These reactions indicated higher affinity of the COI- fragment to both the NS and py sites relative to the rhodium analogue., WILEY-V C H VERLAG GMBH, Oct. 2016, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (28), 4701 - 4710, doi;web_of_science

    Scientific journal

  • Synthesis and structure of trihydride hexaplatinum complex supported by triphosphine ligands, [Pt-6(mu-H)(H)(2)(mu-dpmp)(4)]BH4 (dpmp = bis(diphenylphosphino-methyl)phenylphosphine)

    Tomoaki Tanase; Kana Yamamoto; Kanako Nakamae; Bunsho Kure; Takayuki Nakajima

    From a reaction of [Pt-3(mu-dpmp)(2)(XylNC)(2)](PF6)(2) (1a) with NaBH4 and [Pt(dba)(2)] in N,N-dimethyl formamide (DMF), a trihydride hexaplatinum complex, [Pt-6(mu-H)(H)(2)(mu-dpmp)(4)]BH4 center dot DMF (4*center dot DMF), was isolated as dark green crystals in 47% yield, and was characterized by IR, UVevis, H-1 and P-31{H-1} NMR, and ESI mass spectral analyses, X-ray crystallography, and DFT calculations. Complex 4* is stable in DMF and DMSO solutions, and contains two terminal and one bridging hydrides observed at -5.92 ppm ((1)J(PtH) = 980 Hz) and -4.47 ppm ((1)J(PtH) = 591 Hz) in the H-1 NMR spectrum(DMSO-d(6)). The X-ray diffraction analysis revealed the linear hexaplatinum structure supported by four dpmp ligands, wherein two {Pt-3(H)(m-dpmp)(2)}(+) units are connected by the bridging hydride resulting in a long Pt/Pt separation (3.3075(6) angstrom) between the central two Pt atoms. Other Pt-Pt distances range from 2.7243(7) to 2.7499(6) angstrom, indicating the presence of PtePt bonds within the {Pt-3(mu-dpmp)(2)} units. On the basis of the crystal structure, the hydride positions were optimized by DFT calculations to show a bent bridging hydride (av. Pt-H = 1.65 angstrom, Pt-H-Pt = 160.0 degrees) as well as linear terminal ones (av. Pt-H = 1.68 angstrom, av. Pt-Pt-H = 179.4 degrees). The present study provides useful information in expanding molecular metallic chains by utilizing {H-Pt-3-H-Pt-3-H}(+) building blocks. (C) 2016 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA, Jul. 2016, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 814, 35 - 41, doi;web_of_science

    Scientific journal

  • Systematic Synthesis of Di-, Tri-, and Tetranuclear Homo- and Heterometal Complexes Using a Mononuclear Copper Synthon with a Tetradentate Amino Alcohol Ligand

    Takayuki Nakajima; Chisako Yamashiro; Megumi Taya; Bunsho Kure; Tomoaki Tanase

    The reaction of Cu(NO3)(2)center dot 3H(2)O with an N2O2 tetradentate amino alcohol, N,N-dibenzyl-N',N'-bis(2-hydroxyethyl)ethylenediamine (H2L), afforded the mononuclear copper complex [Cu(H2L)(NO3)](NO3) (1), which has been used to construct a series of di-, tri-, and tetranuclear homo-and heterometallic complexes. Complex 1 dimerized in the presence of NEt3 to form the Cu-2 complex [Cu-2(HL)(2)](NO3)(2) (2) by the deprotonation of one of the two hydroxy groups in the H2L ligand. The reaction of 1 with Cu(OCOH)(2) in the presence of NEt3 afforded the Cu-3 complex [Cu-3(HL)(2)(OCOH)(2)](NO3)(2) (5). The metalloligand {Cu(HL)}(+) derived from 1 reacted with M(OAc)(2) (M = Cu, Co, Zn, Ni) in the absence of NEt3 to form the asymmetric CuM dinuclear complexes [CuM(HL)(OAc)(NO3)(2)] [M = Cu (3a), Co (3b), Zn (3c), Ni (3d)], whereas in the presence of NEt3 a unit of M(OAc) was captured by two metalloligands to give the bent CuMCu trinuclear complexes [Cu2M(HL)(2)(OAc)(2)(NO3)](NO3) [M = Cu (4a), Co (4b), Mn (4c)], which were further transformed into the linear CuMCu trinuclear complexes [Cu-3(HL)(2){(PhO)(2)PO2}(2)](NO3)(2) (7a) and [Cu2M(HL)(2){(PhO)(2)PO2}(2)(MeOH)(2)](NO3)(2) [M = Co (7b), Mn (7c)] with the aid of diphenyl phosphate bridging ligands. When (PhO) PO2(OH) was used as an auxiliary bridging ligand in the reaction of 1 with M(OAc)(2) and NEt3, the Cu2M2 tetranuclear complexes [Cu2M2(HL)(2){(PhO) PO3}(2)(NO3)(2)] [M = Co (8a), Zn (8b)] were synthesized. These results demonstrate that the mononuclear copper synthon with the N2O2 tetradentate amino alcohol ligand {Cu(H2L)}(2+) generates the quite useful metalloligand {Cu(HL)}(+) by the deprotonation of a hydroxy group, and subsequent reactions lead to the construction of a series of homo-and heterometal complexes containing Cu-2, CuM (M = Cu, Co, Zn, Ni), bent-CuMCu (M = Cu, Co, Mn), linear-CuMCu (M = Cu, Co, Mn), and Cu2M2 (M = Co, Mn) cores in a systematic and selective manner., WILEY-V C H VERLAG GMBH, Jun. 2016, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (17), 2764 - 2773, doi;web_of_science

    Scientific journal

  • Oxidative addition of an aromatic ortho C-H bond of tetraphosphine to asymmetric diiridium(I) centres

    Takayuki Nakajima; Sayo Noda; Miyuki Sakamoto; Aya Matsui; Kanako Nakamae; Bunsho Kure; Yasuyuki Ura; Tomoaki Tanase

    Reactions of a tetraphosphine, meso-bis{[(diphenylphosphinomethyl) phenyl] phosphino} propane (dpmppp), with [IrCl(cod)](2) and CO (1 atm) or isocyanide (RNC) in the presence of NH4PF6 at 80-100 degrees C in dichloromethane/acetonitrile/acetone and/or methanol mixed solvents afforded asymmetric diiridium(II) complexes, [Ir-2(H)(Cl)(mu-(dpmppp-H)-kappa(PC)-C-4)(CO)(3)]PF6 (1) and [Ir-2(H)(mu-(dpmppp-H)-kappa(PC)-C-4)(RNC)(4))]-(PF6)(2) (R = 2,6-xylyl (2), 2,4,6-mesityl (3); dpmppp-H = {PPh(o-C6H4)CH2P(Ph)(CH2)(3)P(Ph) CH2PPh2}(-)). A similar reaction with (BuNC)-Bu-t resulted in the formation of a mononuclear Ir-III complex of [Ir(H)(dpmppp-kappa P-3)((BuNC)-Bu-t)(2)](PF6)(2) (4). Complexes 1-3 were characterized by ESI mass spectrometry, H-1 and P-31 NMR spectroscopy and X-ray diffraction analyses. They were found to consist of cis/trans-P, P asymmetric (IrII-IrII) bonded dinuclear structures derived from oxidative addition of an ortho C-H bond of dpmppp (Ir-Ir = 2.8044(2) angstrom (1), 2.8569(2) angstrom (2), and 2.8524(5) angstrom (3)), resulting in a [IrPCCIr] intermetallic cyclometal-bridge and a terminal hydride. DFT calculations indicated the presence of Ir-Ir, Ir-H, and Ir-C-ortho covalent bonds. Initial stages of the reactions with CO and XylNC at room temperature were investigated by P-31{H-1} NMR spectroscopy and found to contain a symmetrical Ir-I dinuclear unit with dpmppp that was readily transformed into 1 and 2 upon heating. The Ir-2(I) intermediate with XylNC, [Ir-2(XylNC)(4)(mu-dpmppp)] (PF6)(2) (6), was isolated and characterized by X-ray crystallography and DFT calculations as an electron-deficient 32e(-)Ir(2)(I) species involving a IrI. IrI dative bond (2.7989(5) angstrom). The reaction pathways from 6 to 2 were investigated by DFT calculations. The present study suggested that a novel oxidative addition of an ortho C-H bond proceeded on the cis/trans-P, P asymmetric diiridium(I) scaffold supported by the tetraphosphine, dpmppp, which was assumed to be facilitated by dimetal cooperation with switching Ir -> Ir dative interactions., ROYAL SOC CHEMISTRY, 2016, DALTON TRANSACTIONS, 45 (11), 4747 - 4761, doi;web_of_science

    Scientific journal

  • Electron-rich linear triplatinum complexes stabilized by a spinning tetraphosphine, tris(diphenylphosphinomethyl)phosphine

    Tomoaki Tanase; Kanako Koike; Miho Uegaki; Satoko Hatada; Kanako Nakamae; Bunsho Kure; Yasuyuki Ura; Takayuki Nakajima

    Linear triplatinum complexes with 48e(-), [Pt3(mu-tdpmp)(2)(RNC)(2)](PF6)(2) (R = 2,6-xylyl (3), Bu-t (4)), were synthesized by using a branched tetraphosphine, tris(diphenylphosphinomethyl) phosphine (tdpmp), and characterized by crystallographic and spectroscopic analyses to show their novel dynamic behaviour in the solution state, in which the linear Pt3 unit was stabilized by two spinning tetraphosphine ligands., ROYAL SOC CHEMISTRY, 2016, DALTON TRANSACTIONS, 45 (17), 7209 - 7214, doi;web_of_science

    Scientific journal

  • Gold and Silver Chains Supported by Linear Hexaphosphine Ligands

    Tomoaki Tanase; Mio Chikanishi; Konomi Morita; Kanako Nakamae; Bunsho Kure; Takayuki Nakajima

    A new linear hexaphosphine, rac-cis,cis,trans-bis{[(diphenylphosphinomethyl)phenylphosphinomethyl]-phenylphosphino}methane (P-6), was synthesized and isolated as a pure isomer, confirmed by transforming to the corresponding phosphine sulfide. The methylene-bridged linear hexaphosphine readily organized flexible gold(I) and silver(I) hexanuclear chains, [M-6(mu-P-6)(2)]X-6 (X-6=(OTf)(6), M=Au (1), Ag (2); X-6=Cl-2(PF6)(4), M=Au (3)). The hexaphosphine also supported a tetrasilver(I) complex [Ag-4(mu-P-6)(2)](OTf)(4) (4), which was readily transformed by treatment with AgOTf into 3, revealing a drastic alternation of the two P-6 arrangement. The hexagold(I) chains exhibited a considerably red-shifted absorption (similar to 410 nm) and emission (540-580 nm) to (1)[5d(sigma*)-> 6p(sigma)] and from (3)[5d(sigma*)-> 6p(sigma)] excited states of the metal centers, respectively. The new linear hexaphosphine could be a useful tool to construct linear metal clusters as subnano building blocks., WILEY-V C H VERLAG GMBH, Dec. 2015, CHEMISTRY-AN ASIAN JOURNAL, 10 (12), 2618 - 2622, doi;web_of_science

    Scientific journal

  • Synthesis and structures of dinuclear Rh-III and Ir-III complexes supported by a tetraphosphine, meso- or rac-bis {[(diphenylphosphinomethyl)phenyl]phosphino]}methane

    Tomoaki Tanase; Akiko Yoshii; Risa Otaki; Kanako Nakamae; Yumina Mikita; Bunsho Kure; Takayuki Nakajima

    Reactions of [Cp*MCl2](2) with meso-or rac-dpmppm in the presence of NH4PF6 afforded mixtures of stereoisomers formulated as [(Cp*MCl)(2)(meso- or rac-dpmppm)](PF6)(2), from which the major isomers, rac-M-2-[(Cp*MCl)(2)(meso-dpmppm)](PF6)(2) (M = Rh (1a), Ir (1b)) and rac-M-2-[(Cp*MCl)(2)(rac-dpmppm)](PF6)(2) (M = Rh (2a), Ir (2b)), were isolated and characterized by IR, UV-vis, ESI mass, and H-1 and P-31{H-1} NMR spectroscopy and X-ray crystallography, where dpmppm is bis{[(diphenylphosphino-methyl) phenyl] phosphino}methane and Cp* is eta(5)-pentamethylcyclopentadienyl. The isomeric tetra-phosphine incorporates two {Cp*MCl} fragments with four-membered chelation through a pair of outer and inner phosphine units, and fixes them ca. 6.9 angstrom apart from each other. The configurations around the metal centers in 2 were determined to avoid repulsive interaction between the phenyl group on the inner P atom and the M-bound chloride anion, while those in 1 would be determined by minimizing not only the Ph/Cl repulsion but also repulsion between the two metal fragments. In the dichloromethane solutions, the major isomers 1 and 2 were not converted to any other minor isomers even at high temperature, but in dmf and dmso, only 1a was readily transformed into the minor isomer, meso-M-2-[(Cp*RhCl)(2)(meso-dpmppm)](PF6)(2). Cyclic voltammograms of 1a, b and 2a, b demonstrated two irreversible 2e reduction waves corresponding to (MMIII)-M-III -> (MMIII)-M-I -> (MMI)-M-I, in which the mixed-valence states with meso-dpmppm could be stabilized to a larger extent than with rac-dpmppm. Complex 1a heated in acetonitrile with AgOTf/NH4OTf afforded a Rh2Ag2 mixed-metal complex, [(Cp*Rh(CH3CN))(2)Ag-2(OTf)(2)(meso-dpmppm)(2)](OTf)(4) (5). (C) 2015 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA, Nov. 2015, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 797, 37 - 45, doi;web_of_science

    Scientific journal

  • Stepwise Expansion of Pd Chains from Binuclear Palladium(I) Complexes Supported by Tetraphosphine Ligands

    Tomoaki Tanase; Satoko Hatada; Sayo Noda; Hiroe Takenaka; Kanako Nakamae; Bunsho Kure; Takayuki Nakajima

    Reaction of [Pd-2(XyINC)(6)]X-2 (X = PF6, BF4) with a linear tetraphosphine, meso-bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm), afforded binuclear Pd-I complexes, [Pd-2(mu-dpmppm)(2)]X-2 ([2]X-2), through an asymmetric dipallachum complex, [Pd-2(mu-dpmppm)(XylNC)(3)](2+) ([1](2+)). Complex [2](2+) readily reacted with [Pd-0(dba)(2)] (2 equiv) and an excess of isocyanide, RNC (R = 2,6-xylyl (Xyl), tert-butyl (Bu-t), to generate an equilibrium mixture of [Pd-4(mu-dpmppm),(RNC)(2)](2+) ([3'](2+)) + RNC reversible arrow [Pd-4(mu-dpmppm)(2) (RNC)(3)](2+) ([3](2+)), from which [Pd-4(mu-dpmppm)2(XylNC)(3)](2+) ([3a](2+)) and [Pd-4(mu-dpmppm)(2) ((BUNC)-B-t)(2)](2+) ([3b'](2+)) were isolated. Variable-temperature UV-vis and P-31{H-1} and H-1 NMR spectroscopic studies on the equilibrium mixtures demonstrated that the tetrapalladium complexes are quite fluxional in the solution state: the symmetric Pd-4 complex [3b'](2+) predominantly existed at higher temperatures (>0 degrees C), and the equilibrium shifted to the asymmetric Pd-4 complex [3b'](2+) at a low temperature (similar to-30 degrees C). The binding constants were determined by UV-vis titration at 20 degrees C and revealed that XylNC is of higher affinity to the Pd-4 core than (BuNC)-Bu-t. In addition, both isocyanides exhibited higher affinity to the electron deficient [Pd-4(mu-dpmppmF(2))(2)(RNC)(2)](2+) ([3F'](2+)) than to [Pd-4(mu-dpmppm)(2)(RNC)(2)](2+) ([3'](2+)) (dpmppmF(2) = meso-bisadi(3,5-difluorophenyl)phosphinomethyl}phenylphosphino]methane). When [2] X-2 was treated with [Pd-0(dba)(2)] (2 equiv) in the absence of RNC in acetonitrile, linearly ordered octapalladium chains, [Pd-8(mu-dpmppm)(4)(CH3CN)(2)]X-4 ([4]X-4: X = PF6, BF4), were generated through a coupling of two {Pd-4(mu-dpmppm)(2)}(2+) fragments. Complex [2](2+) was also proven to be a good precursor for Pd2M2 mixed-metal complexes, yielding [Pd2Cl(Cp*MCl) (Cp*MCl2)(mu-dpmppm)(2)](2+) (M = Rh ([5](2+)), Ir ([6](2+)), and [Au2Pd2Cl2(dpmppm-H)(2)](2+) ([7])(2+) by treatment with [Cp*MCl2](2) and [AuCl(PPh3)], respectively. Complex [7]2+ contains an unprecedented PC(sp(3))P pincer ligand with a PCPCPCP backbone, dpmppm H of deprotonated dpmppm. The present results demonstrated that the binuclear Pd-I complex [2](2+) was a quite useful starting material to extend the palladium chains and to construct Pd-involved heteromultinuclear systems., AMER CHEMICAL SOC, Sep. 2015, INORGANIC CHEMISTRY, 54 (17), 8298 - 8309, doi;web_of_science

    Scientific journal

  • Synthesis, Magnetic Properties, and X-ray Spectroscopy of Divalent Cobalt(II) and Nickel(II) Cubanes [M-4(II)(HL2)(4)(OAc)(4)]

    Andreas Scheurer; Jana Korzekwa; Takayuki Nakajima; Frank Hampel; Anna Buling; Christine Derks; Manfred Neumann; Loic Joly; Konstantin Petukhov; Klaus Gieb; Paul Mueller; Karsten Kuepper; Karsten Meyer

    Under anaerobic conditions, the reactions of cobalt(II) and nickel(II) acetate tetrahydrate with 2,6-pyridinedimethanol (H2L2, 3) in anhydrous acetonitrile afforded two tetranuclear metal(II) complexes [M-4(II)(HL2)(4)(OAc)(4)] (4; M-II = Co2+, Ni2+) with a [M-4(mu(3)-O)(4)](4+) cubane core. X-ray structural analyses revealed that both MII cubanes 4a center dot 2CH(3)OH and 4b center dot 2CH(3)OH are isostructural and crystallize in the tetragonal space group I4(1)/acd with eight molecules in the unit cell. In the solid state, the orientation of the cubane cores of 4 and the formation of a 3D framework were controlled by pi-pi interactions as well as intra- and intermolecular O-H center dot center dot center dot O hydrogen bonds. Variable-temperature magnetic susceptibility measurements revealed that the cubanes 4 show a ferrimagnetic coupling scheme that leads to a diamagnetic ground state for both complexes. Core-level X-ray photoelectron spectroscopy confirmed that the Co and Ni ions in 4a and 4b are in a divalent state. X-ray magnetic circular dichroism was performed to extract the spin and orbital contributions to the Co and Ni magnetic moments. We compared the experimental results of the local electronic structures around the Co2+ ions in 4a and the Ni2+ ions in 4b with charge-transfer multiplet simulations., WILEY-V C H VERLAG GMBH, Apr. 2015, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (11), 1892 - 1901, doi;web_of_science

    Scientific journal

  • Self-Alignment of Low-Valent Octanuclear Palladium Atoms

    Kanako Nakamae; Yukie Takemura; Bunsho Kure; Takayuki Nakajima; Yasutaka Kitagawa; Tomoaki Tanase

    A linear tetraphosphine, meso-bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm) was used to synthesize linear octapalladium-extended metal atom chains as discrete molecules of [Pd-8(mu-dpmppm)(4)](BF4)(4) (1) and [Pd-8(mu-dpmppm)(4)L-2](BF4)(4) (L = 2,6-xylyl isocyanide (XylNC; 2), acetonitrile (3), and N, N-dimethylformamide (dmf; 4)), which are stable in the solution states and show interesting temperature-dependent photochemical properties in the near IR region. Variable temperature NMR studies demonstrated that at higher temperature T approximate to 140 degrees C the Pd-8 chains were dissociated into Pd-4 fragments, which were thermodynamically self-aligned to restore the Pd-8 chains at lower temperature T < 60 degrees C. The coldspray ionization mass spectra suggested a possibility for further aggregation of the linear tetrapalladium units., WILEY-V C H VERLAG GMBH, Jan. 2015, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 54 (3), 1016 - 1021, doi;web_of_science

    Scientific journal

  • Facile Insertion of Carbon Dioxide into Cu-2(mu-H) Dinuclear Units Supported by Tetraphosphine Ligands

    Kanako Nakamae; Bunsho Kure; Takayuki Nakajima; Yasuyuki Ura; Tomoaki Tanase

    Reactions of meso-bis[(diphenylphosphinomethyl) phenylphosphino] methane (dpmppm) with Cu-I species in the presence of NaBH4 afforded di- and tetranuclear copper hydride complexes, [Cu-2(mu-H)(mu-dpmppm)(2)]X (1) and [Cu-4(mu-H)(2)(mu(4)-H)(mu-dpmppm)(2)]X (2) (X = BF4, PF6). Complex 1 undergoes facile insertion of CO2 (1 atm) at room temperature, leading to a formate-bridged dicopper complex [Cu-2(mu-HCOO)(dpmppm)(2)]X (3). The experimental and DFT theoretical studies clearly demonstrate that CO2 insertion into the Cu-2(mu-H) unit occurred with the flexible dicopper platform. Complex 2 also undergoes CO2 insertion to give a formate-bridged complex, [Cu-4(mu-HCOO)(3)(dpmppm)(2)]X, during which the square Cu-4 framework opened up to a linear tetranuclear chain., WILEY-V C H VERLAG GMBH, Nov. 2014, CHEMISTRY-AN ASIAN JOURNAL, 9 (11), 3106 - 3110, doi;web_of_science

    Scientific journal

  • Synthesis and structures of Pd2M2 (M = Cu, Au) and Pd2M (M = Cu, Ag) mixed-metal complexes supported by NPPN tetradentate ligands

    Takayuki Nakajima; Minori Tsuji; Naoko Hamada; Yuki Fukushima; Bunsho Kure; Tomoaki Tanase

    Reactions of [PdCl(Me)(cod)] with two NPPN mixed-donor tetradentate ligands, meso-2-pyridylCH(2)(Ph) P(CH2)(2)P(Ph)CH2-2-pyridyl (meso-picppe) and rac-2-pyridylCH(2)(Ph)P(CH2)(4)P(Ph)CH2-2-pyridyl (rac-picppb), afforded dinuclear palladium complexes [(PdCl(Me))(2)(meso-picppe)] (1) and [(PdCl(Me))(2)(rac-picppb)] (2), which were further converted with 2,6-xylyl isocyanide (XylNC) to [(PdCl(C(=NXyl) Me))(2)(meso-picppe)] (3) and {(PdCl(C(=NXyl)Me))(2)(rac-picppb)] (4) through insertion of XylNC into the Pd-Me bonds. Complexes 3 and 4 possess two imidoyl moieties which are of potential donors and readily capture d(10) group 11 metal ions depending on their stereostructures of the NPPN ligands. Reactions of 3 with CuCl or AuCl(tht) afforded Pd2M2 mixed-metal tetranuclear complexes [(PdCl(C(=NXyl) Me)(MCl))(2)(meso-picppe)] (M = Cu (5a), Au (5b)), where each imidoyl moiety captures a MCI fragment in a C-i symmetrical fashion. Similar reactions of 4 with [Cu(MeCN)(4)]BF4 or AgBF4 resulted in Pd2M trinuclear complexes [(PdCl(C(=NXyl)Me)(2)M(rac-picppb)]BF4 (M = Cu (6a), Ag (6b)), in which two imino groups chelate a M-I ion with a pseudo C-2 symmetrical structure. (C) 2014 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA, Oct. 2014, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 768, 61 - 67, doi;web_of_science

    Scientific journal

  • Tetranuclear Nickel and Cobalt Complexes with an Incomplete Double-Cubane Structure-Homo- and Heterometallic Complexes and Their 1D Coordination Polymers

    Takayuki Nakajima; Keiko Seto; Andreas Scheurer; Bunsho Kure; Takashi Kajiwara; Tomoaki Tanase; Masahiro Mikuriya; Hiroshi Sakiyama

    The reactions of M(OAc)(2 center dot)4H(2)O (M = Ni, Co) with three unsymmetrical amine-did l ligands RN(CH2CH2OH)-(CH2CH2CH2OH) (H2Ln: n =1 , R = benzyl, n = 2, R = 4-methylenzyl]; n = 3, R = 2-naphthalenylmethyl) in the presence of NEt3 or pyridine in MeOH or BnOH gave the tetranuclear complexes [M-4(HLn)(2)(OAc)(6)(MeOH)(2)] {M = Ni, n = 1 (la), 2 (lb), 3 (1c) M = Co, n = 1 (4a), 2 (4b), 3 (4c)} and [M-4(HLn)(2)-(OAc)(6)(BnOH)(2)] {M = Ni, n = 1 (2a), 2 (2b), 3 (2c); M = Co, n = 1 (5a), 2 (5b), 3 (5c)}. When p-xylene-alpha,alpha'-diol was used instead of monoalcohols, the tetranuclear (M4O6) units were linked by p-xylene-alpha,alpha'-diol to form the 1D coordination polymers [M-4(HLn)(2)(OAc)(6)(p-HOH2C6H4CH2OH)](m) {M = Ni, n = 1 (3a), 2 (3b); M = Co, n = 1 (6a), 2 (6b)). The structures of 1-6 were determined by X-ray crystallography and consist of centrosymmetrical tetranuclear (M4O6)) face-shared defective double-cubane cores supported by two monodeprotonated (HLn-) ligands. The mixed-metal letranuclear complexes [Ni2.2Co1.8(HL1)(2)(OAc)(6)(MeOH)(2)] (7) and [Mn1.7Ni2.3(HL1)(2)(OAc)(5)(OMe)(2)] (8) were also synthesized by using e.quimolar amounts of Ni2+ and M2+ (M = Co, Mn) ions. X-ray crystallographic and :fluorescent analyses.revealed that 7 is isomorphous with 1a and 4a and contains.nonstoichiometric amounts of disordered Ni2+ and Co2+ ions in an average ratio of 2.2:1.8 with different occupancies for the two crystallographically independent metal centers. In contrast, 8 consists of a C-2-symmetrical face-shared defective doublecubane ((M3MnO6)-Mn-II-O-III) core with a Ni/Mn ratio of 2.3:1.7, the amounts of Ni2+ and Mn2+ ions vary depending on the metal sites, and one of the C-2 axial positions is exclusively occupied by Nin ions. Detailed magnetostru.ctural analyses on the nickel (1a, 2a, 3a) mid cobalt (4a) complexes with appropriate spin-Hamiltoulau. models showed that both iferro- and antiferromagnetic spin exchange interactions were involved within the tetranuclear units, and their extent depends on the combination of the metal ions and -the ligand systems in a delicate fashion., WILEY-V C H VERLAG GMBH, Oct. 2014, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (29), 5021 - 5033, doi;web_of_science

    Scientific journal

  • Systematic Heterodinuclear Complexes with MM '(mu-meppp) Centers That Tune the Properties of a Nesting Hydride (M = Ni, Pd, Pt; M ' = Rh, Ir; H(2)meppp = meso-1,3-Bis[(mercaptoethyl)phenylphosphino]propane)

    Bunsho Kure; Mikie Sano; Takayuki Nakajima; Tomoaki Tanase

    Mononuclear complexes with a P2S2 ligand, [M(meppp) (M = Ni (1a), Pd (1b), Pt (1c); H(2)meppp = meso-1,3-bis[(mercaptoethyl)phenylphosphino]propane), were treated with [M'Cp*Cl-2](2) or [M'Cp*(NO3)(2)] (Cp* = eta(5)-pentamethylcyclopentadienyl) to afford a series of bisthiolate-bridged (MM)-M-II'(III) heterodinuclear complexes, [M(mu-meppp)-M'Cp*X]X' (M = Ni, Pd, Pt; M' = Rh, It; X = Cl, NO3; X' = Cl, PF6, NO3). The nitrate complexes [M(mu-meppp)-M'Cp*(NO3)]NO3 (M' = Rh ([4a-c]NO3), Ir ([5a-c]NO3); M = Ni (a), Pd (b), Pt (c)) further reacted with sodium formate in water or methanol to be transformed into bisthiolate- and hydride-bridged complexes, [M(mu-meppp)(mu-H)M'Cp*]NO3 (M' = Rh ([6a-c]NO3), Ir ([8a-c]NO3); M = Ni (a), Pd (b), Pt (c)). Complexes [6a]NO3 (M = Ni, M' = Rh) and [8a]NO3 (M = Ni, M' = Ir) were characterized by X-ray analyses to reveal that a hydride is stabilized in a semibridging mode on the heterometal centers. In the (PdRhIII)-Rh-II ([6b]NO3) and (PtRhIII)-Rh-II ([6c]NO3) complexes, the hydrides were extremely unstable and were likely to undergo an unusual metal-to-Cp* ring hydrogen transfer, resulting in eta(4)-C5Me5H (MRhI)-Rh-II complexes, [M(mu-meppp)Rh(eta(4)-C5Me5H)]NO3 (M = Pd ([7b]NO3), Pt ([7c]NO3)). The property of the hydride was drastically switched by varying the anchoring metal ions of the M' site (Rh, Ir); that of [6a]NO3 (M' = Rh) is not protic and decomposes in water below pH 4, while those of [8a-c]NO3 (M' = Ir) are protic, subject to H+/D+ exchange reactions, and stable below pH 4. [6a]NO3 reacted with phenylacetylene to give [Ni(mu-meppp)RhCp*(C CPh)]NO3 ([10a]NO3), which is in contrast with the inertness of the (NiIrIII)-Ir-II hydride complex [8a]NO3. The reaction is assumed to involve an alkenyl complex, [Ni(mu-meppp)RhCp*(CH=CHPh)]NO3 (9a), formed through an insertion of phenylacetylene into the metal-hydride bond. Analogous (MRhIII)-Rh-II alkynyl complexes, [M(mu-meppp)RhCp*(C CPh)]NO3 (M = Pd ([10b]NO3), Pt ([10c]NO3)), were synthesized by treating [4b,c]NO3 with phenylacetylene in basic media, and the structural differences among [10a-c]NO3 were discussed. These results interestingly demonstrated that the structures, properties, and reactivities of the nesting hydride on the {MM'(mu-meppp)} cores were tuned by varying metal ions of the M and M' sites., AMER CHEMICAL SOC, Aug. 2014, ORGANOMETALLICS, 33 (15), 3950 - 3965, doi;web_of_science

    Scientific journal

  • One-dimensional Anisotropic Metal-Organic Module Containing a Pt-6 Chain Terminated with Redox Active Ferrocenyl Units

    Tomoaki Tanase; Chie Yamamoto; Bunsho Kure; Takayuki Nakajima

    A 1D anisotropic hexaplatinum chain with redox-active terminal ligands, [Pt-6(mu-H)(mu-dpmp)(4)(FcDipNC)(2)](PF6)(3) (7) (dpmp: bis(diphenylphosphinomethyl)phenylphosphine, FcDipNC: 2,6-dlisopropyl-4-(ferrocenylethynylene)phenyl isocyanide), was synthesized, its structure and electrochemical behavior were elucidated in comparison with those of [Pt-6(mu-H)(mu-dpmp)(4)(DipNC)(2)](PF6)(3) (6) (DipNC: 2,6-diisopropylphenyl isocyanide), and the module was found to undergo two stepwise two-electron oxidations., CHEMICAL SOC JAPAN, Jun. 2014, CHEMISTRY LETTERS, 43 (6), 913 - 915, doi;web_of_science

    Scientific journal

  • Electron-Deficient Pt2M2Pt2 Hexanuclear Metal Strings (M = Pt, Pd) Supported by Triphosphine Ligands

    Eri Goto; Rowshan Ara Begum; Chiaki Ueno; Aya Hosokawa; Chie Yamamoto; Kanako Nakamae; Bunsho Kure; Takayuki Nakajima; Takashi Kajiwara; Tomoaki Tanase

    Electron-deficient Pt2M2Pt2 hexanuclear clusters, [Pt4M2(mu-dpmp)(4)(XylNC)(2)](PF6)(4) (M = Pt (7), Pd (8); dpmp = bis((diphenylphosphino)methyl)phenylphosphine), were synthesized by oxidation of hydride-bridged hexanuclear clusters [Pt4M2(mu-H)(mu-dpmp)(4)(XylNC)(2)](PF6)(3) (M = Pt (2), Pd (3)) and were revealed to involve a linearly ordered Pt2M2Pt2 array joined by delocalized bonding interactions with 84 cluster valence electrons, which are discussed on the basis of DFT calculations. The central MM distances of 7 and 8 are significantly reduced upon the apparent loss of a hydride unit from the MHM central part of 2 and 3, indicating that the bonding electrons in the adjacent MPt bonds migrate into the central MM bond to result in a dynamic structural change during two-electron oxidation of the hexanuclear metal strings. A similar Pt-6 complex terminated by two iodide anions, [Pt6I2(mu-dpmp)(4)](PF6)(2) (9), was synthesized from [Pt-6(mu-H)I-2(mu-dpmp)(4)](PF6) (5) by treatment with [Cp2Fe][PF6]. Complexes 7 and 8 were readily reacted with the neutral two-electron donors XylNC, CO, and phosphines to afford the trinuclear complexes [Pt2M(mu-dpmp)(2)(XylNC)L](PF6)(2) (M = Pt, L = XylNC (la), CO (10), PPh3 (11); M = Pd, L = XylNC (1b)) through cleavage of the electron-deficient central M-M bond. 'When complex 7 was reacted with the diphosphines (PP) trans-Ph2PCH=CHPPh2 (dppen) and Ph2P(CH2)(2)PPh2 (dppe), the diphosphine was inserted into the central M-M bond to afford [(XylNC)Pt-3(mu-dpmp)(2)(PP)Pt-3(mu-dpmp)(2)(XylNC)](PF6)(4) (12), which was transformed by treatment with another 1 equiv of diphosphine into the asymmetric trinuclear complexes [Pt-3(mu-dpmp)(2)(XylNC)(PP)](PF6)(2) (13). A further ligand exchange reaction of 13a (PP = trans-dppen) provided the diphosphine-terminated symmetrical Pt3 complex [Pt-3(mu-dpmp)(2)(L)(2)](PF6)(2) (L = trans-dppen (14a)). Complexes 7 and 8 were also reacted with [AuCl(PPh3)] to yield the Pt2MAu heterotetranuclear complexes [Pt2MAuCl(mu-dpmp)(2)(PPh3)(XylNC)RPF6)(2) (M = Pt (15), Pd (16)), in which the Pt2M trinuclear fragment is inserted into the Au-Cl bond in a 1,1-fashion on the central M atoms of the Pt2M2Pt2 string., AMER CHEMICAL SOC, Apr. 2014, ORGANOMETALLICS, 33 (8), 1893 - 1904, doi;web_of_science

    Scientific journal

  • Strongly Luminous Tetranuclear Gold(I) Complexes Supported by Tetraphosphine Ligands, meso- or rac-Bis[(diphenylphosphinomethyl)phenylphosphino]methane

    Tomoaki Tanase; Risa Otaki; Tomoko Nishida; Hiroe Takenaka; Yukie Takemura; Bunsho Kure; Takayuki Nakajima; Yasutaka Kitagawa; Taro Tsubomura

    A series of tetragold(I) complexes supported by tetraphosphine ligands, meso- and rac-bis[(diphenylphosphinomethyl)phenylphosphino] methane (meso- and rac-dpmppm) were synthesized and characterized to show that the tetranuclear Au-I alignment varies depending on syn- and anti-arrangements of the two dpmppm ligands with respect to the metal chain. The structures of syn-[Au-4(meso-dpmppm)(2)X]X-3' (X=Cl; X'=Cl (4a), PF6 (4b), BF4 (4c)) and syn-[Au-4(meso-dpmppm)(2)]X-4 (X=PF6 (4d), BF4 (4e), TfO (4 f); TfO=triflate) involved a bent tetragold(I) core with a counter anion X incorporated into the bent pocket. Complexes anti-[Au-4(meso-dpmppm)(2)]X-4 (X=PF6 (5d), BF4 (5e), TfO (5 f)) contain a linearly ordered Au-4 string and complexes syn-[Au-4(rac-dpmppm)(2)X-2]X-2' (X=Cl, X'=Cl (6a), PF6 (6b), BF4 (6c)) and syn-[Au-4(rac-dpmppm)(2)]X-4 (X=PF6 (6d), BF4 (6e), TfO (6 f)) consist of a zigzag tetragold(I) chain supported by the two syn-arranged rac-dpmppm ligands. Complexes 4d-f, 5d-f, and 6d-f with non-coordinative large anions are strongly luminescent in the solid state (lambda(max)=475-515 nm, Phi=0.67-0.85) and in acetonitrile (lambda(max)=491-520 nm, Phi=0.33-0.97); the emission was assigned to phosphorescence from 3[d(sigma*sigma*sigma*)p(sigma sigma sigma)] excited state of the Au-4 centers on the basis of DFT calculations as well as the long lifetime (a few mu s). The emission energy is predominantly determined by the HOMO and LUMO characters of the Au-4 centers, which depend on the bent (4), linear (5), and zigzag (6) alignments. The strong emissions in acetonitrile were quenched by chloride anions through simultaneous dynamic and static quenching processes, in which static binding of chloride ions to the Au-4 excited species should be the most effective. The present study demonstrates that the structures of linear tetranuclear gold(I) chains can be modified by utilizing the stereoisomeric tetraphosphines, meso- and rac-dpmppm, which may lead to fine tuning of the strongly luminescent properties intrinsic to the Au-4(I) cluster centers., WILEY-V C H VERLAG GMBH, Feb. 2014, CHEMISTRY-A EUROPEAN JOURNAL, 20 (6), 1577 - 1596, doi;web_of_science

    Scientific journal

  • Configurational Isomerization of Dinuclear Iridium and Rhodium Complexes with a Series of NPPN Ligands, 2-PyCH2(Ph)P(CH2)nP(Ph)CH2-2-Py (Py = Pyridyl, n=2-4)

    Takayuki Nakajima; Yuki Fukushima; Minori Tsuji; Naoko Hamada; Bunsho Kure; Tomoaki Tanase

    New heterodonor NPPN tetradentate ligands, 2-PyCH2(Ph)P-(CH2)(n) P(Ph)CH2-2-Py (meso- and rac-L-n; n = 2-4, Py = pyridyl), were prepared and reacted with [Cp*MCl2](2) (M = Ir, Rh; Cp* is pentamethylcyclopentadienyl) in the presence of NH4BF4 to afford a series of dinuclear complexes [(Cp*MCl)(2)(meso-L-n)](BF4)(2) (M = Ir, n = 2 (2a), 3 (3a), 4 (4a); M = Rh, n = 2 (2c), 3 (3c), 4 (4c)) and [(Cp*MCl)(2)(rac-L-n)](BF4)(2) (M = Ir, n = 2 (2b), 3 (3b), 4 (4b); M = Rh, n =, 2 (2d), 3 (3d), 4 (4d)), which were characterized by IR, H-1 and (31)p{H-1} NMR, and ESI mass spectroscopic techniques and X-ray crystallography. The configurations around the two metal centers were controlled by the configuration of the coordinated P atoms so as to avoid repulsive interaction between the phenyl group on P and the chloride ligand, resulting in the formation of stereospecific isomers; a mesa configuration of the metal centers is induced from meso-L-n (abbreviated as meso-P-2/meso-M-2), and in contrast, a rac configuration is induced from rac-L" (rac-P-2/rac-M-2). Furthermore, inversion of metal centers for the Ir-2 complexes occurred in DMSO at higher temperatures (60-100 degrees C), generating equilibrium mixtures of minor diastereomers (meso-P-2/rac-M-2 or rac-P-2/meso-M-2) in low ratios together with the major isomers (meso-P-2/meso-M-2 or rac-P-2/rac-M-2). The equilibrium constants, K = [minor isomer]/[major isomer], varied appreciably depending on the lengths of the methylene chains as well as configurations of the NPPN ligands; the overall propensity for the K values was observed to be L-2 < L-3 <L-4 and meso-L-n < rac-L-n, while rac-L-3, rac-L-4, and meso-L-4 showed almost identical equilibrium constants, presumably resulting from no steric influence between the two metal centers., AMER CHEMICAL SOC, Dec. 2013, ORGANOMETALLICS, 32 (24), 7470 - 7477, doi;web_of_science

    Scientific journal

  • Reversible dioxygen binding on asymmetric dinuclear rhodium centres

    T. Nakajima; M. Sakamoto; S. Kurai; B. Kure; T. Tanase

    Apr. 2013, Chem. Commun., 49, 5239 - 5338, doi

    Scientific journal

  • Synthesis and structure of a dinuclear NiIIIrIII hydride complex supported by a N3S2 bridging ligand: Comparison of property and reactivity of dinuclear NiII(H)MIII units (M = Rh, Ir) in aqueous media

    B. Kure; T. Nakajima; T. Tanase

    Mar. 2013, J. Organomet. Chem., 733, 28 - 35, doi

    International conference proceedings

  • Flexible, linear, tetranuclear palladium complexes supported by tetraphosphine ligands with electron-withdrawing groups

    Tomoaki Tanase; Satoko Hatada; Ayaka Mochizuki; Kanako Nakamae; Bunsho Kure; Takayuki Nakajima

    A linearly ordered tetraphosphine containing electron-withdrawing substituent groups on the outer phosphorus atoms, meso-bis[{di(3,5-difluorophenyl)phosphinomethyl}phenylphosphino]methane (dpmppmF(2)), was prepared and reacted with [Pd-2(RNC)(6)](PF6)(2) and Pd(dba)(2) to afford tetranuclear palladium complexes, [Pd-4(mu-dpmppmF(2))(2)(RNC)(3)](PF6)(2) (R = 2,6-xylyl (Xyl) (1), 2,4,6-mesityl (2), 2,6-diisopropylphenyl (3) and tert-butyl (4)), which involve an asymmetric {(RNC)Pd-4(CNR)(2)}(2+) core supported by two dpmppmF(2) ligands in anti-arrangement. Each terminal of the Pd4 chain was capped by terminal isocyanide and a semi-bridging RNC is introduced into one terminal Pd site. Mechanistic investigation suggested that the dipalladium(I) complex, [Pd-2(mu-dpmppmF(2))(2)(RNC)(2)](PF6)(2) (R = Xyl (6)), was a key intermediate to trap Pd-0 species by the uncoordinated outer phosphine pendants with electron-withdrawing groups. Variable-temperature UV-vis and P-31{H-1}, H-1 NMR spectroscopic studies demonstrated that the tetrapalladium complexes are quite fluxional in the solution state at high temperature (>20 degrees C) relating to a symmetric structure of [Pd4(mu-dpmppmF2) 2(RNC) 2](PF6) 2, and the asymmetric solid state structures are retained even in the solution at low temperature (<-60 degrees C). Theoretical calculations with DFT methods on the asymmetric (R = Xyl (1)) and symmetric (R = Xyl (1')) structures suggested that contribution of Pd-0 -> Pd-I-Pd-0-Pd-I with 60 cluster valence electrons (CVEs) would be dominant in 1, while the symmetric structure of 1' can be recognized as Pd-I-Pd-0-Pd-0-Pd-I with 58 CVEs. The new tetraphosphine dpmppmF2 was proven very effective in organizing dynamically flexible tetrapalladium chains., ROYAL SOC CHEMISTRY, 2013, DALTON TRANSACTIONS, 42 (45), 15941 - 15952, doi;web_of_science

    Scientific journal

  • Hydride-Bridged Pt2M2Pt2 Hexanuclear Metal Strings (M = Pt, Pd) Derived from Reductive Coupling of Pt2M Building Blocks Supported by Triphosphine Ligands

    Eri Goto; Rowshan Ara Begum; Aya Hosokawa; Chie Yamamoto; Bunsho Kure; Takayuki Nakajima; Tomoaki Tanase

    Linear Pt2M2Pt2 hexanuclear clusters [Pt4M2(mu-H)(mu-dpmp)(4)(XylNC)(2)](PF6)(3) (M = Pt (2a), Pd (3a); dpmp = bis(diphenylphosphinomethyl)phenylphosphine) were synthesized by site-selective reductive coupling of trinuclear building blocks, [Pt2M(mu-dpmp)(2)(XylNC)(2)](PF6)(2) (M = Pt (1a), Pd (1b)), and were revealed as the first example of low-oxidation-state metal strings bridged by a hydride with M-H-M linear structure. The characteristic intense absorption bands around 583 nm (2a) and 674 nm (3a) were assigned to the HOMO-LUMO transition on the basis of a net three-center/two-electron (3c/2e) bonding interaction within the central M-2(mu-H) part. The terminal ligands of 2a were replaced by H-, I-, and CO to afford [Pt-6(mu-H)(H)(2)(mu-dpmp)(4)](+) (4), [Pt-6(mu-H)I-2(mu-dpmp)(4)](PF6) (5), and [Pt-6(mu-H)(mu-dpmp)(4)(CO)(2)](PF6)(3) (6). The electronic structures of these hexaplatinum cores, {Pt-6(mu-H)(mu-dpmp)(4)}(3+), are varied depending on the sigma-donating ability of axial ligands; the characteristic HOMO-LUMO transition bands interestingly red-shifted in the order of CO < XylNC < I- < H- which was in agreement with calculated HOMO-LUMO gaps derived from DFT optimizations of 2a, 4, 5, and 6. The nature of the axial ligands influences the redox activities of the hexanuclear complexes; 2a, 3a, and 5 were proven to be redox-active by the cyclic voltammograms and underwent two-electron oxidation by potentiostatic electrolysis to afford [Pt4M2(mu-dpmp)(4)(XylNC)(2)](PF6)(4) (M = Pt (7a), Pd (8a)). The present results are important in developing bottom-up synthetic methodology to create nanostructured metal strings by utilizing fine-tunable metallic building blocks., AMER CHEMICAL SOC, Dec. 2012, ORGANOMETALLICS, 31 (24), 8482 - 8497, doi;web_of_science

    Scientific journal

  • Wheel-Shaped Icosanuclear Homo- and Heterometallic Complexes of Ni-II, Co-II, and Cu-II Ions Supported by Unsymmetrical Aminoalcohol Ligands

    Takayuki Nakajima; Keiko Seto; Fumihiro Horikawa; Isao Shimizu; Andreas Scheurer; Bunsho Kure; Takashi Kajiwara; Tomoaki Tanase; Masahiro Mikuriya

    Reactions of M(OAc)(2)center dot 4H(2)O (M = Ni, Co) with 3-[benzyl(2-hydroxyethypamino]-1-propanol (H2L) in the presence of pyridine or triethylamine afforded novel homometallic icosanuclear wheel-shaped complexes [M20L4(HL)(4)(OAc)(28)] (M = Ni (1), Co (2)), which consist of a central M-12(II) single-stranded, nearly planar loop with four peripheral [M-2(HL)(OAc)(2)] fragments attached in an S-4 symmetrical fashion. The complexes can alternatively be recognized as saddle-shaped wheel structures, in which four tetranuclear units of [M4L(HL)(OAc)(2)](2-) are connected by four M2+ ions (M5). The tetranuclear unit itself can be derived from an ideal C-2 symmetrical [M-4(HL)(2)(mu-eta(2)-OAc)(4)(mu-eta(1),eta(1)-OAc)(2)(eta(1),eta(1)-OAc)](-) structure through deprotonation of the HL- ligand, and is composed of two plane shared M3O4 incomplete cubanes in which the M2 and M3 atoms are involved in the central fused plane and the M1 and M4 atoms are disposed at the apex sites. Mixed-metal icosanuclear complexes [NixM20-xL4(HL)(4)(OAc)(28)] (3, M = Co, x = 9.5) and [Ni12M8L4(HL)(4)(OAc)(28)] (4, M = Cu) were also synthesized by using equimolar amounts of Ni-II and ions, and were shown to have similar structures to 1 and 2. X-ray crystallographic and fluorescent analyses revealed that complex 3 contains nonstoichiometric amounts of Ni2+ and Co2+ ions in the ratio of 9.5:10.5 and that these are disordered at every metal site. In striking contrast, complex 4 has a stoichiometric formula of Ni12Cu8, which was confirmed by the Jahn-Teller elongation of Cu2+ ions, and consequently, the M2 and M5 positions are occupied exclusively by the Cu2+ ions. The temperature-dependent direct current (dc) magnetic susceptibility data showed the presence of ferromagnetic exchange interactions in the Ni homometallic (1) and NiCu bimetallic (4) complexes, while the Co homometallic (2) and NiCo bimetallic (3) complexes exhibited antiferromagnetic interactions due to spin-orbit coupling effects of the octahedral Co-II ions. The present results demonstrate that the unsymmetrical aminoalcohol ligand H2L is quite effective in organizing the homo- and heterometallic icosanuclear wheel-shaped metal arrangements., AMER CHEMICAL SOC, Nov. 2012, INORGANIC CHEMISTRY, 51 (22), 12503 - 12510, doi;web_of_science

    Scientific journal

  • Hydride-Bridged NiRh Complexes with Tunable N3S2 Dithiolato Ligands and Their Utilization as Catalysts for Hydrogenation of Aldehydes and CO2 in Aqueous Media

    Bunsho Kure; Ayami Taniguchi; Takayuki Nakajima; Tomoaki Tanase

    New N3S2 dithiolato ligands, 1,4-bis(2-mercaptoethyl)-7-R-1,4,7-triazacyclononane (RTACN-S2H2; R = Ts, Pr-i) were synthesized and reacted with Ni-II ion to give mononuclear complexes [Ni(RTACN-S-2)] (R = Ts (1a), Pr-i (1b)). Complexes 1a and 1b were further transformed by treatment with Rh-III species into a series of (NiRhIII)-Rh-II heterodimetallic compounds, [Ni(RTACN-S-2)RhCp*X]X' (R = Ts, X = Cl, X' = Cl, OTf ([2a]X'); R = Ts, X = X' = NO3 ([3a]NO3); R = Pr-i, X = Cl, X' = Cl, NO3, PF6 ([2b]X')). Complexes [3a]NO3 and [2b]NO3 were readily reacted with H-2 (0.1 MPa) in water at room temperature to afford hydride-bridged (NiRhIII)-Rh-II dinuclear complexes, [(RTACN-S-2)Ni(mu-H)RhCp*]NO3 (R = Ts ([4a]NO3), Pr-i ([4b]NO3)), which were successfully characterized by X-ray crystallography. Upon the heterolytic activation of H-2, the Ni-Rh interatomic distances were dramatically decreased from 3.2130(6)-3.262(2) angstrom ([2a]OTf, [2b]NO3, [3a]NO3) to 2.6921(6)-2.7228(4) angstrom ([4a]NO3, [4b]NO3), resulting in semibridging Ni(mu-H)Rh cores. In addition, the stability of the hydride of [4a](+) and [4b](+) were interestingly tuned by varying the R group of the TACN ligand through trans influence at the Ni-II center (Ni-NR=2.188(3) angstrom ([4a(+)]), 2.056(2) angstrom ([4b](+)). In fact, [4a](+) was quite stable and capable of reducing benzaldehyde in water, although [4b] quickly decomposed under similar conditions. Catalytic hydrogenation of aldehydes and CO2 in water has been established by using [3a]NO3 and [2a]Cl as precursors of an active species, [4a](+), and found to be interestingly contrasted to the inactive precursor [2b]NO3 with R = Pr-i. These results indicated that the properties and reactivity of the Ni(mu-H)Rh complexes can be controlled by changing the substituents of the N3S2 supporting ligands., AMER CHEMICAL SOC, Jul. 2012, ORGANOMETALLICS, 31 (13), 4791 - 4800, doi;web_of_science

    Scientific journal

  • Cyclic Trinuclear Rh2M Complexes (M = Rh, Pt, Pd, Ni) Supported by meso-1,3-Bis[(diphenylphosphinomethyl)phenylphosphino]propane

    Takayuki Nakajima; Sachi Kurai; Sayo Noda; Maki Zouda; Bunsho Kure; Tomoaki Tanase

    Reaction of [MCl2(cod)] (M = Pd, Pt) with a tetraphosphine, meso-1,3-bis[(diphenylphosphinomethyl)phenylphosphino]propane (dpmppp), afforded the mononuclear complexes [MCl2(dpmppp)] (M = Pd (3a), Pt (3b)), in which the dpmppp ligand coordinated to the M ion by two inner phosphorus atoms to form a six-membered chelate ring with two outer phosphines uncoordinated. The pendant outer phosphines readily reacted with [RhCl(CO)(2)](2) to give the cationic heterotrinuclear complexes [MRh2(mu-Cl)(3)(mu-dpmppp) (CO)(2)]X (X = [RhCl(CO)(2)](2), M = Pd (4a), Pt (4b); X = PF6, M = Pd (5a), Pt (5b)). The nickel analogue [NiRh2(mu-Cl)(3)(mu-dpmppp)(CO)(2)]PF6 (5c) was also prepared. A neutral homotrinuclear Rh-3 complex, [Rh-3(mu-Cl)(3)(mu-dpmppp)(CO)(2)] (6), was synthesized by the reaction of [RhCl(CO)(2)](2) with dpmppp and was further reacted with HgX2 (X = Cl, Br, I) to afford the Rh3Hg tetranuclear complexes [Rh-3(HgX)(mu-Cl)(2)(mu-X)(mu-dpmppp)(CO)(2)]PF6 (X = Cl (7a), Br (7b), I (7c)), where the Rh-3(mu-Cl)(2)(mu-X) cores act as tridentate ligands to form three donor-acceptor Rh -> Hg interactions. The two CO ligands of 7a-c were replaced by XylNC to yield [Rh-3(HgX)(mu-Cl)(2)(mu-X)(mu-dpmppp)(XylNC)(2)]PF6 (X = Cl (8a), Br (8b), I (8c)). The isocyanides had an appreciable influence on the three Rh -> Hg interactions, which was monitored by the (2)J(Hgp) values observed in the P-31{H-1} NMR spectra and discussed on the basis of DFT calculations. Complex 6 also reacted with CuCl and HBF4 to give [Rh-3(CuCl)(mu-Cl)(3)(mu-dpmppp)(CO)(2)] (9) and [Rh-3(mu(3)-H)(mu-Cl)(3)(mu-dpmppp)(CO)(2)]BF4 (10), respectively. These results suggested that the new tetraphosphine dpmppm proved quite useful in constructing fine-tunable heterometallic frameworks., AMER CHEMICAL SOC, Jun. 2012, ORGANOMETALLICS, 31 (11), 4283 - 4294, doi;web_of_science

    Scientific journal

  • Heterotrinuclear Complexes with Palladium, Rhodium, and Iridium Ions Assembled by Conformational Switching of a Tetraphosphine Ligand around a Palladium Center

    Akiko Yoshii; Hiroe Takenaka; Hiroko Nagata; Sayo Noda; Kanako Nakamae; Bunsho Kure; Takayuki Nakajima; Tomoaki Tanase

    Reaction of [PdCl2(cod)] with a tetraphosphine, meso-bis[((diphenylphosphino)methyl)phenylphosphino]methane (dpmppm), afforded the mononuclear Pd-II complexes [PdCl(dpmppm-kappa(3))]X (X = Cl (la), PF6 (1b)); the pincer-type dpmppm ligand coordinates to the Pd atom with two outer and one inner phosphorus atom to form fused six- and four-membered chelate rings. The remaining inner phosphine is uncoordinated and readily reacts with [CP*MCl2](2) to give the heterodimetallic complexes [PdCl-(Cp*MCl2)(mu-dpmppm-kappa(3),kappa(1))]X (X = Cl, M = Rh (21a), Ir (21b); X = PF6, M = Rh (23a), Ir (23b)). Attachment of the second metal fragment to the uncoordinated phosphine caused a crucial conformational change of the six-membered chelate ring from a stable chair conformation to a twist-boat structure, which concomitantly destabilizes the four-membered ring for its opening reactions. Complexes 21 (X = Cl) were converted to [PdCl2(Cp*MCl2)(dpmppm=O)], in which the terminal P atom is dissociated and oxidized as Ph2P(=O)CH2P(Ph)CH2P(Ph)CH2PPh2 (dpmppm=O), and in the presence of another 1 equiv of [Cp*M'Cl-2](2), complexes 21 were readily transformed into the heterotrinuclear complexes [PdCl2(Cp*M'Cl-2)(Cp*MCl2)(mu-dpmppm-kappa(2),kappa(1),kappa(1))] (M = M' = Rh (31a), Ir, (31b); M = Ir, M' = Rh (31c)), where the third metal M' is trapped by the terminal P atom with its four-membered-ring opening. Complexes 23 also reacted with another 1 equiv of [Cp*M'Cl-2](2) to afford the heterotrinuclear complexes [PdCl(mu-Cl)(Cp*M'Cl)(Cp*MCl2)(mu-dpmppm-kappa(2),kappa(1),kappa(1))]PF6 (M = M' = Rh (32a), Ir, (32b); M = Ir, M' = Rh (32c), M = Rh, M' = Ir (32d)); the additional metal M' is ligated by the terminal phosphine and is further connected to the Pd atom via a chloride bridge, resulting in a rather electron-deficient M' center on the basis of cyclic voltammetry. These results exhibited that the addition of a bulky metal fragment to the uncoordinated phosphine of 1 brings about a conformational switch around the Pd center to promote the ring-opening reaction of the four-membered chelate ring, which leads to an incorporation of the third metal fragment to construct heterotrinuclear structures., AMER CHEMICAL SOC, Jan. 2012, ORGANOMETALLICS, 31 (1), 133 - 143, doi;web_of_science

    Scientific journal

  • Octanuclear iron(III) complexes supported by Kemp's tricarboxylate ligands

    Yukie Takemura; Yayoi Okui; Bunsho Kure; Takayuki Nakajima; Tomoaki Tanase; Masahiro Mikuriya; Masashi Takahashi

    Reactions of FeCl2 center dot 4H(2)O and diimino ligand (L) with H(3)kta (cis,cis-1,3,5-trimethylcyclohexane-1,3,5-tricarboxylic acid) in the presence of [(Bu4N)-Bu-n][OH] afforded a series of octanuclear iron(III) complexes formulated as [Fe8O5(kta)(2)(Hkta)(4)(L)(2)] (L = bpy (1), 5,5'-Me(2)bpy (2), 4,4'-Me(2)bpy (3), phen (4), 4-Mephen (5), 4,7-Me(2)phen (6), and 3,4,7,8-Me(4)phen (7)). The structure of 4 was determined by X-ray crystallography to consist of a planar {Fe-8(mu(4)-O)(mu(3)-O)(4)}(14+) core supported by two kta(3) tricarboxylates, where the inner four Fe-III ions form a {Fe4O5} square plane, of which apex mu-oxo atoms are further connected to the outer four Fe-III ions. The peripheral part of the Fe-8 core is bridged by four Hkta(2) ligands and chelated by two phen ligands. Fe-57 Mossbauer spectra of 2 at 290 K and 77 K indicated the presence of high-spin octahedral Fe(III) ions, and the temperature dependent dc magnetic susceptibility data for 1, 2, and 4 showed strong antiferromagnetic exchange in the {Fe8O5} moiety. (C) 2011 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA, Dec. 2011, INORGANICA CHIMICA ACTA, 379 (1), 100 - 108, doi;web_of_science

    Scientific journal

  • Intramolecular Metal-Metal Bond Rearrangement in a Pt2PdHg Heterometallic Cluster Forming a Hg-I-Pd-I Covalent Bond

    Aya Hosokawa; Bunsho Kure; Takayuki Nakajima; Kanako Nakamae; Tomoaki Tanase

    Reaction of the linear trinuclear complex [Pt2M(mu-dpmp)(2)(XylNC)(2)](PF6)(2) (M = Pd (1b)) with HgX2 afforded the Pt2PdHg mixed-metal complexes [Pt2PdHgX2(mu-dpmp)(2)(XylNC)(2)](PF6)(2) (X = Cl (2), Br (3), I (4)), which included an unprecedented Hg-I-Pd-I covalent bond formed via intramolecular metal-metal bond rearrangement. In contrast, reaction of 1a (M = Pt) with HgCl2 afforded the novel pentagonal-shaped Pt3Hg3 planar cluster [Pt3Hg3Cl4(mu-dpmp)(2)(XylNC)(2)]Cl-2(PF6)(2) (5)., AMER CHEMICAL SOC, Nov. 2011, ORGANOMETALLICS, 30 (22), 6063 - 6066, doi;web_of_science

    Scientific journal

  • Systematic Expansion of Supercubane Cores in Manganese Oxo Clusters with Tricarboxylate Ligands

    Yayoi Okui; Florina Aurelia Catusanu; Ryoko Kubota; Bunsho Kure; Takayuki Nakajima; Tomoaki Tanase; Takashi Kajiwara; Masahiro Mikuriya; Hitoshi Miyasaka; Masahiro Yamashita

    A novel class of high-nuclearity Mn-17 and Mn-19 mixed-valent complexes, [Mn-17(mu-O)(12)(mu-OMe)(2)(mu-kta)(6)(MeOH)(4)] (1), [Mn-17(mu-O)(14)(mu-kta)(6)L-4] [L = bpy (2a), phen (2b), 4,7-Ph(2)phen (2c), dmf (3)], and [Mn-19(mu-O)(14)(mu-kta)(6)(bpy)(6)]X-3 [X = PF6 (4a), BF4 (4b)], were synthesized by utilizing Kemp's tricarboxylate ligands (H(3)kta = cis,cis-1,3,5-trimethylcyclohexane-1,3,5- tricarboxylic acid). The complexes were characterized by X-ray crystallography and reveal mineralomimetic Mn-13 supercubane units, [Mn-13(mu-O)(14)], in which their oxidation states systematically altered, depending on their vertex face-capping ligands and Mn-II satellite fragments. Complex 2a was converted by treatment with benzoic acid and [Mn2O2(bpy)(4)](BF4)(3) to a cage-type Mn-14 complex, [Mn-14(mu-O)(12)(mu-OH)(6)(mu-Hkta)(6)(bpy)(6)](BF4)(4) (5), which show ferro- and antiferromagnetic interactions and slow magnetic relaxation at low temperature., WILEY-V C H VERLAG GMBH, Oct. 2011, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (28), 4325 - 4330, doi;web_of_science

    Scientific journal

  • Stepwise Construction of Au4Ag2Cu2 Coinage Rings Supported by Linear Tetraphosphine Ligands

    Yukie Takemura; Tomoko Nishida; Bunsho Kure; Takayuki Nakajima; Masayasu Iida; Tomoaki Tanase

    WILEY-V C H VERLAG GMBH, Sep. 2011, CHEMISTRY-A EUROPEAN JOURNAL, 17 (38), 10528 - 10532, doi;web_of_science

    Scientific journal

  • 炭素安定同位体多重標識α-アミノ酸及び5-Aminolevulinic Acid の合成

    末木 俊輔; 上原 悠介; 飯泉 礼子; 小林 祥一朗; 趙 依文; 中島 隆行; 清水 功雄

    2010, 安定同位体と生体ガス医学応用, 2, 29 - 34

    Scientific journal

  • Synthesis and Characterization of Linear Tetranuclear Silver(I) Complexes Bridged by Tetraphosphane Ligands

    Yukie Takemura; Takayuki Nakajima; Tomoaki Tanase

    Reactions of AgOTf with meso-bis[(diphenylphosphanylmethyl)phenylphosphanyl]methane (dpmppm) afforded [Ag(4)(OTf)(2)(m-OTf)(m-dpmppm)(2){(CH(3))(2)CO}](OTf) (1) and [Ag(4)(OTf)(2)(m-OTf)(m-dpmppm)(2)(RNC)(2)](OTf) [R = Xyl (2a), Mes (2b), tBu (2c)}. When AgOTf was treated with dpmppm in air in the presence of tBuNC, cleavage of the C-Cl and P-C bonds occurred to give [Ag(4)(m-Cl)(m-dpmppm)(2)(tBu-NC)(4)](OTf)(3) (3) and [Ag(4)(m-Ph(2)PO(2))(m-dpmppm)(2)(tBuNC)3]-(OTf)(3) (4). Reaction of AgOCOCF(3) with dpmppm resulted in [Ag(4)(OCOCF(3))(2)(m-OCOCF(3))(m-dpmppm)(2)](CF(3)COO) (5). By treatment of AgPF(6) with dpmppm, [Ag(4)(m-dpmppm)(2)-(tBuNC)(4)](PF(6))(4) (6) and [Ag(4)(PO(2)F(2))(2)(m-dpmppm)(2)(tBuNC)(2)] (PF(6))(2) (7) were obtained. Wheareas complexes 1-3 possess a [Ag(4)(m-dpmppm)(2)](4+) core in which the Ag(4) strings are rather bent with two dpmppm ligands arranged in a syn fashion, complexes 4-7 have linear Ag(4) strings supported by two dpmppm ligands arranged in an anti fashion. These results suggest that the dpmppm -supported tetrasilver(I) strings are quite flexible and labile and thus are potentially important in promoting organic reactions as a result of the multimetallic centers. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009), WILEY-V C H VERLAG GMBH, Nov. 2009, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (32), 4820 - 4829, doi;web_of_science

    Scientific journal

  • Interconversion between ladder-type octanuclear and linear tetranuclear copper(I) complexes supported by tetraphosphine ligands

    Yukie Takemura; Takayuki Nakajima; Tomoaki Tanase

    Linearly ordered tetraphosphine, meso-bis[(diphenylphosphinomethyl)phenylphosphino]methane(dpmppm), readily reacted with 4 equiv. of CuX in dichloromethane to afford octanuclear copper(I) complexes, [Cu(8)(mu-X)(8)(mu-dpmppm)(2)] (X = Cl (1a), Br (1b), I (1c)), which involve a ladder-type {Cu(8)(mu-X)(2)(mu 3-X)(6)} core supported by two dpmppm ligands in anti arrangement. Complex 1a was further transformed by treatment with Cu(OTf)(2) into [Cu(8)(mu-X)(6)(OTf)(2)(mu-dpmppm)(2)] (2) in which two TfO anions attached to both end of the Cu(8) ladder. When complexes 1 were dissolved in dimethyl sulfoxide (dmso) in the presence of 2 equiv. of dpmppm, the octacopper(I) ladder was unzipped to result in the linear tetranuclear copper(I) complex, [Cu(4)X(mu-X)(3)(mu-dpmppm)(2)(dmso)] (X = Cl (3a), Br (3b), I (3c)). Similar treatment of dpmppm with 2 equiv. of CuX in the presence of coordinative solvents, N,N'-dimethylformamide (dmf) and pyridine (py), yielded the symmetrical tetracopper(I) complexes, [Cu(4)(mu-Cl)(3)(mu-dpmppm)(2)(dmf)(2)][CuCl(2)] (4) and [Cu(4)(mu-I)(3)(mu-dpmppm)(2)(py)(2)]I (5). A series of tetracopper(I) complexes with terminal isocyanide ligands, [Cu(4)(mu-X)(3)(mu-dpmppm)(2)(RNC)(2)]PF(6) (X = Cl, R = Xyl (6a); X = Br, R = Mes (7b); X = I, R = Xyl (8a), Mes (8b), (t)Bu (8c)), were obtained from reactions of dpmppm with 2 equiv. of CuX in dmf or acetonitrile followed by addition of an excess of RNC and NH(4)PF(6). Complexes 3-8 possess a bending Cu(4)(mu-X)(3) chain supported by two dpmppm ligands in syn arrangement, where the terminal sites are reactive and accommodate a variety of terminal ligands. When complex 8c was treated with AgPF(6) in a CH(3)CN-CH(2)Cl(2) mixed solvent, the soft Lewis acidic Ag(I) ions took the copper(I)-binding dpmppm off and the resultant two {Cu(4)(mu-I)(3)(mu-dpmppm)((t)BuNC)(2)}(+) fragments were zipped up to form the ladder-type octacopper(I) complex, [Cu(8)(mu-I)(6)(mu-dpmppm)(2)((t)BuNC)(2)](PF(6))(2) (9). The apparent interconversion between the Cu(8) ladder and the Cu(4) chain might proceed through a labile intermediate with a {Cu(4)(mu-X)(3)(mu-dpmppm)}(+) unit, which could be useful synthon of further extended copper(I) halide clusters., ROYAL SOC CHEMISTRY, 2009, DALTON TRANSACTIONS, (46), 10231 - 10243, doi;web_of_science;url

    Scientific journal

  • Dynamic structural changes of pentacopper(II) chains supported by N-6-donor ligands

    Yukie Takemura; Takayuki Nakajima; Tomoaki Tanase; Miho Usuki; Hiroe Takenaka; Eri Goto; Masahiro Mikuriya

    Elastic pentacopper molecular chains, [Cu-5(panapy)(4)X-2] (X = Cl (1), Br (2)) and [Cu-5(panapy)(4)]X'(2) (X' = BF4 (3), PF6 (4)), were prepared using a naphthyridine-modulated N-6-donor ligand, panapy(2-), and showed magnetically coupled, dynamic rearrangement of five Cu(II) ions switched by the presence/absence of halide termination., ROYAL SOC CHEMISTRY, 2009, CHEMICAL COMMUNICATIONS, (13), 1664 - 1666, doi;web_of_science

    Scientific journal

  • Hexa- and Octagold Chains from Flexible Tetragold Molecular Units Supported by Linear Tetraphosphine Ligands

    Yukie Takemura; Hiroe Takenaka; Takayuki Nakajima; Tomoaki Tanase

    WILEY-V C H VERLAG GMBH, 2009, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 48 (12), 2157 - 2161, doi;web_of_science

    Scientific journal

  • Phosphine-dependent stereoselective nucleophilic reaction to bicyclic bis-mu-dichloro-eta(3)-allylpalladium complexes

    Ryohei Ogawa; Takayuki Nakajima; Isao Shimizu

    The effects on ligands in nucleophilic reaction of eta(3)-allylpalladium chloride dimers were studied. Reaction of steroid 1 with Na2PdCl4 in concentrated HCl under CO gave the cis,trans-bis-mu-dichloro-eta(3)-allylpalladium complex 2 after recrystallization. Reaction of 2 with malonate anion in the presence of PPh3 afforded trans-3 in 65% yield. When Dppe was used, cis-3 was obtained as the major product. In nucleophilic reactions of bicyclic eta(3)-allylpalladium chloride complex 4a or 4b with PPh3, cis-5 was the major product. However, the reaction with Dppe gave trans-5 predominantly. The stereochemistry in the nucleophilic reaction of eta(3)-allylpalladium chloride dimer is dependent on the added phosphines., CHEMICAL SOC JAPAN, Mar. 2008, CHEMISTRY LETTERS, 37 (3), 278 - 279, doi;web_of_science

    Scientific journal

  • Enantioselecitve elimination of Pd-H from eta(3)-allylpalladium-Tol BINAP complexes. Evidence of syn elimination pathway

    Ryohei Ogawa; Yusuke Shigemori; Koichi Uehara; Jiro Sano; Takayuki Nakajima; Isao Shimizu

    The palladium-catalyzed elimination of the bicyclic cis-acetate 1b using Pd catalyst and (R)-p-Tol BINAP gave the (S)-diene 2 with 58% ee. Bicyclic eta(3)-allylpalladium complex 3a with (R)-p-Tol BINAP, considered as an intermediate in the catalytic reaction from 1b, was prepared. Enantioselectivity in decomposition of 3a is dependent on the reaction conditions. The thermal decomposition of 3a without base gave the (S)-2 with 70% ee. However, the decomposition of 3a in the presence of excess base gave (R)-2 with 58% ee. Syn elimination from 3a was found to proceed preferentially from the decomposition results of the deuterium-labeled complexes., CHEMICAL SOC JAPAN, Nov. 2007, CHEMISTRY LETTERS, 36 (11), 1338 - 1339, doi;web_of_science

    Scientific journal

  • Reactivities governed by a single metal atom M in mixed-metal highnuclearity clusters having [Ru5M(C)] core (M = Co, Rh, Pd): Site-nonselective, site-selective, and chemo-selective variations in the SO2-trapping reactions

    Takayuki Nakajima; Hiromi Konomoto; Haruo Ogawa; Yasuo Wakatsuki

    The SO2 substitution for a CO ligand of the hexa-nuclear carbonyl complexes having Ru5M(C) type carbido-metal core, [PPN][Ru5CO(C)(CO)(16)] (2), [PPN][Ru5Rh(C)(CO)(16)] (3), and Ru5Pd(C)(CO)(16) (4), is dramatically affected by the kind of metal atom M: 2 (M = Co) is reactive but not site-selective, 3 (M = Rh) is reactive and site-selective, whereas 4 (M = Pd) is not reactive at all even though 4 can easily react with PPh3 to give the substitution products. (C) 2007 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA, Oct. 2007, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 692 (22), 4886 - 4894, doi;web_of_science

    Scientific journal

  • Synthesis of three-component high nuclearity cluster complexes with ruthenium carbido carbonyl clusters as a building block

    Takayuki Nakajima; Hiromi Konomoto; Haruo Ogawa; Yasuo Wakatsuki

    Treatment of AgNO3 with the Rh-Ru and Cu-Ru hetero bimetallic clusters, [PPN][RhRu5C(CO)(14)(cod)] and [PPh4](2)[CuRu6C(CO)(16)Cl], afforded novel three-component complexes having one silver-, and two silver-bridges between respective cluster units, [PPN]{Ag[RhRu5C(CO)(14)(cod)](2)} and [PPh4](2){Ag-2[CuRu6C(CO)(16)Cl](2)), respectively. Reaction of the ruthenium-copper cluster [PPh4](2) (Cu-4[Ru6C(CO)(16)]2Cl(2)} (6) with Pd-2(dba)(3)center dot CHCl3 gave another three-component cluster [PPh4](2) {Cu4Pd2[Ru6C(CO)(16)](2)Cl-2} by incorporation of two palladium atoms. However, a similar reaction of 6 with Pt(dba)(2) gave only a two-component cluster complex, [PPh4](2){Pt-2[Ru6C(CO) (15)](2)}, while the reaction of silver analog [PPN](2){Ag-4[Ru6C(CO)(16)](2)Cl-2} with Pd-2(dba)(3)center dot CHCl3 resulted in the formation of known ruthenium-palladium cluster [PPN](2){Pd-4[Ru6C(CO)(16)](2)}. Treatment of 6 with [RhCl(CO)(2)](2) gave two two-component clusters, [PPh4][RhRu5C(CO)(16)] and [PPh4](2){Cu-7[Ru6C(CO)(15)](2)Cl-3). All the new mixed-metal high nuclearity clusters have been characterized by single crystal X-ray analyses. @ 2007 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA, Oct. 2007, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 692 (22), 5071 - 5080, doi;web_of_science

    Scientific journal

  • Synthesis of isotope-labelled [1-C-13]-amino acids from (CO2)-C-13

    Takayuki Nakajima; Kazuki Nakayama; Isao Shimizu

    JOHN WILEY & SONS LTD, Apr. 2007, JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS, 50 (5-6), 622 - 623, doi;web_of_science

    Scientific journal

  • Synthesis, redox, and magnetic properties of a neutral, mixed-valent heptanuclear manganese wheel with S=27/2 high-spin ground state

    Rolf W. Saalfrank; Andreas Scheurer; Raju Prakash; Frank W. Heinemann; Takayuki Nakajima; Frank Hampel; Roland Leppin; Bernd Pilawa; Holger Rupp; Paul Mueller

    Reaction of lithium tetrachloromanganate(II) with N-n-butyldiethanolamine H2L3 (3) in the presence of LiH leads to the formation of wheel-shaped, mixed-valent heptanuclear, neutral complex {Mn-II subset of[(Mn2Mn4Cl6)-Mn-II-Cl-III(L-3)(6)]} (4). The manganese wheel crystallizes in the triclinic space group P (1) over bar as 4 center dot 2CHCl(3) or 4 center dot 3THF when either diethyl ether or n-pentane was allowed to diffuse into solutions of 4 in chloroform or tetrahydrofuran. The oxidation states of each manganese ion in 4 center dot 2CHCl(3) or 4 center dot 3THF were assigned on the basis of detailed symmetry, bond length, and charge considerations, as well as by the Jahn-Teller axial elongation observed for the manganese(III) ions, and were further supported by cyclic voltammetry. The analysis of the SQUID magnetic susceptibility data for complex 4 center dot 2CHCl(3) showed that the intramolecular magnetic coupling of the manganese(II,III) ions is dominated by ferromagnetic exchange interactions. This results in an S = 27/2 ground-state multiplet at low magnetic field. At fields higher than 0.68 T, the energetically lowest state is given by the m(S) = 31/2 component of the S = 31/2 multiplet due to the Zeeman effect. The ligand-field-splitting parameters were determined by anisotropy SQUID measurements on single crystalline samples along the crystallographic x, y, and z axes (D = -0.055 K, E = 6.6 mK) and by high-frequency electron spin resonance measurements on a polycrystalline powder of 4 center dot 2CHCl(3) (D = -0.068 K, E = 9.7 mK). The resulting barrier height for magnetization reversal amounts to U approximate to 10 K. Finally, 2DEG Hall magnetization measurements revealed that 4 center dot 2CHCl(3) shows single-molecule magnet behavior up to the blocking temperature of about 0.6 K with closely spaced steps in the hysteresis because of the quantum tunneling of the magnetization., AMER CHEMICAL SOC, Mar. 2007, INORGANIC CHEMISTRY, 46 (5), 1586 - 1592, doi;web_of_science

    Scientific journal

  • Short Step Synthesis of Natural 2-Arylquinolones Based on Iridium-Catalyzed Three-Component Coupling Quinoline Synthesis

    T. Nakajima; T. Inada; I. Shimizu

    Jul. 2006, Heterocycles, 69, 497 - 504, doi

    Scientific journal

  • Synthesis of beta-amino ketones by iridium(III)-catalyzed direct-Mannich reaction

    Shunsuke Sueki; Takeyuki Igarashi; Takayuki Nakajima; Isao Shimizu

    The direct-Mannich reaction of ketones 1, aldehydes 2, and anilines 3 was studied using catalytic amount of transition-metal complexes. The trivalent iridium complex, [IrCl2(H)(cod)](2), catalyzed the direct-Mannich reaction effectively to give various beta-amino kenotes in good yields under mild conditions., CHEMICAL SOC JAPAN, Jun. 2006, CHEMISTRY LETTERS, 35 (6), 682 - 683, doi;web_of_science

    Scientific journal

  • Facile three-component synthesis of substituted quinolines catalyzed by iridium(III) complex

    Takayuki Nakajima; Takashi Inada; Takeyuki Igarashi; Tadashi Sekioka; Isao Shimizu

    A convenient and efficient synthesis of substituted quinolines via a simple one-pot reaction of an aniline, an aromatic aldehyde, and an enolizable aliphatic aldehyde in the presence of the iridium catalyst [IrCl 2H(cod)]2 under oxygen as an oxidant was developed. The reaction proceeds with Mannich-type imine formation followed by nucleophilic addition to give β-amino aldehydes. Dehydrative cyclization takes place to give dihydroquinoline, which is then dehydrogenated by aerobic oxidation to give 2-aryl-3-alkylquinolines. Dialkylquinolines were obtained by the reaction with anilines and aliphatic aldehydes in good yields. © 2006 The Chemical Society of Japan., 2006, Bulletin of the Chemical Society of Japan, 79 (12), 1941 - 1949, doi

    Scientific journal

  • One-step synthesis of ethyl quinaldates by lewis acid catalyzed three-component coupling reaction of aromatic amines, aliphatic aldehydes and ethyl glyoxylate

    Takashi Inada; Takayuki Nakajima; Isao Shimizu

    A convenient, efficient and simple one-pot method for the synthesis of quinaldates was developed by three-component coupling reaction of an arylamine (1), ethyl glyoxylate and an aliphatic aldehyde (2) in the presence of Lewis acid catalyst. The reaction proceeded most effectively using Yb(OTf)3 as a catalyst. © 2005 The Japan Institute of Heterocyclic Chemistry., 31 Dec. 2005, Heterocycles, 66 (1), 611 - 619, doi

    Scientific journal

  • Syntheses and properties of metal-centered mixed-valent [NEt4]{Mn-II subset of[(Mn3Mn3Cl6)-Mn-II-Cl-III(L)6]} manganese wheels

    RW Saalfrank; T Nakajima; N Mooren; A Scheurer; H Maid; F Hampel; C Trieflinger; N Daub

    Upon reaction of N-substituted diethanolamines H2L2-4 (4,6, 7) with cesium carbonate and bis(tetraethylammonium) tetrachloromanganate(II) in acetonitrile in the presence of air, the metal-centered mixed-valent manganese wheels [NEt4]{Mn-II subset of[(Mn3Mn3Cl6)-Mn-II-Cl-III(L2-4)(6)]} (8-10) were generated. X-ray crystallographic structure analyses revealed, that 8-10 are principally isostructural and consist of an alternating ring of three Mn-II and three Mn-III ions, centered by an additional Mn-II ion. The cyclic voltammograms of 8 and 10 displayed three quasi-reversible oxidation processes, which are attributed to the subsequent one electron-oxidations of the three peripheral Mn-II ions to Mn-III. Oxidation of the central Mn-II ion is not observed within the applied potential. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)., WILEY-V C H VERLAG GMBH, Mar. 2005, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (6), 1149 - 1153, doi;web_of_science

    Scientific journal

  • One-pot synthesis of substituted quinolines by iridium-catalyzed three-component coupling reaction

    T Igarashi; T Inada; T Sekioka; T Nakajima; Shimizu, I

    A convenient and efficient synthesis of substituted quinolines in a simple one-pot reaction of an arylamine 1, an aromatic aldehyde or aliphatic aldehyde 2 and an aliphatic aldehyde 3 in the presence of transition metal complexes or Lewis acids was developed. Among them, the iridium catalyst [Ir(cod)Cl](2) catalyzed the reaction most efficiently., CHEMICAL SOC JAPAN, Jan. 2005, CHEMISTRY LETTERS, 34 (1), 106 - 107, doi;web_of_science

    Scientific journal

  • Six-membered metalla-coronands. Synthesis and crystal packing: Columns, compartments, and 3D-networks

    RW Saalfrank; C Deutscher; S Sperner; T Nakajima; AM Ako; E Uller; F Hampel; FW Heinemann

    Reaction of various N-substituted diethanolamines H2L3 (4) with calcium hydride and iron(III) chloride leads to the self-assembly of six-membered ferric wheels [Fe6X6(L-3)(6)] (5). Principally, all the iron coronands are isostructural; however, they differ fundamentally with respect to their crystal packing. Exemplarily, this is discussed for selected members of the space groups R(3)over bar, P(3)over bar, P2(1)/c, P2(1)/n, C2/c, and P(1)over bar. Depending on the nature of their sidearms, the ferric wheels create various substructures. For instance, the ferric wheels 5a-i of space group R(3)over bar or P(3)over bar are piled in parallel in cylindrical columns, which are surrounded by six parallel columns alternately dislocated by 1/3c and 2/3 c against the central one. Pronounced van der Waals interactions give rise to compartmentation and incarceration of guest molecules as seen for 5e,g. However, in 5h strong pi-pi interactions create a three-dimensional scaffold, The most significant difference of the ferric wheels 5j-p of space groups P2(1)/c, P2(1/)n, and C2/c is that these ferric wheels are arranged in parallel in two orientations. They differ mainly only by the included angle of the two groups of parallel wheels. In the case of 51, molecular chains are formed in the crystal due to pi-pi interactions. The ferric wheels 5q-y of space group P(1)over bar are packed in the crystal most simply, with all the ferric wheels piled in parallel., AMER CHEMICAL SOC, Jul. 2004, INORGANIC CHEMISTRY, 43 (14), 4372 - 4382, doi;web_of_science

    Scientific journal

  • Synthesis, structure, and dynamics of six-membered metallacoronands and metallodendrimers of iron and indium

    RW Saalfrank; C Deutscher; H Maid; AM Ako; S Sperner; T Nakajima; W Bauer; F Hampel; BA Hess; NJRV Hommes; R Puchta; FW Heinemann

    In the reaction of the N-substituted diethanolamines (H2L1-3) (1-3) with calcium hydride followed by addition of iron(m) or indium(m) chloride, the iron wheels [Fe6Cl6(L-1)(6)] (4) and [Fe6Cl6(L-2)(6)] (6) or indium wheels [In6Cl6(L-1)(6)] (5), [In6Cl6(L-2)(6)] (8) and [In6Cl6(L-3)(6)] (9) were formed in excellent yields. Exchange of the chloride ions of 6 by thiocyanate ions afforded [Fe-6(SCN)(6)(L-2)(6)] (7). Whereas the structures of 4, 5 and 7 were determined unequivocally by single-crystal X-ray analyses, complexes 8 and 9 were characterised by NMR spectroscopy. Contrary to what is normally presumed, the scaffolds of six-membered metallic wheels are not generally rigid, but rather undergo nondissociative topomerisation processes. This was shown by variable temperature (VT) H-1 NMR spectroscopy for the indium wheel [In6Cl6(L-1)(6)] (5) and is highlighted for the enantiotopomerisation of one indium centre {1/6[S-6-5] reversible arrow 1/6[S-6-5']}. The self-assembly of metallic wheels, starting from diethanolamine dendrons, is an efficient strategy for the convergent synthesis of metallodendrimers., WILEY-V C H VERLAG GMBH, Apr. 2004, CHEMISTRY-A EUROPEAN JOURNAL, 10 (8), 1899 - 1905, doi;web_of_science

    Scientific journal

  • Self-assembly and crystal hetero-octametallic molecular box structure of a novel (Chelate complexes, Part 23)

    RW Saalfrank; Bernt, I; F Hampel; A Scheurer; T Nakajima; SHZ Huma; FW Heinemann; M Schmidtmann; A Muller

    Reaction of hexadentate ligand m-xylene-bis-(iminodiethanol) H4L2 (4) with lithium hydride and either copper(II) acetate or copper(II) chloride resulted in the formation of two completely different products. Starting from copper(II) acetate the green bis-dimetallic cyclophane [Cu-4(H2L22)(OAc)(4)](.)2CH(2)Cl(2) (5) was formed. However, when 4 was allowed to react with copper(II) chloride, the novel hetero-octametallic molecular box {[Li-4(Cu4O)(L-2)(2)](H2O)(2)(EtOH)(2)}Cl-2 (6) was isolated. Deep violet 6 can be described as two metallacrown ether sub-units linked together by a central mu(4)-bridging O-2(-)-ion. The structures of all new compounds were determined unequivocally by single crystal X-ray analyses. (C) 2003 Elsevier Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, Oct. 2003, POLYHEDRON, 22 (22), 2985 - 2989, doi;web_of_science

    Scientific journal

  • Nitric oxide reduction by carbon monoxide over supported hexaruthenium cluster catalysts. 1. The active site structure that depends on supporting metal oxide and catalytic reaction conditions

    T Minato; Y Izumi; K Aika; A Ishiguro; T Nakajima; Y Wakatsuki

    Ruthenium site structures supported on metal oxide surfaces were designed by reacting organometallic Ru cluster [Ru6C(CO)(16)](2-) or [Ru-6(CO)(18)](2-) with various metal oxides,TiO2, Al2O3, MgO, andSiO(2). The surface Ru site structure, formed under various catalyst preparation and reaction conditions, was investigated by the Ru K-edge extended X-ray absorption fine structure (EXAFS). Samples of [RU6C(CO)(16)](2-)/TiO2(anatase) and [RU6C(CO)(16)](2-)/TiO2(rutile) were found to retain the original RU6C framework when heated in the presence of NO (2.0 kPa) or NO (2.0 kPa) + CO (2.0 kPa) at 423 K, i.e., catalytic reaction conditions for NO decomposition. At 523 K, the Ru-Ru bonds of the RU6C framework were cleaved by the attack of NO. In contrast, the Ru site became spontaneously dispersed over TiO2 (anatase). When being supported over TiO2 (mesoporous), MgO, or Al2O3, the Ru6C framework split into fragments in gaseous NO or NO + CO even at 423 K. The Ru-6 framework of [RU6(CO)(18)](2-) was found to break easily into smaller ensembles in the presence of NO and/or CO at 423 K on support. Taking into consideration the realistic environments in which these catalysts will be used, we also examined the effect of water and oxygen. When water was introduced to the sample [RU6C(CO)(16)](2-)/TiO2(anatase) at 423 K, it did not have any effects on the stabilized RU6C framework structure. In the presence of oxygen gas, however, the Ru hexanclear structure decomposed into isolated Ru cations bound to surface oxygen atoms of TiO2 (anatase)., AMER CHEMICAL SOC, Aug. 2003, JOURNAL OF PHYSICAL CHEMISTRY B, 107 (34), 9022 - 9028, doi;web_of_science

    Scientific journal

  • Nitric Oxide Reduction by Carbon Monoxide over Supported Hexaruthenium Cluster Catalysts. 1. The Active Site Structure that Depends on Supporting Metal Oxide and Catalytic Reaction Conditions

    若槻 康雄; Minato, T; Izumi, Y; Aika, K; Ishiguro, A; Nakajima, T; Wakatsuki, Y

    2003, J. Phys. Chem., 107 (34), 9022 - 9028, doi;cinii_articles

  • Structural Study of the Effects of Water and Oxygen on the Nitric Oxide Decomposition on [Ru6C]/TiO2 Catalysts

    Taketoshi Minato; Yasuo Izumi; Ken-ichi Aika; Atsushi Ishiguro; Takayuki Nakajima; Yasuo Wakatsuki

    2003, Photon Factory Activity Report 2001, 19B, 18 - 18, url

  • Nanoparticles of amorphous ruthenium sulfide easily obtainable from a TiO2-supported hexanuclear cluster complex [Ru6C(CO)(16)](2-): A highly active catalyst for the reduction of SO2 with H-2

    A Ishiguro; T Nakajima; T Iwata; M Fujita; T Minato; F Kiyotaki; Y Izumi; K Aika; M Uchida; K Kimoto; Y Matsui; Y Wakatsuki

    TiO2-supported ruthenium-metal particles were derived from an anionic hexanuclear carbido carbonyl cluster [Ru6C(CO)(16)](2-) and compared with those prepared conventionally by impregnation of TiO2 with a solution of RuCl3 followed by reduction with H-2. The average sizes of the metal particles in both systems are similar, that is, 12 Angstrom for molecular cluster-derived particles and 15 Angstrom for those derived from the RuCl3 precursor, although the size distribution is sharper in the former case. These supported particles efficiently promote the reduction of SO2 with H-2 to give elemental sulfur. Their active form is ruthenium sulfide as confirmed by EXAFS and X-ray diffraction measurements. The nanoscale ruthenium sulfide particles, which originated from the cluster complex, have an amorphous character and show activity even at low temperature (463 K), whereas ruthenium sulfide formed from RuCl3-derived metal dispersion is a pyrite-type RuS2 crystallite and needs a temperature above 513 K to effect the same catalysis. Amorphous ruthenium sulfide maintains its nano-sized scale (approximate to 14 Angstrom) regardless of the reaction temperature, while RuS2 crystallite aggregates to form larger nonuniform particles., WILEY-V C H VERLAG GMBH, Jul. 2002, CHEMISTRY-A EUROPEAN JOURNAL, 8 (14), 3260 - 3268, doi;web_of_science

    Scientific journal

  • Efficient reduction of sulfur dioxide with hydrogen over TiO2-supported catalysts derived from ruthenium salts and ruthenium cluster complexes

    A Ishiguro; Y Liu; T Nakajima; Y Wakatsuki

    Catalytic reduction of SO2 to elemental sulfur was carried out over supported ruthenium catalysts that were derived not only from hexaruthenium carbonyl cluster complexes but also from RuCl3 as the precursor. The activity was largely dependent on the kind of metal oxide support used. Compared to the known systems, the TiO2-supported ruthenium catalysts operated with higher efficiency at lower temperature. Moreover, the selectivity was totally to elemental sulfur, forming no detectable amount of unfavorable H2S. H2S-free catalysis appeared to be a common feature of ruthenium catalysts regardless of the kind of precursors. The TiO2-supported catalyst derived from [N(PPh3)(2)](2)[Ru6C(CO)(16)] was much more active within the 463-508 K temperature region than the catalyst conventionally prepared from RuCl3, while both showed similar activity at more elevated temperatures. The kind of cation in anionic cluster complexes and the presence of an interstitial atom are important factors in generating supported catalysts that operate under mild conditions. (C) 2002 Elsevier Science (USA)., ACADEMIC PRESS INC ELSEVIER SCIENCE, Feb. 2002, JOURNAL OF CATALYSIS, 206 (1), 159 - 164, doi;web_of_science

    Scientific journal

  • Supported ruthenium carbido-cluster catalysts for the catalytic removal of nitrogen monoxide and sulfur dioxide: the preparation process monitored by sulfur K-edge X-ray absorption near-edge structure

    Y Izumi; T Minato; K Aika; A Ishiguro; T Nakajima; Y Wakatsuki

    The preparation process of ruthenium carbido-cluster catalysts for the reduction of sulfur dioxide was traced by means of sulfur K-edge X-ray absorption near-edge structure (XANES). During the activation process, a pair of peaks at 2472.5 - 2472.8 and 2482.7 - 2482.8 eV appeared. The pair was ascribed to the M, phase. Once the catalysts were activated at 503 - 573 K, another pair of peaks at 2474.2 and 2479.2 eV appeared. The pair was assigned to the pi* and sigma* transition peaks, respectively, of adsorbed SO2 molecules on the catalyst surface., ELSEVIER SCIENCE BV, 2002, SCIENTIFIC BASES FOR THE PREPARATION OF HETEROGENEOUS CATALYSTS, 143, 361 - 368, doi;web_of_science

    Scientific journal

  • Formation of super wires of clusters by self assembly of transition metal cluster anions with metal cations

    T Nakajima; A Ishiguro; Y Wakatsuki

    WILEY-V C H VERLAG GMBH, 2001, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 40 (6), 1066 - +, doi;web_of_science

    Scientific journal

  • Synthesis of mixed-metal high-nuclearity clusters by fusion of anionic ruthenium carbido clusters through palladium units

    T Nakajima; A Ishiguro; Y Wakatsuki

    WILEY-V C H VERLAG GMBH, 2000, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 39 (6), 1131 - +, doi;web_of_science

    Scientific journal

  • Synthesis of triangular and tetrahedral heteronuclear metal clusters using hydride complexes of cyclopentadienylrhodium and -ruthenium as the precursors

    T Nakajima; Shimizu, I; K Kobayashi; Y Wakatsuki

    Photochemical and/or thermal reactions of Cp*Rh(H)(2)(SiEt3)(2) (Cp* = eta(5)-C5Me5) with the dimeric metal complexes [CpNi(CO)](2) (Cp = eta(5)-C5H5), [CpCo(NO)](2), [CpRu(CO)(2)](2), and [CpFe(CO)(2)](2) yielded the trinuclear complexes (Cp*Rh)(CpNi)(2)(CO)(2) (3), (Cp*Rh)(CpCo)(2)(NO)(2) (4), (Cp*Rh)(CpM)(2)(CO)(4) (5a, M = Ru; 5b, M = Fe), respectively, while the reaction with [CpMo(CO)(2)](2) gave the tetranuclear unsaturated complex (Cp*Rh)2(CpMo)2(CO)4 (6) in good to moderate yields, Similarly, [Cp*Ru](2)(mu-H)(4) reacted with [CpNi(CO)](2), CpCo(CO)(2), and [CpFe(CO)(2)](2) to give tetrahedral (Cp*Ru)(2)(CpNi)(2)(CO)(2) (7), triangular (Cp*Ru)(2)(CpCo)(CO)(4) (8), and tetrahedral (Cp*Ru)(2)(CpFe)(2)(CO)(4) (9) complexes, respectively. The mixed-metal clusters 3, 4, 5a, and 6-9 have been structurally characterized by single-crystal X-ray diffraction., AMER CHEMICAL SOC, Jan. 1998, ORGANOMETALLICS, 17 (2), 262 - 269, doi;web_of_science

    Scientific journal

  • Facile P-C bond cleavage of trimethylphosphine at a heterodimetallic (Ni-W) center

    T Nakajima; Shimizu, I; K Kobayashi; H Koshino; Y Wakatsuki

    AMER CHEMICAL SOC, Dec. 1997, INORGANIC CHEMISTRY, 36 (27), 6440 - 6442, doi;web_of_science

    Scientific journal

  • Facile synthesis of keto nitriles by Cu(II)-promoted photooxidative cleavage of cyclic olefins

    Shimizu, I; M Fujita; T Nakajima; T Sato

    Reaction of trisubstituted cyclic olefins with NaN3 in the presence of Cu(OTf)(2) upon irradiation under oxygen gave keto nitriles in good yields. 1,5-Dimethyl-1,5-cyclooctadiene and 1,5,9-trimethyl-1,5,9-cyclododecatriene were converted into the corresponding unsaturated keto nitriles., GEORG THIEME VERLAG, Aug. 1997, SYNLETT, (8), 887 - &, doi;web_of_science

    Scientific journal

  • Molybdenum-catalyzed aromatic substitution with olefins and alcohols

    Shimizu, I; KM Khien; M Nagatomo; T Nakajima; A Yamamoto

    A new type of electrophilic aromatic substitution without using organic halides has been realized by using Mo(CO)(6) catalyst., CHEMICAL SOC JAPAN, 1997, CHEMISTRY LETTERS, 26 (9), 851 - 852, doi;web_of_science

    Scientific journal



    Irradiation of a mixture of tungstenocene or molybdenocene dihydride and a metal-metal-bonded dimeric complex has been found to be a convenient route to homo- and heterometallic complexes. The photoreactions of (eta(5)-C5H5)(2)M(1)H(2) With [(eta(5)-C5H5)M(2)(CO)(3)](2) (M(1), M(2) = W, Mo) in DME afford in good yields the bimetallic complexes (eta(5)-C5H5)(CO)M(1)(mu,sigma-eta(5)-C5H4)-M(2)(CO)(2)(eta(5)-C5H5) with a M(1)-M(2) bond. (1a, M(1) = W, M(2) = Mo; 1b, M(1) = Mo, M(2) = W; 1C, M(1) = M(2) = W; 1d, M(1) = M(2) = MO). BY use of [(eta(5)-C(5)R(5))Ni(CO)](2) as the dimer part, the heterobimetallic hydrides (eta(5)-C5H5)(2)M(mu-H)(mu-CO)Ni(C(5)R(5)) (2a, M = W, R = H; 2b, M = W, R = Me; 2c, M = Mo, R = H, 2d, M = Mo, R = Me) were obtained, where the two metallocene cyclopentadienyl rings remain intact and the metal-metal bond is bridged by CO and hydride. Similar photolysis of a mixture of (eta(5)-C5H5)(2)MH(2) and [(eta(5)-C5H5)Ru(CO)(2)](2) has afforded two trimetallic complexes: (eta(5)-C5H5)(mu,sigma-eta(5)-C5H4)M(mu-CO)(2)Ru(eta(5)-C5H5)Ru(eta(5)-C5H5)-(CO)H (3a, M = W; 3b, M = Mo), where the Ru-Ru bond still exists with a new M-Ru bond and one bridging (mu,sigma-eta(5)-C5H4) ring between M and the other Ru, and (mu,sigma-eta(5)-C5H4)(2)-Mh(2)[(eta(5)-C5H5)Ru(CO)](2) (4a, M = W; 4b, M = Mo), in which both of the cyclopentadienyl rings of the metallocene are metalated with Ru. The crystal and molecular structures of 1a, 2d, 3a, and 4a have been determined by single-crystal X-ray diffraction analysis., AMER CHEMICAL SOC, Dec. 1995, ORGANOMETALLICS, 14 (12), 5598 - 5604, doi;web_of_science

    Scientific journal



    Bridged-bis(cyclopentadienyl) molybdenum and tungsten dihydrides and their derivatives have been synthesized for the first time. [(1,1,3,3-Tetramethyldisiloxane-1,3-diyl)bis(eta5-cyclopentadienyl)]molybdenum dihydride (1a) and tungsten dihydride (1b) were prepared by sodium borohydride reduction of [O(SiMe2C5H4)2]MCl2 (2a: M = Mo, 2b: M = W) which was obtained by the reaction of disodium 1,1,3,3-tetramethyl-1,3-bis(cyclopentadienyl)disiloxane with MCl4(thf)2 (M = Mo, W). The dichlorides 2 reacted with ZnMe2 and NaSEt to afford [O(SiMe2C5H4)2]MMe2 (3a: M = Mo, 3b: M = W) and [O(SiMe2C5H4)2]M(SEt)2 (4a: M = Mo, 4b: M = W), respectively. Photolysis of lb in benzene gave [O(SiMe2C5H4)2]WH(C6H5) (5b). An X-ray crystal analysis of 3a has proved that the bridging chain blocks one of the side positions of the complex, the siloxy unit being present at one side of the Me-Mo-Me bisector. Consistent with side position attack by olefins, the reaction rate of la with methyl methacrylate was found to be nearly one half that of the parent CP2MoH2 (6a)., ELSEVIER SCIENCE SA LAUSANNE, Jun. 1994, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 473 (1-2), 155 - 162, doi;web_of_science

    Scientific journal

  • Chiral Octapalladium Chains Supported by Enantiopure P-Stereogenic Linear Tetraphosphines, (R,R)- and (S,S)-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2

    Tomoaki Tanase; Kanako Nakamae; Suzui Hayashi; Ayumi Okue; Risa Otaki; Tomoko Nishida; Yasuyuki Ura; Yasutaka Kitagawa; Takayuki Nakajima

    American Chemical Society (ACS), 01 Mar. 2021, Inorganic Chemistry, 60 (5), 3259 - 3273, doi;url

    Scientific journal


  • サイエンス・オープンラボを通した化学(電池の歴史、化学発光)学習ー大学生による演示実験を動機付けにした高等学校授業開発研究ー

    TAKASHIMA Hiroshi; TAKEUCHI Takae; MIKATA Yuji; URA Yasuyuki; NAKAJIMA Takayuki; MATSUURA Noriyuki

    Mar. 2019, 教育システム研究, (14), 103 - 111

  • 固定化ルテニウムクラスター触媒の調製とNO還元反応

    湊 丈俊; 泉 康雄; 秋鹿 研一; 吉武 英昭; 石黒 淳; 中島 隆行; 若槻 康雄

    触媒学会, 10 Mar. 2002, 觸媒 = Catalyst, 44 (2), 95 - 97, cinii_articles

  • Sulfur K-edge XAFS Study of Supported Ruthenium Cluster Catalysts

    Yasuo Izumi; Atsushi Ishiguro; Taketoshi Minato; Takayuki Nakajima; Yasuo Wakatsuki

    2002, Photon Factory Activity Report 2000, 18B, 38 - 38, url

    Report research institution

  • 担持ルテニウムクラスター触媒を用いたSO_2還元反応とXAFSによる触媒種のキャラクタリゼーション

    石黒 淳; 劉 宇; 中島 隆行; 湊 丈俊; 清瀧 史貴; 泉 康雄; 秋鹿 研一; 岩槻 康雄

    触媒学会, 10 Sep. 2001, 触媒, 43 (6), 382 - 384, cinii_articles

  • High-Nuclearity Cluster Complexes and Their Reaction with Air-Polluting SO2 Gas Molecules

    NAKAJIMA Takayuki; T. Nakajima; A. Ishiguro; Y. Liu; T. Chihara; Y. Wakatsuki

    2001, RIKEN Review, 42, 45 - 48

  • 1H-31P Pulsed Field Gradient Heteronuclear Multiple-Bond Correlation (PFG-HMBC) Spectroscopy

    中島 隆行; H. Koshino; T. Nakajima; Y. Wakatsuki; K. Kobayashi; J. Uzawa

    1996, RIKEN Review, 12, 37 - 38

  • 1H-31P Pulsed Field Gradient Heteronuclear Multiple-Bond Correlation (PFG-HMBC) Spectroscopy

    NAKAJIMA Takayuki; H. Koshino; T. Nakajima; Y. Wakatsuki; K. Kobayashi; J. Uzawa

    1996, RIKEN Review, 12, 37 - 38

Books etc

  • 第5版実験化学講座21有機遷移金属化合物、超分子錯体

    丸善, 2004

Association Memberships

  • 有機合成化学協会

  • 錯体化学会

  • 日本化学会

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