Faculty Profiles - SUZUKI Takayoshi

Papers - SUZUKI Takayoshi

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Preparation, Crystal Structures, and Behavior in Solution of Cobalt(III) Complexes Containing 2-Cyanoethylphosphines: trans-[Co(Me2dtc)(2){P(CH2CH2CN)(n)Ph3-n}]BF4 (n=1-3; Me(2)dtc(-): N,N-Dimethyldithiocarbamate)

Keiko Kihara, Takayoshi Suzuki, Masakazu Kita, Yukinari Sunatsuki, Masaaki Kojima, Hideo D. Takagi

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 85 ( 10 ) 1160 - 1166 2012.10

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

A series of cobalt(III) complexes containing 2-cyanoethylphosphines, [Co(Me(2)dtc)(2){P(CH2CH2CN)(n)Ph3-n}(2)]BF4 {Me(2)dtc(-): N,N-dimethyldithiocarbamate; n =1 (1), 2 (2), and 3 (3)} have been prepared, and their molecular structures in the crystals and in solution have been characterized. X-ray analysis revealed that all complexes isolated as single-crystals were the trans-isomers. The Co-P bond lengths for the 2-cyanoethylphosphines in complexes 1-3 are almost invariant to the number of 2-cyanoethyl substituent groups. Unlike related complexes with other monodentate P-donor ligands, complexes 1-3 in solution showed dissociation and isomerization equilibriums, which were achieved immediately after dissolving the crystals. These characteristic features of the complexes would result from the weak sigma-donor and pi-acceptor abilities of 2-cyanoethylphosphines. Furthermore, mixing of complex 1 and NaN3 in acetonitrile gave cis-[Co(Me(2)dtc)(2)(N-3){P(CH2CH2CN)Ph-2}] quantitatively, and refluxing the mixture resulted in the phosphine-tetrazolate complex, [Co(Me(2)dtc)(2)(Ph2PCH2CH2CN4-(KP)-P-2,N-1)] (4).

DOI： 10.1246/bcsj.20120148

Crystal structure and spectroscopic properties of trans-dichlorobis(1,3-propane-diamine)chromium(III) perchlorate

J. -H. Choi, A. Takayama, T. Suzuki

JOURNAL OF STRUCTURAL CHEMISTRY 53 ( 2 ) 397 - 402 2012.3

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

The crystal structure of trans-[Cr(tn)(2)Cl-2]ClO4 (tn = 1,3-propanediamine) is determined by a single-crystal X-ray diffraction study at 185 K. The Cr atom is in a slightly distorted octahedral environment coordinated by four nitrogen atoms of two tn ligands and two chlorine atoms in trans position. The orientations of two six-membered rings in the complex cation are in an anti chair-chair conformation with respect to each other. The mean Cr-N(tn) and Cr-Cl bond lengths are 2.0862(2) and 2.3112(6) respectively. The ClO (4) (-) anions have a slightly distorted tetrahedral geometry with Cl-O lengths and O-Cl-O angles influenced by the hydrogen bonding. The crystal packing is stabilized by several hydrogen bonds. The infrared and electronic absorption spectral properties are also described along with the results of X-ray crystallography.

DOI： 10.1134/S0022476612020291

Synthesis, Spectroscopic Studies, Crystal Structure and Electrochemical Properties of New Cobalt(III) Complex Derived from 2-Aminophenol and 4-(Dimethylamino) Cinnamaldehyde: Nano-Sized Complex Thin Film Formation via Surface Layer-by-Layer Chemical Deposition Method

Mohammad Hossein Habibi, Elahe Shojaee, Yuki Yamane, Takayoshi Suzuki

JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS 22 ( 1 ) 190 - 195 2012.1

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

New Schiff base (HL) ligand is prepared via condensation of 2-aminophenol and 4-(dimethylamino) cinnamaldehyde. The cobalt complex with the formula of [Co(L)(2)(MePy)(2)]PF6 is prepared in good yield from the reaction of the ligand with cobalt(II) acetate. The compounds were characterized by the analytical and spectroscopic methods. The ligand (HL) behaves as a bidentate ligand and coordinates to the cobalt ions via the nitrogen and oxygen atoms with mononuclear structure. The ligand (HL) has been structurally characterized by X-ray crystallography. There is O-H center dot center dot center dot N-H bond linking the molecules together. FT-IR spectra show that HL is coordinated to the cobalt ion in a mono-negative bidentate manner with ON donor sites of the azomethene N and deprotonated phenolic-OH. There are two methylpyridine molecules apically coordinated to Co(III) ion in octahedral environment. Electrochemical properties were investigated as metal centres in the dimethylformamide solvents. The Co(III) complex exhibit both irreversible reductive (CoIII/CoII; Epc, -1.24 V) and oxidative (CoII/CoIII; Epa, +0.79 V, respectively) responses in cyclic voltammetry. Thin film of nano-sized [M(L)(2)(MePy)(2)]PF6 complex was formed by surface layer-by-layer chemical deposition method. The formation of uniform thin films of nano-crystalline metal complex is dependent on metal and ligand concentrations.

DOI： 10.1007/s10904-011-9535-1

Conglomerate crystallization, chiral recognition and spin-crossover in a host-guest complex consisting of Fe-III complexes (host) and [Cr(ox)(3)](3-) (guest)

Yukinari Sunatsuki, Sho Miyahara, Yuu Sasaki, Takayoshi Suzuki, Masaaki Kojima, Naohide Matsumoto

CRYSTENGCOMM 14 ( 20 ) 6377 - 6380 2012

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

A host-guest complex, [Fe-III(H3L)][Fe-III(L)][Cr-III(ox)(3)]center dot 3H(2)O (1), where H3L and L3- serve as hexadentate ligands, was prepared. In 1, three properties are united: the homochiral assembly of chiral [Fe-III(H3L)](3+) and [Fe-III(L)] into a conglomerate structure, the chiral recognition of the host Fe-III assembly to the guest [Cr-III(ox)(3)](3-) and the spin-crossover of [Fe-III(H3L)](3+).

DOI： 10.1039/c2ce25612f

Syntheses, spectral, electrochemical and thermal studies of mononuclear manganese(III) complexes with ligands derived from 1,2-propanediamine and 2-hydroxy-3 or 5-methoxybenzaldehyde: Self-assembled monolayer formation on nanostructure zinc oxide thin film

Mohammad Hossein Habibi, Elham Askari, Mehdi Amirnasr, Ahmad Amiri, Yuki Yamane, Takayoshi Suzuki

SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 79 ( 3 ) 666 - 671 2011.8

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Mononuclear Mn(III) complexes have been prepared via the Mn(II) reaction of an equimolar of Schiff-bases derived from reaction of 2-hydroxy-3-methoxybenzaldehyde or 2-hydroxy-5-methoxybenzaldehyde with 1,2-diaminopropane. Axial ligands L include: pyridine (py) and H2O. The resulting complexes have been characterized by FT-IR and UV-vis spectroscopy. The crystal structures of the complexes were determined and indicate that in the solid state the complex adopts a slightly distorted octahedral environment of the imine N and hydroxo O with the two axial ligands. The electrochemical reduction of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Mn-III-Mn-II is electrochemically quasi-reversible. Thermal stability of these complexes was determined by TG and DTG. Layers of these complexes were formed on nanostructure zinc oxide thin film and a red shift was observed when zinc oxide thin film is modified by complex. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.saa.2011.03.055

Reactivities of the N-Atom-inserted Ligands, NSC(NR2)S2- and SN=C(NR2)S2-, in Iridium(III) Complexes

Keita Ariyoshi, Takayoshi Suzuki, James M. Mayer, Masaaki Kojima

CHEMISTRY LETTERS 40 ( 8 ) 831 - 833 2011.8

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Reactions of [Cp*Ir{NSC(NR2)S}] (Cp* = eta(5)-C5Me5, R = Me or Et,) with alkyl halides (MeI or BnBr) in acetonitrile gave the N-alkylated products, [Cp*Ir{R'NSC(NR2)S}] (R' = Me or Bn). These complexes readily reacted with PPh3 to give adducts. In contrast, [Cp*Ir{SN=C(NR2)S}] formed their PPh3 adducts, which gave thermally stable S-alkylated products by reactions with alkyl halides.

DOI： 10.1246/cl.2011.831

DFT study of molecular structure of 2-oxo-1,2,3,4-tetrahydropyrimidin-5-carboxamides and their corresponding oxidized forms 2-oxo-1,2-dihydropyrimidin-5-carboxamides

Hamid Reza Memarian, Hassan Sabzyan, Mousa Soleymani, Mohammad Hossein Habibi, Takayoshi Suzuki

JOURNAL OF MOLECULAR STRUCTURE 998 ( 1-3 ) 91 - 98 2011.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Density functional theory (DFT) at B3LYP/6-31++G** level has been applied to study structural, electronic and bonding characteristics of some 2-oxo-1,2,3,4-tetrahydropyrimidin-5-carboxamides (THPMs) and their oxidized forms 2-oxo-1,2-dihydropyrimidin-5-carboxamides (DHPMs). Results of this study show that for these THPMs, the six-member ring adopts a boat conformation with a pseudo-axial orientation of the C(4)-substituent. Experimental and theoretical (1)H NMR data obtained for THPMs and their corresponding oxidized forms (DHPMs) are correlated. Thermochemical analysis on THPMs and their corresponding oxidation products show that the oxidation reaction of THPMs to DHPMs is endothermic. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.molstruc.2011.05.017

Geometric Selectivity, Hydrogen-Bonding Interaction, and Solvatochromism of Bis{N-(aminoalkyl)salicylamidato(2-)}cobaltate(III)

Ryoji Mitsuhashi, Takayoshi Suzuki, Yukinari Sunatsuki, Masaaki Kojima

CHEMISTRY LETTERS 40 ( 7 ) 696 - 698 2011.7

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Cobalt(HI) complexes with N-(aminoalkyl)salicylamide dianions, Ln(2-) (n = 1-4), have been prepared and their molecular and crystal structures have been determined. The geometric (mer- or fac-) selectivity of [Co(Ln)(2)](-) complexes was dependent on the number of the amine-amidato chelate ring member. Intermolecular homochiral hydrogen-bonds and solvatochromic behavior of the complexes were also observed.

DOI： 10.1246/cl.2011.696

Orange and Yellow Crystals of Copper(I) Complexes Bearing 8-(Diphenylphosphino)quinoline: A Pair of Distortion Isomers of an Intrinsic Tetrahedral Complex

Takayoshi Suzuki, Hiroshi Yamaguchi, Akira Hashimoto, Koichi Nozaki, Mototsugu Doi, Naoya Inazumi, Noriaki Ikeda, Satoshi Kawata, Masaaki Kojima, Hideo D. Takagi

INORGANIC CHEMISTRY 50 ( 9 ) 3981 - 3987 2011.5

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

The tetrafluoroborate salt of bis{8-(diphenylphosphino)quinoline}copper(I), [Cu(Ph(2)Pqn)(2)]BF(4), afforded orange prismatic (2O) or yellow columnar (2Y) crystals, dependent on the solvent and concentration of the recrystallization solution used. X-ray analysis revealed that crystals of 2O and 2Y had the same composition and exhibited different crystal systems: 2O was triclinic, with space group P (1) over bar and Z = 2, and 2Y was monoclinic with space group P2(1)/c and Z = 4. In these crystals, the tetrahedral copper(I) complex exhibited a strong "rocking distortion" toward a trigonal pyramidal coordination geometry (by a slide translation of one of the unsymmetrical bidentate chelating ligands along the tetrahedral edge). In addition, both the 2O and 2Y complexes showed a "flattening distortion", meaning that the dihedral angle between the two chelate planes were off-perpendicular and oriented toward opposite directions, which resulted in a pair of distortion isomers: syn clinal (sc: 2O) and anti clinal (ac: 2Y). (31)P CP-MAS NMR spectroscopy indicated that 2O and 2Y could be distinguished. Both isomers exhibited inequivalent P atoms, but a larger difference in chemical shift was observed in 2Y. TD-DFT calculations reproduced the difference in spectra between the orange- and yellow-colored complexes, which originated from metal-to-ligand charge-transfer transitions.

DOI： 10.1021/ic1024636

A Polymorphic Platinum(II) Complex: Yellow, Red, and Green Polymorphs and X-ray Crystallography of [Pt(fdpb)Cl] [Hfdpb=1,3-Bis(5-trifluoromethyl-2-pyridyl)benzene]

Yuta Nishiuchi, Asuka Takayama, Takayoshi Suzuki, Kazuteru Shinozaki

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY 2011 ( 11 ) 1815 - 1823 2011.4

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

We investigated polymorphism in [Pt(fdpb) Cl] [Hfdpb = 1,3-bis(5-trifluoromethyl-2-pyridyl)benzene]. The following polymorphs of the complex were crystallized: yellow [Form Y; orthorhombic, Pca2(1), a = 23.4336(14) angstrom, b = 4.6377(2) angstrom, c = 15.7845(9) angstrom, Z = 4], red [Form R; monoclinic, C2/c, a = 21.3619(12) angstrom, b = 13.5629(7) angstrom, c = 13.6974(6) angstrom, beta = 122.301(2)degrees, Z = 8], and dark green [Form G; monoclinic, P2(1)/a, a = 6.7953(4) angstrom, b = 18.2519(12) angstrom, c = 13.5199(8) angstrom, beta = 96.039(2)degrees, Z = 4]. The yellow color of Form Y was due to the influence of stacking on the pi,pi* absorption of the Pt molecule; the red color of Form R originated from a MMLCT absorption due to Pt-Pt interactions in a closely stacked dimer; and the dark green of Form G was attributed to the absorption of a linear array of Pt-II complexes. The polymorphs emitted luminescence at around 550 (Form Y), 670 (Form R), and 750 nm (Form G). Mechanical grinding of the crystals changed the polymorphs from the crystalline to the amorphous phase; the emission spectra of ground samples of Forms Y and R, observed at 750 nm, were identical. When the amorphous solid was heated to around 500 K, the emission spectrum was blueshifted to 670 nm due to a phase transition from amorphous to crystalline. Heating also caused a crystal-crystal transformation; phase transitions from Form G to Form R and Form R to Form Y proceeded at 430-470 and 540-560 K, respectively.

DOI： 10.1002/ejic.201001359

A single tripodal ligand stabilizing three different oxidation states (II, III, and IV) of manganese

Yukinari Sunatsuki, Yukana Kishima, Tamami Kobayashi, Tomoka Yamaguchi, Takayoshi Suzuki, Masaaki Kojima, J. Krzystek, Markku R. Sundberg

CHEMICAL COMMUNICATIONS 47 ( 32 ) 9149 - 9151 2011

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

A series of mononuclear Mn-II, Mn-III, and Mn-IV complexes was prepared using a single tripodal ligand (H3L). Addition of a cation (NH4+, K+, Na+) to [(MnL)-L-III] showed a pronounced effect on the redox potentials. Different variants of Jahn-Teller distortion, axial elongation and compression, were observed in the Mn-III complexes.

DOI： 10.1039/c1cc12418h

Syntheses and crystal structures of mononuclear and dinuclear (pentamethylcyclopentadienyl)iridium(III) complexes containing 2-mercaptobenzimidazole

Mai Kotera, Takayoshi Suzuki

INORGANICA CHIMICA ACTA 363 ( 13 ) 3602 - 3605 2010.10

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

A reaction of [Cp*IrCl(2)](2) {Cp* = eta(5)-C(5)(CH(3))(5)}and 2-mercaptobenzimidazole (H(2)bimt) in methanol in a 1:2 molar ratio gave a yellow complex of [Cp*IrCl(2)(H(2)bimt)]center dot CH(3)OH (1). In compound 1 the H(2)bimt acts as a monodentately S-donating (kappa S) ligand. A similar reaction of [Cp*IrCl(2)](2) and H(2)bimt in the presence of NaOCH(3) (molar ratio of 1:2:2) gave an orange product (2) on addition of excess amount of NH(4)PF(6). Compound 2 was composed of an unsymmetrical dinuclear complex cation, [(Cp*IrCl)(2)(mu-Hbimt)(mu-H(2)bimt)](+), a PF(6) anion, and water molecules of crystallization. In the complex cation, H(2)bimt bridges two Ir(III) centers by S atom in the mu-kappa S:kappa S mode, while the monodeprotonated Hbimt ligand bridges via S and N atoms in the mu-kappa S:kappa N(1) mode. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ica.2010.05.053

Structures and spin states of mono- and dinuclear iron(II) complexes of imidazole-4-carbaldehyde azine and its derivatives

Yukinari Sunatsuki, Ryohei Kawamoto, Kunihiro Fujita, Hisashi Maruyama, Takayoshi Suzuki, Hiroyuki Ishida, Masaaki Kojima, Seiichiro Iijima, Naohide Matsumoto

COORDINATION CHEMISTRY REVIEWS 254 ( 15-16 ) 1871 - 1881 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

Mononuclear [Fe(H(2)L(R))(2)]X(2) (R = H, 2-Me, 5-Me, 2-Et-5-Me; X = ClO(4), BF(4)) and dinuclear [Fe(2)(H(2)L(R))(3)]X(4) complexes containing imidazole-4-carbaldehyde azine (H2LH) and its derivatives prepared by condensation of 4-formylimidazole, 2-methyl- or 5-methyl-4-formylimidazole, or 2-ethy1-4-methy15-formylimidazole, with hydrazine in a 2:1 mole ratio in methanol, were prepared and their magnetostructural relationships were studied. In the mononuclear complexes, H(2)L(R) acts as an unsymmetrical tridentate ligand with two imidazole nitrogen atoms and one azine nitrogen atom, while in the dinuclear complexes, H(2)L(R) acts as a dinucleating ligand employing four nitrogen atoms to form a triple helicate structure. At room temperature, [Fe(2)(H(2)L(H))(3)](ClO(4))(4) and [Fe(2)(H(2)L(2)-me)(3)](ClO(4))(4) were in the high-spin (HS) and low-spin (LS) states, respectively. The results are in accordance with the ligand field strength of H(2)L(2-Me) with electron-donating methyl groups being stronger than H(2)L(H), with the order of the ligand field strengths being H(2)L(2-me) > H(2)L(H). However, in the mononuclear [Fe(H(2)L(H))(2)](ClO(4))(2) and [Fe(H(2)L(2-Me))(2)](ClO(4))(2) complexes, a different order of ligand field strengths, H(2)L(H) > H(2)L(2-Me), was observed because [Fe(H(2)O)(2)](ClO(4))(2) was in the LS state while Fe(H(2)L(2-me))(2)](ClO(4))(2) was in the HS state at room temperature. X-ray structural studies revealed that the interligand steric repulsion between a methyl group of an H(2)L(2-Me) ligand and the other ligand in Fe(H(2)L(2-Me))(2)](ClO(4))(2) is responsible for the observed change in the spin state. The same is true for [Fe(H(2)L(2-Et-5-Me))2](ClO(4))(2), while [Fe(H(2)L(5-Me))2](ClO(4))(2) does not involve such a steric congestion and stays in the LS state over the temperature range 5-300K. Two kinds of crystals (polymorphs) were isolated for [Fe(2)(H(2)L(H))(3)](BF(4))(4) and [Fe(2)(H(2)L(2-Et-5-Me))(3)](ClO(4))(4), and they exhibited different magnetic behaviors. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ccr.2009.11.016

N,N '-Bis(3-nitrobenzylidene)-2,2 '-[2-(3-nitrophenyl)imidazolidine-1,3-diyl]diethanamine

Mohammad Hossein Habibi, Narges Abarghooei-Shirazi, Yuki Yamane, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 66 ( 3 ) O501 - U3985 2010.3

Language：English Publishing type：Research paper (scientific journal) Publisher：INT UNION CRYSTALLOGRAPHY

The title compound, C27H27N7O6, a Schiff base, was synthesized by the reaction of triethylenetetramine with 3-nitrobenzealdehyde. There are two independent molecules in the asymmetric unit. The central aromatic ring in one molecule makes dihedral angles of 23.99 (7) and 20.06 (6)degrees with the two terminal rings; for the second molecule, these angles are 26.14 (6) and 24.64 (6)degrees.

DOI： 10.1107/S1600536810003168

Novel Counter Anion Effects of Added [Co(NH3)(6)]X-3 (X- = Cl-, Br-, I-, or ClO4-) on Surface Tension Reduction in Aqueous Solutions of Anionic Surfactants

Sieng Sovanna, Takayoshi Suzuki, Masaaki Kojima, Satoshi Tachiyashiki, Masakazu Kita

CHEMISTRY LETTERS 39 ( 3 ) 306 - 307 2010.3

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Surface tension of anionic surfactant solutions, sodium dodecyl sulfate (SDS) or sodium dodecylbenzenesulfonate (SBS) decreases remarkably in the presence of [Co(NH3)(6)]X-3 (2.50 mM) (X- = Cl-, Br-, I-, or ClO4-) at 298 K, depending on the kind of counter anion X. The magnitude of reduction is in the order ClO4- > I- > Br- > Cl- for SDS solutions and ClO4- > Cl- > Br- > I- for SBS solutions at 0.03 mM surfactant concentrations.

DOI： 10.1246/cl.2010.306

Luminescence Change by the Solvent of Crystallization, Solvent Reorganization, and Vapochromism of Neutral Dicyanoruthenium(II) Complex in the Solid State

Taichi Abe, Takayoshi Suzuki, Kazuteru Shinozaki

INORGANIC CHEMISTRY 49 ( 4 ) 1794 - 1800 2010.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

The "solvent effect" on the solid-state luminescence of a neutral complex, [Ru(dbb)(2)(CN)(2)] (dbb = 4,4'-di-tert-butyl-2,2'-bipyridine), was presented. The crystals of this complex showed a variety of luminescence color from orange to dark-red, depending on the acceptor number of the solvent included in the crystal as a solvent of crystallization. The luminescence change was very similar to the solvatochromism in solution, which was attributed to the local donor-acceptor interaction between the CN group and the solvent molecules. The dynamic shift observed in the transient emission spectrum of the crystalline powder was accounted for by the solvent molecule reorganization. X-ray crystallography of [Ru(dbb)(2)(CN)(2)]center dot 3(CH3)(2)CO showed the complex molecule having an approximate C-2 symmetry and very weak interactions between the acetone molecules and the CN groups. A three-dimensional network constructed by acetone molecules was observed in the hydrophobic space consisting of t-butyl groups in dbb ligands. A thin film of the complex showed vapochromic behavior such that the luminescence changed depending on the solvent of crystallization. This suggests a capability for organic molecule discrimination using the complex in the solid state.

DOI： 10.1021/ic9021596

Preparation, Crystal Structures, and Spectroscopic and Redox Properties of Nickel(II) Complexes Containing Phosphane-(Amine or Quinoline)-Type Hybrid Ligands and a Nickel(I) Complex Bearing 8-(Diphenylphosphanyl)quinoline

Akira Hashimoto, Hiroshi Yamaguchi, Takayoshi Suzuki, Kazuo Kashiwabara, Masaaki Kojima, Hideo D. Takagi

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY 2010 ( 1 ) 39 - 47 2010.1

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Nickel(II) complexes containing P-N-type bidentate hybrid ligands of 2-aminoethylphosphanes (RR'Pea; RR' = Ph(2) or MePh) or 8-quinolylphosphanes (RR'Pqn), namely [Ni(P-N)(2)]-(BF(4))(2) [P-N = Ph(2)Pea (1), MePhPea (2), Ph(2)Pqn (3), or MePhPqn (4)] have been prepared, and their structural, spectroscopic, and electrochemical properties determined. The crystal structure analysis indicates that the 2-aminoethyl-phosphane complexes (1 and 2) have a square-planar coordination geometry around the Ni(II) center with a cis(PP) configuration, whereas the 8-quinolylphosphane complexes (3 and 4) exhibit a severe tetrahedral distortion because of the steric repulsion between the ortho-H atoms in the mutually cis-positioned quinolyl rings. Complexes I and 2 maintain their diamagnetic square-planar four-coordinate structure on acetonitrile solution, whereas complexes 3 and 4 show paramagnetic behavior. Spectroscopic and electrochemical measurements suggest that the ligand-field strengths of these four P-N-type ligands increase in the order Ph(2)Pqn (3) < MePhPqn (4) < Ph(2)Pea (1) < MePhPea (2). The Ph(2)Pqn complex 3 is readily reduced by Zn powder to afford the corresponding nickel(I) complex [Ni(Ph(2)Pqn)(2)]BF(4) (5). The crystal structure of complex 5 reveals that the Nil ion adopts a distorted tetrahedral coordination geometry with slightly longer (approximate to 0.05 angstrom) Ni-P and Ni-N bond lengths than those in the corresponding Ni(II) complex 3.

DOI： 10.1002/ejic.200900767

Homochiral column structure of rac- and Lambda-[M-III(tn)(3)]P3O9 (M = Co, Cr; tn=1,3-diaminopropane; P3O9 = cyclotriphosphate(3-)) produced by multiple hydrogen bonds

Yukinari Sunatsuki, Sho Miyahara, Takayoshi Suzuki, Masaaki Kojima, Toshio Nakashima, Naohide Matsumoto, Frode Galsbol

NEW JOURNAL OF CHEMISTRY 34 ( 12 ) 2777 - 2784 2010

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

The crystal structures of rac- and Lambda-[M-III(tn)(3)]P3O9 center dot nH(2)O (M = Co, Cr; tn = 1,3-diaminopropane = trimethylenediamine; P3O9 = cyclotriphosphate(3-))were determined by single-crystal X-ray analyses. In rac-[Co(tn)(3)]P3O9 center dot 7.3H(2)O, the [Co(tn)(3)](3+) cations with the same absolute configuration (Delta or Lambda) and the P3O93- anions are alternately arrayed and connected by multiple NH center dot center dot center dot O hydrogen bonds to form a homochiral columnar structure. Adjacent homochiral columns with opposite chirality are connected by intercolumn hydrogen bonds to form a racemic pair of columns. The crystal structure of rac-[Cr(tn)(3)]P3O9 center dot 7.5H(2)O is similar to that of the Co complex; however, there exist two types of racemic pairs of columns. In the crystal of Lambda-[Co(tn)(3)]P3O9 center dot 2.5H(2)O, a pair of columns consisting of alternately stacked Lambda-[Co(tn)(3)](3+) cations and P3O93- anions are linked by hydrogen bonds. Neighboring column pairs are further linked by hydrogen bonds to form a three-dimensional (3-D) sheet structure. The crystal structure of Lambda-[Cr(tn)(3)]P3O9 center dot 2.5H(2)O is isomorphous with the Co complex. The circular dichroism (CD) spectra of aqueous solutions of Lambda-[M(tn)(3)]Br-3 (M = Co, Cr) change when P3O93- is added, and the changes were explained by ion pair formation through hydrogen bonds.

DOI： 10.1039/c0nj00270d

Mononuclear Bis(tridentate)-Type and Dinuclear Triple Helicate Iron(II) Complexes Containing 2-Ethyl-5-methylimidazole-4-carbaldehyde Azine

Yukinari Sunatsuki, Hisashi Maruyama, Kunihiro Fujita, Takayoshi Suzuki, Masaaki Kojima, Naohide Matsumoto

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 82 ( 12 ) 1497 - 1505 2009.12

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

Mononuclear [Fe(H2L2-Et-5-Me)(2)](2+) and dinuclear [Fe-2(H2L2-Et-5-Me)(3)](4+) complexes, where H2L2-Et-5-Me denotes 2-ethyl-5-methylimidazole-4-carbaldehyde azine, were prepared and isolated as the perchlorate salts, and their structures and magnetic properties were studied. In file mononuclear complex, the ligand acts as ail unsymmetrical tridentate ligand with two imidazole nitrogen atoms and one azine nitrogen atom. The complex was in the HS state above 50 K. In the dinuclear complex, each ligand acts as a dinucleating ligand employing four nitrogen atoms to form a triple helicate structure. Two types of crystals, plates and blocks, were isolated for the dinuclear complex. The plate crystals exhibited a sharp spin transition, [LS-HS] <-> [HS-HS], with no [LS-LS] state being observed. The block crystals remained in the [HS-HS] state above 50 K.

DOI： 10.1246/bcsj.82.1497

Bis[mu-2-(aminosulfanyl)pyridine(1-)]bis[(eta(5)-pentamethylcyclopentadienyl)iridium(III)] diiodide

Yusuke Sekioka, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 65 ( 10 ) M1229 - + 2009.10

Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

In the title dinuclear iridium(III) complex, [Ir-2(C10H15)(2)-(C5H5N2S)(2)]I-2, the iridium(III) atoms are bridged by 2-(aminosulfanyl) pyridine(1-) [(2-py)SNH] ligands in a mu-(2-py) SNH-kappa N-2(py),N(NH):kappa N(NH) mode. The dinuclear complex cation lies on a crystallographic inversion center, resulting in a planar Ir2N2 ring with an Ir-N(py) bond length of 2.085 (9) angstrom and bridging Ir-N(NH) bonds of 2.110 (9) and 2.113 (9) angstrom. The two (2-py) S units have mutually anti configurations with respect to the Ir2N2 ring

DOI： 10.1107/S1600536809037167

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