Faculty Profiles - SUZUKI Takayoshi

Papers - SUZUKI Takayoshi

Division display 81 - 100 of about 189 ／ All the affair displays >>

Structures and Spin States of Bis(tridentate)-Type Mononuclear and Triple Helicate Dinuclear lron(II) Complexes of Imidazole-4-carbaldehyde azine

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

INORGANIC CHEMISTRY 48 ( 18 ) 8784 - 8795 2009.9

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

Mononuclear [Fe(H(2)L(R))(2)](2+) and dinuclear [Fe(H(2)L(R))(3)](4+) (R = H, 2-Me, 5-Me) complexes containing the new imidazole-4-carbaldehyde azine ligand (H(2)L(H)) and its derivatives (H(2)L(2-Me) and H(2)L(5-Me)) prepared from the condensation reaction of 4-formylimidazole or 2-methyl- or 5-methyl-4-formylimidazole with hydrazine (2:1) 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. At room temperature, [Fe(2)(H(2)L(H))(3)](CIO(4))(4) and [Fe(2)(H(2)L(2-Me))(3)](CIO(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-M) (e)> H(2)L(H), However, in the mononuclearjFe(H(2)L(H))(2)](CIO(4))(2) and [Fe(H(2)L(2-Me))(2)](CIO(4))(2) complexes, a different order of Iigand field strengths, H(2)L(H) > H(2)L(2-Me), was observed because [Fe(H(2)L(H))(2)] (CIO(4))(2) was in the LS state while [Fe(H(2)L(2-Me))(2)](CIO(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)](CIO(4))(2) is responsible for the observed change in the spin state. Two kinds of crystals, needles and blocks, were isolated for [Fe2(H(2)L(H))(3)](BF(4))(4), and both exhibited a sharp spin transition, [LS-HS] <-> [HS-HS], The spin transition of the block crystals is more abrupt with a hysteresis, T(c)up arrow = 190 K and T(c)down arrow = 183 K with Delta T= 7 K.

DOI： 10.1021/ic900977m

Bis{mu-4,4 '-dimethoxy-2,2 '-[propane-1,2-diylbis(nitrilomethylidyne)]diphenolato}bis({4,4 '-dimethoxy-2,2 '-[propane-1,2-diylbis(nitrilomethylidyne)]diphenol}manganese(III)) bis(hexafluoridophosphate)

Mohammad Hossein Habibi, Elham Askari, Reza Mokhtari, Morteza Montazerozohori, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 65 ( 8 ) M1004 - U1656 2009.8

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

In the title complex, [Mn-2(C19H2ON2O4)(2)(C19H22N2O4)(2)](PF6)(2), the Mn-III ion is coordinated by two O [Mn-O = 1.855 (2) and 1.887 (2) angstrom] and two N [Mn-N = 1.982 (3) and 1.977 (3) angstrom] atoms from the tetradentate Schiff base ligand and a coordinated axial ligand [Mn-O = 2.129 (2) angstrom]. The centrosymmetric dimer contains two Jahn-Teller-distorted Mn-III ions, each in a nearly octahedral geometry, connected through two phenolate bridges from two ligands. There are two stereogenic centers. The methyl group and the H atom attached to the middle propane C atom are disordered over two positions with occupancy factors in the ratio 0.58:0.42. The crystal is therefore a mixture of two diasteroisomers, viz. RS/SR and RR/SS. In the axial ligand, the two benzene rings form a dihedral angle of 56.97 (5)degrees and the dihedral angle between the two MnNC3O chelate rings is 2.98 (12)degrees

DOI： 10.1107/S1600536809028591

2,2 '-[(E,E)-1,1 '-(2,2-Dimethylpropane-1,3-diyldinitrilo)diethylidyne]diphenol

Morteza Montazerozohori, Mohammad Hossein Habibi, Ahmad Hojjati, Reza Mokhtari, Yuki Yamane, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 65 ( 7 ) 01662 - U3191 2009.7

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

The title Schiff base, C(21)H(26)N(2)O(2), contains two intramolecular O-H center dot center dot center dot N hydrogen bonds between the hydroxyl groups and the nearest imine N atoms, each leading to a six-membered ring. Weak C-H center dot center dot center dot O hydrogen bonds result in a ladder network running along the a axis. In addition, intermolecular C-H center dot center dot center dot pi interactions serve to stabilize the extended structure.

DOI： 10.1107/S1600536809022855

Crystal structures of (azido)(pentamethylcyclopentadienyl)iridium(III) complexes containing various types of bidentate ligands

Takayoshi Suzuki, Mai Kotera, Asuka Takayama, Masaaki Kojima

POLYHEDRON 28 ( 11 ) 2287 - 2293 2009.7

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

Several (azido)iridium(III) complexes having a pentamethylcyclopentadienyl (Cp*) group, [Cp*Ir(N(3))(2)(Ph(2)Ppy-kappa P)] (1: Ph(2)Ppy = 2- diphenylphosphinopyridine), (Cp*Ir(N(3))(Ph(2)Ppy-kappa P,kappa N)]CF(3)SO(3) (2), [Cp*Ir(N(3))(dmpm)]PF(6) (3: dmpm = bis(dimethylphosphino)methane), [Cp*Ir(N(3))(Ph(2)Pqn)]PF(6)center dot CH(3)OH (4 center dot CH(3)OH: Ph(2)Pqn = 8- diphenylphosphinoquinoline), and [Cp*Ir(N(3))(pybim)] (5: Hpybim = 2-(2- pyridyl)benzimidazole) have been prepared and their crystal structures have been analyzed by X-ray diffraction. In complex 1, the Ph(2)Ppy ligand is only coordinated via the P atom (-kappa P), while in 2 it acts as a bidentate ligand through the P and N atoms (-kappa P,kappa N) to form a four-membered chelate ring. Comparing the structural parameters of the chelate ring in 2 with those of a similar five-membered chelate ring formed by ph(2)Pqn in 4, it became apparent that the angular distortion in the Ph(2)Ppy-kappa P,kappa N ring was remarkable, although the Ir-P and Ir-N bonds in the Ph(2)Pqn-kappa P,kappa N ring were not elongated very much from the corresponding bonds in the Ph(2)Pqn-kappa P,kappa N ring. In the pybim complex 5, the five-membered chelate ring was coplanar with the pyridine and benzimidazolyl rings. With the related (azido)iridium(III) complexes analyzed previously, comparison of the structural parameters of the Ir-N(3) moiety in (Cp*Ir(III)(N(3))(L-L')(+/0) complexes reveals all anomalous feature of the 2,2'-bipyridyl (bpy) complex, [Cp*Ir(N(3))(bpy)]PF(6). (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.poly.2009.04.010

{4,4 '-Dimethoxy-2,2 '-[2,2-dimethylpropane-1,3-diylbis(nitrilomethylidyne)]diphenolato}nickel(II)

Morteza Montazerozohori, Mohammad Hossein Habibi, Reza Mokhtari, Yuki Yamane, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 65 ( 7 ) M703 - U170 2009.7

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

In the title complex, [Ni(C(21)H(24)N(2)O(4))], the Ni(II) ion has a slightly distorted square-planar geometry, coordinated by the two N and two O atoms of a new tetradentate Schiff base ligand. The dihedral angle between the planes of the two NiNC(3)O chelate rings is 14.37 (12)degrees.

DOI： 10.1107/S1600536809019965

{N,N '-Bis[(E)-3-phenylprop-2-en-1-ylidene]propane-1,3-diamine-kappa N-2,N ']dichloridocobalt(II)

Morteza Montazerozohori, Mohammad Hossein Habibi, Mehdi Amirnasr, Keita Ariyoshi, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 65 ( 6 ) M617 - U222 2009.6

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

The Co-II atom in the title monomeric Schiff base complex, [CoCl2(C21H22N2)], is bonded to two Cl atoms and to two N atoms of the Schiff base ligand N,N '-bis[(E)-3-phenylprop-2-en-1-ylidene]propane-1,3-diamine in a distorted tetrahedral geometry. The molecule has an idealised mirror symmetry, but is not located on a crystallographic mirror plane.

DOI： 10.1107/S1600536809016274

Surface tension reduction (STR) in aqueous solutions of anionic surfactants with cobalt(III) complexes

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

JOURNAL OF COLLOID AND INTERFACE SCIENCE 332 ( 1 ) 194 - 200 2009.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

It has been observed that, at 25.0 +/- 0.1 degrees C, [Co(NH(3))(6)](ClO(4))(3), [Co(en)(3)](ClO(4))(3), [Co(bpy)(3)](ClO(4))(3), and [Co(phen)(3)](ClO(4))(3) in the regions of 1.25-5.00 mM aqueous solutions cause a significant surface tension reduction (STR) of water by the surfactants, sodium dodecylsulfate (SIDS) and sodium dodecylbenzenesulfonate (SBS), suggesting the formation of the 1:1 and 1:2 association complexes, {[complex](3+)(S(-))}(2+) and {[complex](3+)(S(-))(2)}(+) where [complex](3+) =[Co(NH(3))(6)](3+), [Co(en)(3)](3+), [Co(bpy)(3)](3+), or [Co(phen)(3)](3+), S(-) = DS(-) or BS(-). The effect of [Co(en)(3)](3+) on STR in SDS-water system is the largest due to a strong hydrophilic interaction between amino protons of [Co(en)(3)](3+) and sulfate oxygen atoms of DS(-). The effects of [Co(en)(3)](3+), [Co(bpy)(3)](3+), and [Co(phen)(3)](3+) on STR in SBS-water system are significant and almost same, meaning that the hydrophilic interaction between [Co(en)(3)](3+) and the sulfonate group is comparable to the hydrophobic interaction between [Co(bpy)(3)](3+) or [Co(phen)(3)](3+) and the phenyl group of BS(-). The Co(III) complexes of 1.25-5.00 mM are precipitated as {[complex](3+)(S(-))(3)} at 0.0295-0.173 mM of S(-). The precipitates, {[Co(bpy)(3)](3+)(S(-))(3)} and {[Co(phen)(3)](3+)(S(-))(3)} can be dissolved at higher molar ratio of [S(-)]/[complex(3+)] than 3.5 for SDS and 4.0 for SBS. This observation suggests that the aggregated premicelle [Co(bpy or phen)(3)](2)(DS)(7)(-) or aggregated premicelle [Co(bpy or phen)(3)](BS)(4)(-) is formed. (C) 2008 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2008.12.005

Remarkable chiral and luminescent properties of novel Yb(III) and Eu(III) complexes containing BINAPO ligand

Md. Abdus Subhan, Yasuchika Hasegawa, Takayoshi Suzuki, Sumio Kaizaki, Yanagida Shozo

INORGANICA CHIMICA ACTA 362 ( 1 ) 136 - 142 2009.1

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

Lanthanide complexes are of great importance for their prospective applications in wide range of science and technology. Chiral lanthanide complexes can constitute stereo-discriminating probes in biological media, owing to the luminescent properties of the rare-earth ions. Sensitized emission with narrow bandwidth, having fast radiation rate and high emission quantum efficiency are the main perspective for synthesizing the complexes. Attention has been given on remarkable chirality with high dissymmetry factors (g = Delta epsilon(ext)/epsilon(max)) of the complexes. For this purpose, beta-diketonato ligands with chiral BINAPO (1,1'-binapthyl phosphine oxide) ligand were chosen to achieve the goal. The complexes [Ln(TFN)(3)-(S-BINAPO)](TFN = 4,4,4- trifluoro-1(2-napthyl)-1,3-butanedione), [Ln(HFT)(3)(S-BINAPO)] (HFT = 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)-1,3-hexanedione) and [Ln(HFA)(3)(S-BINAPO)](hfa = hexafluoroacetylacetonate) (where Ln = Yb, Eu) were synthesized. The complex, [Eu(TFN)(3)(S-BINAPO)] gives strong red emission at 615 nm with narrow emission band (< 10 nm) when excited by 465 nm light with quantum efficiency 86%. The dissymmetry factors (g = Delta epsilon(ext)/epsilon(max)) corresponding to the F-7(1) -> D-5(0) transition at 590 nm is 0.091 for [Eu(TFN)(3)(S-BINAPO)] and for [Yb(hfa)(3)(S-BINAPO)](hfa = hexafluoroacetylacetonate) corresponding to the F-2(7/2) -> F-2(5/2) transitions is 0.12, are among the largest values for both Eu and Yb complexes to date, respectively. The Eu complexes, [Eu(HFT)(3)(S-BINAPO)] and [Eu(TFN)(3)(S-BINAPO)] are found to be spontaneously emissive, showing bright red emission, when placed in sunlight or even in the laboratory when light is switched on. (c) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ica.2008.03.093

Synthesis, structure, and electrochemistry of trans-[Co(III){(BA)(2)pn)(L)(2)]ClO(4) complexes

Soraia Meghdadi, Mehdi Amirnasr, Mohammad H. Habibi, Ahmad Amiri, Fatemeh Ahmadi, Keiko Kihara, Takayoshi Suzuki, Hamid Reza Bijanzadeh

TRANSITION METAL CHEMISTRY 33 ( 7 ) 879 - 886 2008.10

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

The structure, spectroscopic, and electrochemical properties of [Co{(BA)(2)pn}(L)(2)]ClO(4) complexes, where (BA)(2)pn = N,N '-bis(benzoylacetone)-1,3-propylenediimine dianion and the two ancillary ligands (L) are pyridine, py (1), and 4-methylpyridine, 4-Mepy (2), have been investigated. These complexes have been characterized by elemental analyses, IR, UV-Vis and (1)H-NMR spectroscopy. The crystal structure of [Co{(BA)(2)pn}(py)(2)]ClO(4) (1) has been determined by X-ray diffraction. The coordination geometry around cobalt(III) is best described as a distorted octahedron. The electrochemical reduction of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Co(III)-Co(II) is electrochemically irreversible, which is accompanied by the dissociation of the axial N(py)-cobalt bonds. This process becomes quasi-reversible upon the addition of excess py ligands. The second reduction step of Co(II/I) shows reversible behavior and is not influenced by the nature of the axial ligands.

DOI： 10.1007/s11243-008-9127-2

Structural versatility of 5-methyltetrazolato complexes of (eta(5)-pentamethylcyclopentadienyl)iridium(III) incorporating 2,2 '-bipyridine, N,N-dimethyldithiocarbamate, or 2-pyridinethiolate ligands

Mai Kotera, Yusuke Sekioka, Takayoshi Suzuki

INORGANIC CHEMISTRY 47 ( 9 ) 3498 - 3508 2008.5

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

Several new mono- and dinuclear eta(5)-pentamethylcyclopentadienyl (Cp*) iridium(III) complexes bearing 5-methyltetrazolate (MeCN4-) have been synthesized and their molecular and crystal structures have been determined. For complexes incorporating 2,2'-bipyridine (bpy) or 1,10-phenanthroline (phen), both mononuclear kappa N-2-coordinated and dinuclear mu-kappa N-1:kappa N-3-bridging MeCN4 Complexes were obtained: [Cp*Ir(bpy or phen)(MeCN4-kappa N-2)]PF6 (1 or 3) and [{Cp*Ir(bpy or phen)}(2)(mu-MeCN4-kappa N-1:kappa N-3)](PF6)(3) (2 or 4), respectively. It was confirmed by X-ray analysis that the dinuclear complex in 2 has a characteristic structure with a pyramidal pocket constructed from a mu-kappa N-1:kappa N-3-bridging MeCN4- and two bpy ligands. In the case of analogous complexes with N,N-dimethyldithiocarbamate (Me(2)dtc(-)), yellow platelet crystals of mononuclear kappa N-1-coordinated complex, [Cp*Ir(Me(2)dtc)(MeCN4-kappa N-1)]center dot HN4CMe (5 center dot HN4CMe), and yellow prismatic crystals of dinuclear mu-kappa N-1:kappa N-4-bridging one, [{Cp*Ir(Me(2)dtc)}(2)(mu-MeCN4-kappa N-1: kappa N-4)]PF6 (6), were deposited. The kappa N-1- and kappa N-1:kappa N-4-bonding modes of MeCN4- in these complexes presumably arise from the compactness of the Me(2)dtc(-) coligand. 6 is the first example in which tetrazolates act as a mu-kappa N-1: kappa N-4-bridging ligand. Furthermore, the molecular and crystal structures of dinuclear complexes having mu-kappa S-2,N:kappa S-bridging 2-pyridinethiolate (2-Spy(-)) or 8-quinolinethiolate (8-Sqn(-)) ligands have been determined: [(Cp*Ir)(2)(mu-2-Spy or 8-Sqn-kappa S-2,N:kappa S)(2)] (7 or 8). These thiolato-bridging complexes were stable toward the addition of 5-methyltetrazole (HN4CMe), owing to the characteristic intramolecular stacking interaction between the pyridine or the quinoline rings. The 2-Spy complex of 7, however, reacted with an excess amount of Na(N4CMe), resulting in cleavage of the Ir-N(py) bond and coordination of MeCN4- in the mu-kappa N-2:kappa N-3-bridging mode: [(Cp*Ir)(2)(mu-2-Spy-kappa S:kappa S)(2)(mu-MeCN4-kappa N-2:kappa N-3)]PF6 (9). This bridging mode of MeCN4- was also observed in the triply bridging MeCN4 complex: [(Cp*Ir)(2)(mu-MeCN4-kappa N-2:kappa N-3)(3)]PF6 (10). In these various MeCN4 complexes, the structural parameters of the MeCN4 moiety were not perturbed by the difference in the bonding modes.

DOI： 10.1021/ic701631k

Structural comparison of (pentamethylcyclopentadienyl) iridium(III) azido complexes containing potentially N,S-bidentate N-heterocyclic thiolates: 2-or 8-quinolinethiolate and benzimidazole-2-thiolate

Mai Kotera, Yusuke Sekioka, Takayoshi Suzuki

INORGANICA CHIMICA ACTA 361 ( 5 ) 1479 - 1484 2008.4

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

The crystal structures of mononuclear (azido)( pentamethylcyclopentadienyl) iridium(III) complexes bearing 2- or 8-quinolinethiolate (n-Sqn(-)), [Cp* Ir(N-3)( n-Sqn)] {n = 2 (1) or 8 ( 2); Cp* = eta(5)- C5Me5} have been determined by X-ray analysis. The 2-Sqn complex, 1, acquires severe steric strains in the four-membered kappa(2) N, S chelate ring, while the 8-Sqn isomer, 2, forms a strain-free five-membered planar kappa(2) N, S chelate ring. It has also been revealed that the corresponding benzimidazole-2-thiolate (Hbimt(-)) complex, which was obtained similarly to the above n-Sqn complexes from [Cp* Ir(N-3)(2)] (2) and Na(Hbimt), takes an unsymmetrical dinuclear structure bridged by two Hbimt(-) ligands with different bonding modes, [Cp* Ir(N-3){mu(S: N-1)-Hbimt}{mu(S:S)-Hbimt}Ir(N-3)Cp*] MeOH (3). (c) 2007 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.ica.2007.09.040

Crystal structure and chiroptical spectra of sodium tetrakis (+)-hfbc Pr(III) complex

Dai Shirotani, Takayoshi Suzuki, Kazuaki Yamanari, Sumio Kaizaki

JOURNAL OF ALLOYS AND COMPOUNDS 451 ( 1-2 ) 325 - 328 2008.2

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

The X-ray crystal structure of tetrakis (+)-hfbc Pr(III) complex, Na[Pr((+)-hfbc)(4)]center dot CH3CN, was compared with that of the corresponding Na-La complex with a pseudo-achiral dodecahedron, and the solution CD spectra were also discussed in the 4f-4f transition in consideration of the exciton CD couplet showing Delta-SAPR-8 configuration in CHCl3. (c) 2007 Published by Elsevier B.V.

DOI： 10.1016/j.jallcom.2007.04.236

[2,6-Bis(5-methyl-2-pyridyl)phenyl-kappa N-3,C-1,N ']chloridoplatinum(II)

Taichi Abe, Kazuteru Shinozaki, Noriaki Ikeda, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS 63 ( 10 ) M456 - M458 2007.10

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

In the title compound, [ Pt( C18H15N2) Cl], the Pt-II centre adopts a distorted square- planar coordination geometry due to the pincer- type monoanionic N - C - N tridentate ligand. The planar complexes stack via pi - pi interactions to form twodimensional accumulated sheets. This packing pattern is in contrast to that in related pincer- type N - C - N complexes, which exhibit a one- dimensional columnar stacking.

DOI： 10.1107/S0108270107044009

Azido{N,N '-bis[3-(2-nitrophenyl)prop-2-enylidene] ethylenediamine}(triphenylphosphine)copper(I) chloroform solvate

Mohammad Hossein Habibi, Arash Lalegani, Reza Mokhtari, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 63 ( 10 ) M2580 - U1316 2007.10

(Bromido)[N,N '-bis(2-nitrocinnamaldehyde)ethylenediamine](triphenylphosphine)copper(I)

Mohammad Hossein Habibi, Arash Lalegani, Reza Mokhtari, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 63 ( 10 ) M2479 - U421 2007.10

{N,N '-Bis[3-(2-nitrophenyl)prop-2-enylidene]ethylenediamine-kappa N-2,N '}iodido(triphenylphosphane-kappa P)copper(I)

Mohammad Hossein Habibi, Arash Lalegani, Reza Mokhtari, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE 63 ( 10 ) M2472 - U346 2007.10

Magnetic interactions in a series of paramagnetic Ln(III) complexes with a chelated imino nitroxide radical

Toshiaki Tsukuda, Takayoshi Suzuki, Sumio Kalzaki

POLYHEDRON 26 ( 13 ) 3175 - 3181 2007.8

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

The magnetic interactions in a new series of isostructural imino nitroxide radical lanthanide(III) complexes, [Ln(hfac)(3)(IM2py)] (Ln = Gd-Yb: IM2py = 2-(2'-pyridyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazoline-l-oxy; hfac = 1, 1, 1, 5,5,5-hexafluoro-2,4-pentanedione), are examined by considering the intrinsic paramagnetic contribution of the Ln(III) ion from the corresponding [Ln(hfaC)3(pybzim)] with a diamagnetic pybzim(2-(2-pyridyl)benzimidazole) ligand; the Ln(III)-IM2py interaction being antiferromagnetic for the 4f(7) to 413 Ln(III) complexes and negligibly small for the other complexes. This series is the first example reverse to the previous cases for the series of Ln-Cu or Ln-aminoxyl(NIT) radical (4,5-dihydro-4,4,5,5-tetramethyl-IH-imidazoline-3-oxide-l-oxy) complexes, other than only a few examples of semiquinone Ln complexes. This reverse nature of the magnetic interaction, as compared with the NIT complexes, validates the empirical approach by O. Kahn et al. [Inorg. Chem. 38 (1999) 3692; J. Am. Chem. Soc. 122 (2000) 3413] in the spin-coupled systems for a series of Ln(III) complexes. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.poly.2007.02.024

Dibromido(eta(5)-pentamethylcyclopenta-dienyl)(5-phenyldibenzophosphole-kappa P)-iridium(III) dichloromethane solvate

Mai Kotera, Takayoshi Suzuki

ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS 63 ( 7 ) M1818 - U463 2007.7

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

The title compound, [IrBr2(eta(5)-C10H15)(C18H13P)]center dot CH2Cl2, is the first example of an iridium(III) phosphole complex to be characterized by X-ray crystallographic analysis. The Ir-P bond length is 2.2828 (15) angstrom, which is shorter by 0.04 angstrom than that of the analogous PPh3 complex. This is indicative of the steric compactness of 5-phenyldibenzophosphole compared with PPh3. The dibenzophosphole portion of the ligand is nearly planar, and the planes of the dibenzophosphole units of neighbouring molecules are stacked on top of each other to form a dimer in the crystal structure. The closest C center dot center dot center dot C distances between the planes are similar to 3.9 angstrom.

DOI： 10.1107/S1600536807026621

Synthesis and magneto-optical properties of a series of bis(beta-diketonato) Co(II) complexes with imino nitroxide radical chelate

Terukazu Ishida, Kelichi Adachi, Satoshi Kawata, Takayoshi Suzuki, Akira Fuyuhiro, Sumio Kaizaki

POLYHEDRON 26 ( 9-11 ) 2013 - 2020 2007.6

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

A series of bis(4,4,4-trifluoro-1-R-1,3-butanedinato) Co(II) complexes with imino nitroxide radical(IM2py), [Co(RtfC)(2)(IM(2)py)] (R = trifluoromethyl, phenyl, naphthyl, thienyl), was prepared and characterized by the X-ray analysis which demonstrated the stereo-specific formation of the trans(CF3)-isomer with the trans disposition of the CF3 groups. The significant substituents effect on the UV-Vis spectra and magnetic properties were discussed in consideration of the inversion of the d pi(t(2g)) orbital levels leading to the orbital orthogonality or overlap with the SOMO pi* of IM2py in terms of the AOM parametrizations or spin-paring energy. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.poly.2006.09.054

Preparation and characterization of mixed-ligand cobalt(III) complexes containing (3-aminopropyl) dimethylphosphine (pdmp). Conformation of the six-membered pdmp chelate ring

Takayoshi Suzuki, Katsuhiro Fujiiwara, Hideo D. Takagi, Kazuo Kashiwabara

DALTON TRANSACTIONS 2007 ( 3 ) 308 - 319 2007

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

Several new cobalt(III) complexes containing (3-aminopropyl) dimethylphosphine (pdmp) have been prepared, and their molecular structures have been determined. A dichloro complex of trans(Cl,Cl)-cis(P,P)-[CoCl2(pdmp)(2)]PF6 (1) was prepared from trans-[CoCl2(py)(4)]Cl center dot 6H(2)O and pdmp. X-Ray crystallography confirmed the (C-2)-chair(2) conformation of two six-membered pdmp chelate rings in 1, while the analogous 1,3-bis(dimethylphosphino) propane (dmpp) complex trans-[CoCl2(dmpp)(2)]ClO4 (3) exhibited the (D-2d)-twist(2) conformation. Substitution reactions of 1 for ethane-1,2-diamine (en), pentane-2,4-dionate (acac), and N,N-dimethyldithiocarbamate (dtc) gave the mixed-ligand tris(chelate)-type complexes of [Co(en)(2)(pdmp)]Cl-2(PF6) (5), [Co(acac)(pdmp)(2)](PF6)(2) (7), and [Co(dtc)(3-n)(pdmp)(n)](PF6)(n) [n = 1 (9) or 2 (10)], respectively. The conformer of the complex cation in 5 was assigned as lel center dot ob center dot chair by X-ray analysis. In the case of the acac complex 7, both trans(P,N) (7a) and trans(N,N) (7b) isomers were isolated, and the complex cations were characterized as syn-chair(2) and anti-chair(2) conformers, respectively, with respect to the six-membered pdmp chelate rings. These conformers coincide with the most stable ones anticipated by the DFT optimum geometry calculations. In the crystal structure of trans(P,N)-[Co(dtc)(pdmp)(2)](BPh4)(2) (10') one of the pdmp chelate rings adopted a skew-boat (twist) conformation, which reduced the intramolecular steric ring-ring interaction effectively. The DFT optimized geometries for several isomers and/or conformers of [CoCl2(pdmp)(2)](+) were compared.

DOI： 10.1039/b612025c

　 PREV - NEXT 　

1
2
3
4
5
6
7
8
9
10