※一部利用できない機能があります
| 1.
論文 |
論文
|
Ihara, Yoshinori ; Satake, Yasuhiro ; Suzuki, Masatatsu ; Uehara, Akira
概要:
The thermochemical changes in coordination structure of diaquabis(N,N- or N,N′,-dialkylethylenediamine)nickel(II) comple
…
xes ([Ni(H2O)2(diamine)2]X2·nH2O) were reinvestigated by means of TG-DTA and electronic spectroscopy at room and elevated temperatures, where diamine is N,N (or N,N′-dimethylethylenediamine (NN- or NN′-dmen) or N,N-(or N,N′)-diethylethylenediamine (NN- or NN′-deen); X is Cl−, Br−, I−, or NO3−; n is 0, 1, 2, or 3. The diaqua complexes prepared were all trans except for cis-[Ni(H2O)2(NN-dmen)2]I2. The trans complexes with the symmetric (N,N′-dialkylsubstituted) diamines brought about a deaquation-anation upon heating, retaining the original trans configuration, while those with the asymmetric (N,N-dialkylsubstituted) diamines transformed into the cis complexes. In the case of the NN-dmen complexes, cis-halogenoaqua species were isolated as a stable intermediate during the thermal reactions. The complex nitrates changed to trans-dinitrato or cis-mononitrato species depending upon the diamines. The effects of the N-substituents in the diamines and of the anions on the patterns of thermal reactions were also discussed.
続きを見る
|
||||
| 2.
論文 |
論文
|
Ihara, Yoshinori ; Satake, Yasuhiro ; Fujimoto, Yumi ; Senda, Hitoshi ; Suzuki, Masatatsu ; Uehara, Akira
概要:
The structures of two diaquabis(N,N-dialkylethylenediamine)nickel(II) chlorides ([Ni(H2O)2(diamine)2]Cl2·nH2O) were dete
…
rmined by X-ray crystallographic studies, where diamine is N,N-dimethylethylenediamine(NN-dmen) or N,N-diethylethylenediamine (NN-deen). Both complexes are trans and crystallize in the monoclinic space group P21⁄n. The unit cell parameters of the NN-dmen complex, NiCl2C8N4O2H32, are a=7.531(1), b=13.092(1), c=9.591 Å, β=107.76(1)°, and Z=2, and those of the NN-deen complex, NiCl2C12N4O2H36, are a=9.154(1), b=8.692(1), c=12.395(2) Å, β=104.46(1)°, and Z=2. In trans-[Ni(H2O)2(NN-dmen)2]Cl2·2H2O and trans-[Ni(H2O)2(NN-deen)2]Cl2, the Ni–NMe2 and Ni–NEt2 bond distances (2.183 and 2.271 Å) are much longer than the Ni–NH2 distances (2.078 and 2.064 Å), forming tetragonally distorted octahedrons with four close in-plane neighbors(N2O2) and two remote axial ones(N2). It is apparent that this distortion originates from the steric requirement of N-substituted groups. Such a distortion significantly affects the electronic spectra of these complexes.
続きを見る
|
||||
| 3.
論文 |
論文
|
Osawa, Kunitoyo ; Furutachi, Hideki ; Fujinami, Shuhei ; Suzuki, Masatatsu
概要:
金沢大学理学部<br />金沢大学大学院自然科学研究科物質創成<br />The title complex, trans,trans,trans-[FeII(C10H 6NO2)2-(C2H6O) 2], is centrosymmetr
…
ic and the quinaldinate ligands form five-membered chelate rings. The geometry of the complex is distorted octahedral, with a trans-FeN2O4 chromophore. The hydroxy H atom forms an intermolecular hydrogen bond with the carbonyl O atom of the quinaldinate ligand. © 2003 International Union of Crystallography Printed in Great Britain - all rights reserved.
続きを見る
|
||||
| 4.
論文 |
論文
|
Suzuki, Masatatsu ; Uehara, Akira
概要:
Reaction of copper(II) ion with hexacyanoferrate(II) ion, [Fe(CN)6]4−, in an aqueous solution containing such an amine a
…
s en (1,2-ethanediamine), tn (1,3-propanediamine), dien (bis(2-aminoethyl)amine), or dpt (bis(3-aminopropyl)amine), gave two types of complexes: Double complex salts, [Cu(en or tn)2]2[Fe(CN)6]·nH2O(n=5–8), and cyanide-bridged complexes, [(Cu(dien or dpt))2(NC)2Fe(CN)4]·4H2O. The infrared spectra of the complexes in the νCN region revealed that the complexes, [(Cu(dien or dpt))2(NC)2Fe(CN)4]·4H2O, contain cyanide bridges, while in [Cu(en or tn)2]2[Fe(CN)6]·nH2O, no cyanide bridge is present. The thermal reactions of the complexes in the solid state were investigated by means of derivatography under dynamic conditions (D conditions). It was found that dehydration from [Cu(en)2Fe(CN)6]·nH2O resulted in formation of cyanide bridge in the apical position of square planer [Cu(en)2]2+. For [(Cu(dien or dpt))2(NC)2Fe(CN)4]·4H2O, dehydration resulted in the formation of additional cyanide bridges. All the complexes showed metal to metal (iron(II) to copper(II)) charge-transfer transitions (MMCT) in the near ultraviolet or visible region. The complexes, [Cu(en or tn)2]2[Fe(CN)6]·nH2O, exhibited the outer sphere iron(II) to copper(II) charge-transfer bands (OSMMCT) in the near ultra-violet region. [(Cu(dien or dpt))2(NC)2Fe(CN)4]·4H2O and the dehydrated complexes prepared by thermal reaction showed the inner-sphere iron(II) to copper(II) charge transfer bands (ISMMCT) in the visible region. A good correlation was observed between the energies of the MMCT and the d-d band maxima of copper(II) ions.
続きを見る
|
||||
| 5.
論文 |
論文
|
鈴木, 正樹 ; Suzuki, Masatatsu
概要:
生体系では二核鉄錯体により酸素分子の結合や活性 化がいともたやすく行われている。このような機能 を持つ二核鉄錯体の分子設計はどのようにしたら可 能なのだろうか｡
|
||||
| 6.
論文 |
論文
|
Kayatani, Takayuki ; Hayashi, Yoshihito ; Suzuki, Masatatsu ; Inomata, Katsuhiko ; Uehara, Akira
概要:
A dicopper(II) complex with a novel unsymmetric dinucleating ligand, H2L-1, which can provide donor atom, coordination n
…
umber, and geometric asymmetries at metal centers, [Cu2(L-1)(CH3COO)]ClO4·H2O·0.5NaClO4 (1), was synthesized, where H2L-1 is a racemic 1-bis(2-pyridylmethyl)amino-3-salicylideneaminopropan-2-ol. The ligand is a hybrid one of 1,3-bis[bis(2-pyridylmethyl)amino]propan-2-ol (Htpdp) and 1,3-bis(salicylideneamino)propan-2-ol (H3L-2). Crystal structure of 1 was determined by X-ray crystallography. Complex 1 crystallizes in monoclinic space group C2/c with a = 42.704(8), b = 12.689(6), c = 29.008(9) Å, β = 128.28(1)°, and Z = 16. The crystal structure showed that two stereoisomers (1a and 1b) are present in solid state. This is attributable to the presence of an enantiomeric pair of L-1. Dinuclear cations consist of one square-planar site with a NO3 donor set and one five-coordinate site with a N3O2 donor set, which are linked by an endogenous alkoxide bridge of L-1 and an exogenous acetate bridge. A powdered sample of 1 shows weak antiferromagnetic interaction (2.60 B.M./Cu2 at 300 and 1.81 B.M./Cu2 at 5 K). Cryomagnetic data is analyzed using two exchange coupling constants, J1 = −0.18 cm−1 and J2 = −9.05 cm−1. EHMO calculations revealed that the observed weak antiferromagnetic interaction(s) compared with that found for [Cu2(L-2)(CH3COO)] (3) (J = −85 cm−1) is reasonably interpreted in terms of the energy gap and the nature of HOMO and LUMO. Some other physicochemical properties of the complex are discussed in comparison with those of the parent complexes, [Cu2(tpdp)(CH3COO)]2+ (2) and [Cu2(L-2)(CH3COO)] (3).
続きを見る
|
||||
| 7.
論文 |
論文
|
Suzuki, Masatatsu ; Sugisawa, Toshiharu ; Uehara, Akira
概要:
Two dinuclear cobalt(II,II) complexes, [Co2(tpdp)(CH3COO)](ClO4)2·0.5H2O (1) and [Co2(tmdp)(CH3COO)](ClO4)2·H2O (2), wer
…
e prepared, where Htpdp and Htmdp are 1,3-bis[bis(2-pyridylmethyl)amino]-2-propanol and 1,5-bis[bis(2-pyridylmethyl)amino]-3-pentanol respectively. Their electronic spectral and magnetic data revealed that 1 and 2 are five-coordinate in the high-spin state, in the same manner as [Co2(bpmp)(CH3COO)]2+ (3) (Hbpmp=2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol). The complexes reacted with molecular oxygen to form μ-peroxo complexes in dichloromethane and acetonitrile. The oxygen affinity of the complexes decreased in the order of 3>2>1. The relationships between the oxygen affinities and (1) the donor abilities of dinucleating ligands, (2) the energies of the charge-transfer bands (O22− to Co3+) of the μ-peroxo complexes, and (3) the redox potentials of the Co3+–O2−–Co3+/Co3+–O22−–Co3+ couple indicated that a steric effect arising from the dinucleating ligands contributes significantly to the oxygen affinities of the complexes.
続きを見る
|
||||
| 8.
論文 |
論文
|
Komiyama, Kazuya ; Furutachi, Hideki ; Nagatomo, Shigenori ; Hashimoto, Akifumi ; Hayashi, Hideki ; Fujinami, Shuhei ; Suzuki, Masatatsu ; Kitagawa, Teizo
概要:
Oxygenation of copper(I) with tetradentate tripodal ligands (L) comprised of a tris(aminoethyl)amine (tren) skeleton hav
…
ing sterically bulky substituent(s) on the terminal nitrogens has been investigated, where L = tris(N-benzylaminoethyl)amine (LH,Bn), tris(N-benzyl-N-methylaminoethyl)amine (LMe,Bn), or tris(N,N-dimethylaminoethyl)amine (LMe,Me). All the copper(I) complexes reacted with dioxygen at low temperatures to produce superoxocopper(II) and/or trans-(μ-1,2-peroxo)-dicopper(II) complexes depending on the steric bulkiness of the terminal nitrogens and the reaction conditions. The reaction of a copper(I) complex [Cu(LH,Bn)]+ at −90 °C in acetone resulted in the formation of a superoxo complex [Cu(LH,Bn)(O2)]+ as a less stable species and a peroxo complex [{Cu(LH,Bn)}2(O2)]2+ as a stable species. The structures of [Cu(LH,Bn)]ClO4 and [{Cu(LH,Bn)}2(O2)](BPh4)2·8(CH3)2CO were determined by X-ray crystallography. [{Cu(LH,Bn)}2(O2)]2+ has a trans-(μ-1,2-peroxo)-dicopper(II) core with a trigonal bipyramidal structure. The O–O bond distance is 1.450(5) Å with an intermetallic Cu···Cu separation of 4.476(2) Å. The resonance Raman spectrum of [{Cu(LH,Bn)}2(O2)]2+ measured at −90 °C in acetone-d6 showed a broad ν(O–O) band at 837–834 cm−1 (788 cm−1 for an 18O labeled sample) and two ν(Cu–O) bands at 556 and 539 cm−1, suggesting the presence of two peroxo species in solution. [Cu(LMe,Bn)]+ also produced both superoxo and trans-μ-1,2-peroxo species, [Cu(LMe,Bn)(O2)]+ and [{Cu(LMe,Bn)}2(O2)]2+. At a lower concentration of [Cu(LMe,Bn)]+ (∼0.24 mM) and higher dioxygen concentration (P(O2) = ∼1 atm), the superoxo species is predominantly formed, whereas at a higher concentration of [Cu(LMe,Bn)]+ (∼1 mM) and lower dioxygen concentration (P(O2) = ∼0.02 atm) the formation of the peroxo species is observed. The resonance Raman spectrum of [Cu(LMe,Bn)(O2)]+ (∼1 mM) in acetone-d6 at ∼−95 °C exhibited a ν(O–O) band at 1120 cm−1 (1059 cm−1 for an 18O labeled sample) and that of [{Cu(LMe,Bn)}2(O2)]2+ (∼3 mM) in acetone-d6 at ∼−90 °C showed two ν(O–O) bands at 812 and 797 cm−1 (767 and 753 cm−1 for an 18O labeled sample), respectively. A similar observation was also made for [{Cu(LMe,Me)}2(O2)]2+. Relationships between the energies of the LMCT and d–d transitions and those of the ν(O–O) and ν(Cu–O) stretching vibrations and the steric constraints in the Cu(II)–(O22−)–Cu(II) core are discussed.
続きを見る
|
||||
| 9.
論文 |
論文
|
Sugimoto, Hideki ; Nagayama, Toshihiko ; Maruyama, Sachihito ; Fujinami, Shuhei ; Yasuda, Yuichi ; Suzuki, Masatatsu ; Uehara, Akira
概要:
A new dinucleating ligand containing a sterically bulky imidazolyl group, Ph-Htidp (N,N,N′,N′-tetrakis[(1-methyl-4,5-dip
…
henyl-2-imidazolyl)methyl]-1,3-diamino-2-propanol), and its μ-alkoxo-diiron(II) complexes [Fe2(Ph-tidp)(RCO2)](ClO4)2, (RCO2 = C6H5CO2 (1), C6F5CO2 (2), CF3CO2 (3), and C2H5CO2 (4)), were synthesized. The structure of complex 1 was determined by X-ray crystallography. Complex 1 crystallizes in the monoclinic space group P21/c with a = 13.464(2), b = 19.223(4), c = 31.358(4) Å, β = 92.84(2)°, and Z = 4. The complex has a doubly-bridged structure with μ-alkoxo of Ph-tidp and μ-benzoate; the two iron centers have a distorted five-coordinate structure with N3O2 donor set. All the complexes showed fairly good reversible oxygenation below −30 °C in CH2Cl2, which was monitored by UV-vis and NMR spectroscopies, and dioxygen up-take measurements. Introduction of 4,5-diphenyl substituents into 2-imidazolyl group stabilized the μ-peroxo diiron species against irreversible oxidation, just as introduction of 6-methyl substituent into 2-pyridyl group did. Phenyl substituents appear to weaken the electron donor ability of a dinucleating ligand to stabilize divalent oxidation state of iron and to form a hydrophobic cavity for a O2 binding site, which would suppress the irreversible oxidation and facilitate the reversible oxygenation. Dioxygen affinities of the Ph-tidp and Me4-tpdp diiron(II), and the tpdp and bpmp dicobalt(II) complexes were measured, [Fe2(Me4-tpdp)(RCO2)]2+ (RCO2 = C6H5CO2 and RCO2 = CF3CO2) and [Co2(L)(RCO2)]2+ (L = tpdp, RCO2 = CH3CO2, and L = bpmp, RCO2 = C6F5CO2, and CF3CO2), where Me4-tpdp, tpdp, and bpmp are N,N,N′,N′-tetrakis[(6-methyl-2-pyridyl)methyl]-1,3-diamino-2-propanolate, N,N,N′,N′-tetrakis(2-pyridylmethyl)-1,3-diamino-2-propanolate, and 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenolate, respectively. Within a series of the Ph-tidp diiron(II) complexes, dioxygen affinity is well correlated with electron donor ability of bridging carboxylates (1 (C6H5CO2) > 2 (C6F5CO2) > 3 (CF3CO2)). In contrast to the above trend, dioxygen affinities of the Ph-tidp complexes are lower than those of the Me4-tpdp complexes, although electron donor abilities of the Me4-tpdp complexes are weaker than those of the Ph-tidp complexes. Significant enhancement of dioxygen affinity was observed for both iron and cobalt complexes with 2,6-bis(aminomethyl)phenolate bridging skeleton compared to the complexes with a 1,3-diamino-2-propanolate bridging one. Thermodynamic study suggested that the observed enhancement is mainly attributable to a favorable entropy effect along with a steric effect.
続きを見る
|
||||
| 10.
論文 |
論文
|
Hishiki, Masanobu ; Suzuki, Masatatsu ; Uehara, Akira
|
