※一部利用できない機能があります
| 1.
論文 |
論文
|
Ihara, Yoshinori ; Tsuchiya, Ryokichi
概要:
The following ten nickel(II) complexes with meso- or dl-1,2-diphenyl-1,2-ethanediamine (abbreviated as meso-stien and dl-stien, respectively) were prepared, and their thermal behavior was investigated in the
…
solid phase: [Ni(meso-stien)2]X2 (X=Cl, Br, I, NO3, or ClO4), [Ni(dl-stien)2]X2 (X=I or ClO4), and [Ni(H2O)2(dl-stien)2]X2 (X=Cl, Br, or NO3). The square planar bis(dl-stien) complex chloride, bromide, and nitrate obtained by thermal dehydration of their respective octahedral diaqua complexes were found by various techniques to be transformed, upon further heating, to the octahedral diacido bis(dl-stien) complexes. The complexes containing dl-stien have a stronger tendency to show such structural transformations than those containing meso-stien. The reason for this difference is discussed.
続きを見る
|
||||
| 2.
論文 |
論文
|
Yoshimura, Osamu ; Ueda, Kazumasa ; Yamamoto, Yoshikazu
概要:
2-(2-Thiazolylazo)-4-methoxyphenol (TAMP) forms a brownish 2:1 complex with iron(ll) in the presence of ascorbic acid; t
…
he complex has a characteristic absorption at 784 nm in chloroform. By utilizing this peculiar absorption, selective spectrophotometry determination of iron has been developed. The optimum pH for iron extraction lies between 5.0-9.3 and Beer's law holds up to 5.0 ng/ml of iron. Many type of ions are tolerable. The method was successfully applied to the determination of iron in river waters. The extraction constant of iron(ll) complex was log Kex=-2.50±0.12 and the extraction mechanism was kinetically investigated. The complexation rate was first-order with respect to iron(ll) and TAMP concentrations and independent of ascorbic acid concentration. From these results, the major extraction rate-determining step was concluded to be a 1:1 complexation reaction between iron(ll) and dissociated TAMP. Kinetic data and activation parameters for the first-order reaction were determined and discussed. © 1988, The Japan Society for Analytical Chemistry. All rights reserved.
続きを見る
|
||||
| 3.
論文 |
論文
|
Sakurai, Ikuo ; Suzuki, Harumi ; Shimizu, Sakae ; Yamamoto, Yuzuru
概要:
It was found that Macrophoma commelinae (IFO 9570) had an ability to transform 5-acetyl-4-methoxy-6-methyl-2-pyrone (1) to 4-acetyl-3-methoxy-5-methylbenzoic acid (2). This biotransformation was investigated using 13C- and 14C-labeled
…
compounds. It is likely that 2 is formed by condensation of the added 2-pyrone and a catabolic pyruvate.
続きを見る
|
||||
| 4.
論文 |
論文
|
Kodama, Akio
|
||||
| 5.
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
|
||||
| 6.
論文 |
論文
|
Ihara, Yoshinori ; Wada, Akiko ; Fukuda, Yutaka ; Sone, Kozo
概要:
Nickel(II) complexes of 1,2-butanediamine(1,2-bn) and 3,3-dimethyl-1,2-butanediamine(dmbn), were prepared, and their the
…
rmal behavior was investigated in solid phase. The original complexes were all violet, octahedral diaquabis(diamine) complexes([Ni(H2O)2(1,2-bn/dmbn)2]X2; X=Cl, Br, NO3, or ClO4). The 1,2-bn complexes with Cl− or Br− and the dmbn complex with NO3− showed a two-step thermochromism, violet→yellow→violet blue, upon heating. These steps correspond to structural changes to a square planar anhydride, and then to an octahedral dianiono complex. The complexes of both ligands with ClO4− underwent only thermal deaquation, changing into orange square planar anhydride. Other salts, the 1,2-bn complex with NO3− and the dmbn complexes with Cl− or Br−, were converted into octahedral dianiono complexes by thermal deaquation-anation which occurs in one step. The differences among the thermal reactivities of the complexes with different diamines can be understood on the basis of steric hindrance caused by the substituent groups on the diamine.
続きを見る
|
||||
| 7.
論文 |
論文
|
Sakurai, Ikuo ; Shimizu, Sakae ; Yamamoto, Yuzuru
概要:
Three new metabolites, named macommelinal, macrophin and macrophic acid, were isolated from the culture broth of Macrophoma commelinae IFO 9570. Their structures were determined to be
…
2-(4-methoxy-6-methyl-2-oxo-2H-pyran-5-yl)ethanal, 3-methyl-2-butenoic acid (E)-[5-hydroxymethyl-4-methoxy-6-(2-methoxycarbonylethenyl)-2-oxo-2H-pyran-3-ly]methyl ester and 3-(4-methoxy-3,5-dimethyl-2-oxo-2H-pyran-6-yl)-2-propenoic acid, respectively. 4 Acetyl-3-methoxy-5-methylbenzoic acid, now named macrophomic acid, was also isolated from a large-scale culture.The biosynthesis of the macommelin group, novel 5-substituted 2-pyrone metabolites, has been investigated by feeding experiments with [1-^<13>C]-, [1,2-^<13>C_2]- and [1-^<13>C, 2-^2H_3]acetate and [2-^<13>C]malonate. It was concluded that all these metabolites originated from a single straight tetraketide chain. Furthermore, the biogenetic mutual relationships of these metabolites including potential intermediates were estabished through incorporation experiments with ^<14>C-labeled compounds.
続きを見る
|
||||
| 8.
論文 |
論文
|
Fujii, Tozo ; Ohba, Masashi
概要:
8-Hydroxyprotoemetine [(-)-2f], an aldehyde of biogenetic interest, has been synthesized for the first time from the tri
…
cyclic ester (-)-5 through the intermediate (-)-6. Wolff-Kishner reduction of (-)-2f produced the 2-ethyl congener (-)-2g. As a result of these syntheses, the circular dichroism (CD) spectra of (-)-2f・HClO_4 and (-)-2g in 0.1 N aqueous HCl and in EtOH, together with those of the Alangium alkaloids ankorine (2d) and alancine (2e), are now availale.
続きを見る
|
||||
| 9.
論文 |
論文
|
Hishiki, Masanobu ; Suzuki, Masatatsu ; Uehara, Akira
|
||||
| 10.
論文 |
論文
|
Ihara, Yoshinori
概要:
Nickel(II) complexes [Ni(phenen)2](ClO4)2 and [Ni(H2O)2(phenen)2]X2 (phenen=1-phenyl-1,2-ethanediamine, X=Cl, Br, or NO3
…
) were prepared, and their thermal behavior was investigated in the solid phase. The nitrate showed a thermochromism consisting of two steps, violet→yellow→violet, which corresponds to a structural change from an octahedral diaqua complex to a square planar anhydride, and then to the octahedral dinitrato complex, respectively. Both the chloride and bromide were converted into the octahedral dianiono complexes by thermal deaquation-anation, retaining their octahedral configuration. However, no change was observed in the perchlorate, which is invariably square planar.
続きを見る
|
