Papers - Yoshioka, Naoki

Stress-Induced Ligand Field Distortion and Consequent Multi-Mode Spin Crossover Behavior in Fe(phen)2(NCS)2 and Fe[HB(pz)3]2

TSUCHIYA NAOKO, TSUKAMOTO ATSUSHI, OHSHITA TADASHI, ISOBE TETSUHIKO, SENNA MAMORU, YOSHIOKA NAOKI, INOUE HIDENARI

Solid State Sciences 3 ( 6 ) 705 - 714 2001.08

Joint Work, Accepted

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Changes in the nature of spin crossover caused by mechanical stressing exerted on the crystalline powders were studied for FeII(phen)2(NCS)2 (phen = 1,10-phenanthroline) and FeII[HB(pz)3]2 (pz = pyrazol-1-yl) by means of a multi-component fitting of the temperature dependence of magnetic susceptibility. The analysis revealed the development and broadening of the ligand field distribution as a consequence of mechanical stressing. This was confirmed by the broadening of Mössbauer and far-infrared spectra.

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Ligand-Exchange Reaction between Tris(1,10-phenanthroline)metal(II) and　Tris(4,7-diphenyl-　1,10-phenanthroline)metal(II) Ions

MUDASIR, YOSHIOKA NAOKI, INOUE HIDENARI

Journal of Coordination Chemistry 52 ( 4 ) 333 - 344 2001.07

Research paper (scientific journal), Joint Work, Accepted

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The ligand exchange reaction between [M(phen)3]2+ and [M(DIP)3]2+ (where M is the same and M = FeII or NiII, phen = 1,10-phenanthroline, DIP = 4,7-diphenyl-1,10-phenanthroline) has been investigated by reversed phase ion-paired chromatography (RP-IPC). The effect of pH and solvent on the ligand-exchange reaction is studied by monitoring the variation in chromatograms with time after mixing. The results have shown that the ligand exchange reaction between [M(phen)3]2+ and [M(DIP)3]2+ takes place in the pH range of 3–8 and the rate of reaction for nickel(II) complexes is about two times slower than that for iron(II) complexes. Experiments on the effect of various solvents on the ligand-exchange reaction have revealed that the rate of reaction is enhanced by the solvent in the following order: (CH3)2CO > CHCl3 ≥ CH2Cl2 > CH3CN > CH3OH. Elemental analysis and UV-visible spectroscopy confirmed that the products obtained from the ligand-exchange reaction are mixed-ligand complexes containing phen and DIP ligands, i.e., [M(phen)2(DIP)]2+ and [M(phen)(DIP)2]2+.

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Metallopyrazoliumylporphyrins with Calf Thymus DNA

TJAHJONO H. DARYONO, MIMA SHUNSUKE, AKUTSU TAKEHIRO, YOSHIOKA NAOKI, INOUE HIDENARI

Journal of Inorganic Biochemistry 85 ( 2-3 ) 219 - 228 2001.06

Research paper (scientific journal), Joint Work, Accepted

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The interaction of transition metal complexes of cationic porphyrins bearing five membered rings, meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin (MPzP, M=MnIII, NiII, CuII or ZnII), with calf thymus DNA (ctDNA) has been studied. Metalloporphyrins NiPzP and CuPzP are intercalated into the 5′GC3′ step of ctDNA. MnPzP is bound edge-on at the 5′TA3′ step of the minor groove of ctDNA, while ZnPzP is bound face-on at the 5′TA3′ step of the major groove of ctDNA. The binding constants of the metalloporphyrins to ctDNA range from 1.05×105 to 2.66×106 M−1 and are comparable to those of other reported cationic porphyrins. The binding process of the metallopyrazoliumylporphyrins to ctDNA is endothermic and entropically driven. These results have revealed that the kind of central metal ions of metalloporphyrins influences the binding characteristics of the porphyrin to DNA.

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Synthesis and Magnetic Properties of Nitronyl Nitroxide Radicals Carrying a Purine Ring

NAGASHIMA HIDEAKI, YOSHIOKA NAOKI, INOUE HIDENARI

Polyhedron 20 ( 11-14 ) 1151 - 1155 2001.05

Research paper (scientific journal), Joint Work, Accepted

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2-(Purin-8-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide (Pu-NN) was designed and synthesized. Two crystalline phases (α- and β-phases) exhibiting different IR spectral patterns at the νNH region were obtained depending on the crystallizing condition. The temperature dependences of the magnetic susceptibility of these two phases followed Curie–Weiss law with θ=−5.7 K (α-phase) and θ=−0.3 K (β-phase) implying intermolecular antiferromagnetic interaction, which were quite different from that of parent benzimidazole derivative, 2-(benzimidazol-2-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H- imidazolyl-1-oxyl-3-oxide that formed a 1-D ferromagnetic chain induced by an intermolecular hydrogen bonding.

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Synthesis and Magnetic Properties of a Polymeric Nitridochromium(V) Complex with a Tetradentate Schiff Base Ligand

TSUCHIMOTO MASANOBU, YOSHIOKA NAOKI, OHBA SHIGERU

European Journal of Inorganic Chemistry 2001 ( 4 ) 1045 - 1049 2001.03

Research paper (scientific journal), Joint Work, Accepted

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A novel polymeric nitridochromium(V) complex with a Schiff base ligand [CrN(salpn)] [H2(salpn) = N,N′‐disalicylidene‐1,3‐propanediamine] was prepared by photolysis of an azidochromium(III) complex in acetonitrile. X‐ray crystal structure analyses of the starting material {(CH3)2NH2}2[CrCl2(salpn)]Cl (1) and the polymeric complex [CrN(salpn)] (3) were carried out. The orange complex 3 has a linear ···Cr≡N···Cr≡N··· chain structure with the N···Cr distance being 2.508(2) Å. Magnetic data show that 3 has a ferromagnetic intermolecular interaction in the chains (J = +8.4 cm−1).

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Synthesis and Magnetic Properties of Nitronyl Nitroxide radicals Carrying a Purine Ring

吉岡 直樹

Polyhedron 20   1151-1155 2001.03

Research paper (scientific journal), Single Work, Accepted

Formation of Cyclic Trimers and Tetramers of Zinc(II) Pyrazolylporphyrins by Mutual Coordination

IKEDA CHUSAKU, NAGAHARA NORIKO, YOSHIOKA NAOKI, INOUE HIDENARI

New Journal of Chemistry 24   897 - 902 2000.09

Research paper (scientific journal), Joint Work, Accepted

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The self-assembly of zinc(II) porphyrins bearing a pyrazole substituent are reported. 1H NMR, UV/Vis and VPO measurements indicate the formation of a cyclic trimer of zinc(II) pyrazol-4-ylporphyrin and a tetramer of zinc(II) 3,5-dimethypyrazol-4-ylporphyrin by mutual coordination.

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Synthesis and DNA-Binding Properties of Cationic Bisdiazolium Porphyrins

TJAHYONO H. DARYONO, YAMAMOTO TOMOKO, ICHIMOTO SUMITO, YOSHIOKA NAOKI, INOUE HIDENARI

Journal of the Chemical Society, Perkin Transactions 1 2000 ( 18 ) 3077 - 3081 2000.08

Research paper (scientific journal), Joint Work, Accepted

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A pair of 5,15-bisdiazoliumylporphyrins with only two meso-substituents, 5,15-bis(1,3-dimethylimidazolium-2-yl)porphyrin 1b and 5,15-bis(1,2-dimethylpyrazolium-4-yl)porphyrin 2b, has been synthesized. The crowded porphyrin 1b intercalates between base pairs of DNA to stabilize the duplex DNA to thermal denaturation due to its high affinity for DNA. The binding of porphyrin 1b to DNA is an exothermic interaction and enthalpically driven. Porphyrin 1b interacts more strongly with poly(dA-dT)2 than with poly(dG-dC)2, and the interaction is more favorable or selective to AT-rich sites than to GC-rich sites.

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Mechanochemical Reaction of Polymeric Oxovanadium(IV) Complexes with Schiff Base Ligands Derived from 5-Nitrosalicylalde and Diamines

TSUCHIMOTO MASANOBU, HOSHINA GAKUSE, YOSHIOKA NAOKI, INOUE HIDENARI, NAKAJIMA KIYOHIKO, KAMISHIMA MAYOMI, KOJIMA MASAAKI, OHBA SHIGERU

Journal of Solid State Chemistry 153 ( 1 ) 9 - 15 2000.08

Research paper (scientific journal), Joint Work, Accepted

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Light brown [VO(5-NO2salen)]·2H2O (1; H2(5-NO2 salen)=N,N′-di-5-nitrosalicylidene-1,2-ethanediamine) and orange [VO(5-NO2sal-meso-stien)]·0.5H2O (2; H2(5-NO2sal-meso-stien)=N,N′-di-5-nitrosalicylidene-(R,S)(S,R)-1,2-diphenyl-1,2-ethanediamine) which have linear chain structures in the solid state turn dark brown and yellow-brown, respectively, when ground thoroughly in mortars. The IR spectra of 1 and 2 in Nujol mulls show strong V=O stretching bands at 875 and 905 cm−1, respectively. On the other hand, the spectra of the finely ground complexes in Nujol mulls show very weak V=O stretching bands. X-ray powder diffraction patterns of the ground complexes scarcely show diffraction peaks. The spectroscopic and magnetic data suggest that the linear chain structures in the crystals of 1 and 2 are destroyed on grinding to yield the fragments of the polymeric chains.

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Optical Studies of the Monolayer Films of Diazole-Containing Porphyrins at the Air-Water Interface

IKEDA CHUSAKU, TAKASHIMA YUFUKO, IRIE TAKESHI, YOSHIOKA NAOKI, INOUE HIDENARI

Molecular Crystals and Liquid Crystals Science and Technology. Section A. 342 ( 1 ) 81 - 86 2000.08

Research paper (scientific journal), Joint Work, Accepted

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Optical properties of the monolayers of 5-(1-methyliniidazol-2-yl)- 10,15,20-tris(p-octyloxy-phenyl)porphyrin, 5-(1-methylpyrazol-4-yl)-10,15,20-tris(p-octyloxyphenyl)porphyrin and their zinc(II) complexes have been studied. The π-A isotherms and UV-vis spectra have revealed that the zinc(II) complexes form coordination assemblies between peripheral nitrogen atom and central zinc(II) ion at the air-water interface with very tight molecular packing.

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Thermal Decomposition of Prussian Blue Analogues of the Type Fe[Fe(CN)5NO]

INOUE HIDENARI, NARINO SHUICHI, YOSHIOKA NAOKI, FLUCK EKKEHARD

Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences 55   685 - 690 2000.08

Research paper (scientific journal), Joint Work, Accepted

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The structure and properties of the thermal decomposition products of Fe[Fe(CN)5NO] · x H2O (x = 5 ~ 6) have been studied by Mössbauer and FT-IR spectroscopy, X-ray diffraction, and conductivity measurements. The valence state and coordination environment of the iron ions change dramatically when the nitrosyl ligand is eliminated by heat-treatment under vacuum at 200 °C. The dark blue product obtained by heat-treatment under vacuum at 250 °C is characteristic of the mixed-valence state in Prussian blue analogues. The electrical conductivity of the dark blue product is higher by a factor of 103 than that of the starting material because of the mixed-valence state between Fe(III)[Fe(II)(CN)5] and Fe(II)[Fe(III)(CN)5]. Heat-treatment under vacuum at 350°C yields a new product Fe(II)[Fe(II)(CN)4] the crystal structure of which is different from that of the starting material. The electrical conductivity of the decomposition product obtained at 350 °C is about 105 times higher than that of the starting material.

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DNA Binding of Iron(II) Mixed-Ligand Complexes Containing 1,10-Phenanthroline and 4,7-Diphenyl-1,10-phenanthroline

Mudasir, YOSHIOKA NAOKI, INOUE HIDENARI

Journal of Inorganic Biochemistry 77 ( 3-4 ) 239 - 247 1999.11

Research paper (scientific journal), Joint Work, Accepted

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Absorption spectroscopy and circular dichroism (CD) have been used to characterize the DNA binding of [Fe(phen)3]2+, [Fe(phen)2(DIP)]2+ and [Fe(phen)(DIP)2]2+ where phen and DIP stand for 1,10-phenanthroline and 4,7-diphenyl-1,10-phenanthroline, respectively. Both [Fe(phen)3]2+ and [Fe(phen)2(DIP)]2+ bind weakly to calf thymus DNA (CT-DNA) in an electrostatic mode, while [Fe(phen)(DIP)2]2+ binds more strongly to CT-DNA, possibly in an intercalation mode. The hypochromicity, red shift and Kb increase in the order [Fe(phen)3]2+<[Fe(phen)2(DIP)]2+<[Fe(phen)(DIP)2]2+ in accordance with the increase in size and hydrophobicity of the iron(II) complexes. The thermodynamic parameters obtained suggest that the DNA binding of both [Fe(phen)3]2+ and [Fe(phen)2(DIP)]2+ is entropically driven, while that of [Fe(phen)(DIP)2]2+ is enthalpically driven. A strong CD spectrum in the UV and visible region develops upon addition of CT-DNA into the racemate solution of each iron(II) complex (Pfeiffer effect). This has revealed that a shift in diastereomeric inversion equilibrium takes place in the solution to yield an excess of one of the DNA-complex diastereomers. The striking resemblance of the CD spectral profiles to those of the pure Δ-enantiomer indicates that the Δ-enantiomer of the iron(II) complexes is preferentially bound to CT-DNA. The mechanism of the development of Pfeiffer CD is proposed on the basis of kinetic studies on the DNA binding of the racemic iron(II) complexes.

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Magnetic Properties of Nitronyl Nitroxide Derivatives Bearing N-H Site: an Approach to Ferromagnetic Self-Assemblies Using Hydrogen Bond

YOSHIOKA NAOKI, MATSUOKA NAOKI, IRISAWA MUNETOSHI, OHBA SHIGERU, INOUE HIDENARI

Molecular Crystals and Liquid Crystals Science and Technology. Section A. Vol. 334 ( 1 ) 239 - 246 1999.11

Research paper (scientific journal), Joint Work, Accepted

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Abstract
Nitronyl nitroxide derivatives bearing NH site, imidazolyl-2-nitronyl nitroxide (Im-NN), 4(5)-methyl-imidazolyl-2-nitronyl nitroxide (MeIm-NN), and benzimidazolyl-2-nitronyl nitroxide (BIm-NN) were synthesized, and were self-assembled by hydrogen bonding at NH site with nitrogen atom on imidazole ring or oxygen atom of nitroxide moiety. Ferromagnetic intermolecular interactions were observed in MeIm-NN and BIm-NN. The magnetic interaction can be rationally explained by McConnell model.

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Cationic porphyrins bearing diazolium rings: synthesis and their interaction with calf thymus DNA

TJAHJONO H. DARYONO, YOSHIOKA NAOKI, INOUE HIDENARI

Biochimica et Biophysica Acta 1472 ( 1-2 ) 333 - 343 1999.10

Research paper (scientific journal), Joint Work, Accepted

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Two novel cationic porphyrins bearing five-membered rings at the meso-positions, meso-tetrakis(1,3-dimethylimidazolium-2-yl)porphyrin (H2TDMImP) and meso-tetrakis(1,2-dimethylpyrazolium-4-yl)porphyrin (H2TDMPzP), have been synthesized. These two compounds interact with calf thymus DNA (CTDNA) in different binding modes from that of meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (H2TMPyP). H2TDMImP outside binds to the minor groove of CTDNA while H2TDMPzP intercalates into CTDNA. These two novel cationic porphyrins strongly bind to CTDNA even at high ionic strength and the binding constant of H2TDMPzP to CTDNA is comparable to that of H2TMPyP. The binding of H2TDMImP to CTDNA is enthalpically driven. The favorable free energy changes in binding of H2TDMPzP to CTDNA come from the large negative enthalpy changes accompanied by small positive entropy changes.

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Self-Assembly of Monopyrazolylporphyrins by Hydrogen Bonding in Solution

IKEDA CHUSAKU, NAGAHARA NORIKO, MOTEGI EIKO, YOSHIOKA NAOKI, INOUE HIDENARI

Chemical Communications Vo1 1999   1759 - 1760 1999.09

Research paper (scientific journal), Joint Work, Accepted

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The self-associated structures of two noble meso-(monopyrazolyltritolyl)porphyrins synthesized via their NH-protected precursors have been studied by 1H NMR, FT-IR and ESI MS measurements; meso-(pyrazol-4-yl)porphyrin and meso-(3,5-dimethylpyrazol-4-yl)porphyrin form a dimer and a tetramer, respectively, in solution due to intermolecular hydrogen bonding between pyrazole units.

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Iron(II) and Nickel(II) Mixed-Complexes Containing 1,10-Phenanthroline and 4,7-Diphenyl-1,10-phenanthroline

MUDASIR, YOSHIOKA NAOKI, INOUE HIDENARI

Transition Metal Chemistry Vol. 24 ( 2 ) 210 - 217 1999.06

Research paper (scientific journal), Joint Work, Accepted

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Two types of mixed-ligand complexes, i.e. [M(phen)2 (dip)]2+ and [M(phen)(dip)2]2+ (M = iron(II) and nickel(II); phen = 1,10-phenanthroline and dip = 4,7-diphenyl-1,10-phenanthroline) have been prepared from their related tris-complexes, [M(phen)3]2+ by ligand substitution, and isolated by semi-preparative HPLC. Elemental and chromatographic analyses confirm the purity of the isolated complexes while u.v./vis and i.r. spectra were used to identify and characterize them. 1H-n.m.r. and room temperature Mössbauer spectra of the iron(III) complexes were also measured and the results are discussed. In addition, our preliminary results on hypochromicity in the MLCT band and circular dihroism (CD) emerging in the u.v./vis region upon addition of CT(calf thymus)-DNA to the racemic complexes indicated that the iron(II) mixed-ligand complexes interact with CT-DNA.

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Polymerization of (p-Vinylphenyl) hydrogalvinoxyl and Formation of a Stable Polyradical Derivative

KANEKO TAKASHI, TATSUMI HIROYUKI, AOKI TOSHIKI, OIKAWA EIZO, YOSHIOKI HAJIME, YOSHIOKA NAOKI, TSUCHIDA EISHUN, NISHIDE HIROYUKI

Journal of Polymer Science, Part A Polymer Chemistry 37 ( 2 ) 189 - 198 1999.01

Research paper (scientific journal), Accepted

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4‐[(3,5‐Di‐tert‐butyl‐4‐hydroxyphenyl)(3,5‐di‐tert‐butyl‐4‐oxo‐cyclohexa‐ 2,5‐dienylidene)methyl]styrene (abbreviated as (p‐vinylphenyl)hydrogalvinoxyl) was polymerized using AIBN as an initiator to give a bright yellow polymer with Mw = 3.2 × 104. The polymer was oxidized to give the corresponding polyradical derivative, whose spin concentration could be increased up to about 70 mol % depending on oxidative conditions. ESR signal line‐width in the solid state was greatly increased below 200 K for the polyradical with a high spin concentration (> 50 mol %). The magnetization and magnetic susceptibility indicated weak antiferromagnetic interaction among the radical sites.

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Magnetic Properties of Polynuclear Oxovanadium(Ⅳ) Complexes with Tetradetate Schiff Base Ligands

TSUCHIMOTO MASANOBU, YOSHIOKA NAOKI

Chemical Physics Letters 297 ( 1-2 ) 115 - 120 1998.11

Research paper (scientific journal), Joint Work, Accepted

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Temperature dependence measurements of magnetic susceptibilities and low-temperature magnetization of tetradentate Schiff base–oxovanadium(IV) complexes, [VO(salpn)] (1), [VO(5-NO2salen)]·2H2O (2), and [VO(3-EtOsal-meso-stien)]·H2O (3) were carried out. Orange 1 and brown 2, which take linear chain structures (VO⋯VO⋯) in the solid state, show dominant ferromagnetic intermolecular interactions (J=+5.2 and +5.7 cm−1, respectively) on which very weak antiferromagnetic interactions between the chains are superimposed. However, green 3, which takes a fairly elongated linear chain structure (V⋯O distance: 4.060(2) Å) in the crystal, shows an isolated doublet state.

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Magnetic Properties of Nitronyl Nitroxide Derivatives Bearing N-H Site: An Approach to Ferromagnetic Self-Assemblies Using Hydrogen Bond

Naoki Yoshioka, N. Matsuoka, Munetoshi Irisawa, Shigeru Ohba, Hidenari Inoue

Molecular Crystals and Liquid Crystals 334   239-246 1998.10

Research paper (scientific journal), Joint Work, Accepted

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N-H水素結合部位を有するニトロニルニトロキシドラジカルの磁気特性に対するイミダゾール導入置換基の影響を報告した。（９頁）

Mossbauer Spectroscopic Characterization of the Light-Induced Mixed-Valence State in Fe[Fe(CN)5NO]・xH2O

INOUE HIDENARI, YOSHIOKA NAOKI, MORIOKA YOSHIYUKI

Hyperfine　Interactions (C) 3   113 - 116 1998.08

Research paper (scientific journal), Joint Work, Accepted

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Fe[Fe(CN)5NO]・xH2Oに光照射した際に観測される磁気特性の変化を報告した.