Norimichi Kojima
Emeritus Professor, The University of Tokyo[Present Position]
Fellow at Toyota Physical and Chemical Research Institute[Research Field]
Physics and Chemistry of Transition-Metal Complexes, Molecular Magnetism[Date of Birth]
October 01, 1949

[Sex] Male [Nationality] Japan[Academic Qualifications]
03/1972 Bachelor of Science, Kyoto University
03/1974 Master of Science, Kyoto University
03/1978 Doctor of Science, Kyoto University
Thesis: Spectroscopic Study on Two-dimensional Antiferromagnets]Professional Career]
12/1977 - 11/1978 Post Doctoral Research Fellow in Broadcasting Science ResearchLaboratory, Japan Broadcasting Corporation (NHK)04/1979 – 03/1981 Part-time Lecturer, College of General Education, Kyoto University
04/1981 – 03/1984 Lecturer, Kobe-Tokiwa College
04/1984 – 02/1992 Research Associate, Faculty of Science, Kyoto University
03/1992 – 04/1994 Associate Professor, Faculty of Science, Kyoto University
05/1994 – 03/1996 Professor, Faculty of Arts and Sciences, The University of Tokyo
04/1996 – 03/2015 Professor, Graduate School of Arts and Sciences, The Universityof Tokyo
04/2005 – 02/2007 Vice-Dean, Graduate School of Arts and Sciences/College of Arts
and Sciences, The University of Tokyo
02/2007 – 02/2009 Dean, Graduate School of Arts and Sciences/College of Arts andSciences, The University of Tokyo
04/2009 – 03/2010 Executive Managing Director, The University of Tokyo
04/2009 – 03/2011 Vice-President, The University of Tokyo
04/2011 – 03/2012 Director-General, Division of Environmental, Health and Safety(EHS), The University of Tokyo
04/2015 Fellow, Toyota Physical and Chemical Research Institute[Membership]
Chemical Society of Japan, Physical Society of Japan, Japan Society for Molecular
Science, Japan Society of Coordination Chemistry, Japan Mössbauer Spectroscopy
Forum, Society of Muon and Meson Science of Japan

Research Overview
Norimichi Kojima
One of the most attractive research in the field of molecular solids is the investigation ofmulti-functionality induced by the synergetic effect between magnetic, optical ortransport properties. Among various multifunctional materials, assembled transitionmetal complexes are the leading candidates as field-responsive multifunctional materials.
From these viewpoints, we have developed various kinds of assembled transition-metal
complexes and investigated their multifunctional phenomena.

[Study on the magneto-optics of transition-metal compounds](19761995)
In magnetic compounds, various types of elementary excitations (excitons, magnons,phonons, domain-solitons, etc.) exist. The interaction between these elementary
excitations enables them to combine with one another, forming new and more complex
excitations such as exciton-magnon transition (magnon sideband). This interaction has aneffect on the propagation, energy position and shape of the complex excitations. The mostdramatic effect is the existence of the bound states below or above the two-particle
continuum under certain circumstances. We have investigated the behavior of theseelementary excitations in the optical 3d-3d or 4f-4f transition for various magnetic
insulators, which has been reviewed in “Magneto-Optics” ed. S. Sugano and N. Kojima(Springer, 2000).

[Study on the opticalcomplexes](1986-1996)

properties ofplatinum mixed-valence

The inter-valence charge-transfer absorption spectra in the mixed-valence complexes[Pt(en)2][PtI2(en)2](SO4)2∙6H2O and [AuxPt1-xI(en)2]SO4∙3H2O (x = 0.03) have been
investigated at 4.2 K. In these complexes, below the charge transfer absorption edge, aweak absorption band (A band) has been observed for the light polarized parallel to thechain axis. When these complexes were irradiated with the light in the region of thecharge transfer transition from PtII to PtIV, the absorption coefficient of the A band
remarkably increased, which implies that the A band is a photo-induced absorption band.
The photo-induced effect for the A-band in [AuxPt1-xI(en)2]SO4∙3H2O (x = 0.03) is more
intense than that in [Pt(en)2][PtI2(en)2](SO4)2∙6H2O. The A-band suggests the existenceof new excitations such as a soliton-like excitation in the electronic state of the platinum
chains.

N. Matsushita, N. Kojima, T. Ban, I. Tsujikawa, J. Phys. Soc. Jpn. 56, 3808 (1987).

N. Matsushita, N. Kojima, T. Ban, I. Tsujikawa, J. Phys. Soc. Jpn. 56, 3808 (1987).

[Study on the crystal structure and transport phenomena for ternary
copper chalcogenide, A-Cu-X (A = Na, K, Rb, Cs; X = S, Se)](1988-1994)
We have systematically investigated the crystal structure and transport phenomena forternary copper chalcogenides such as K3Cu8S6, KCu4S3, Na3Cu4S4, which have various
kinds of low-dimensional structures and mixed valent compositional ratios. K3Cu8S6,
which is one of such mixed valent low-dimensional copper sulfides, has a layered
structure composed of Cu8S6 sheets separated by potassium ions. Each CusS6 sheet iscomposed of the Cu4S4 chains seen in Na3Cu4S4 and the networks of edge-shared CuS4
tetrahedrons seen in KCu4S3, etc. In the case of K3Cu8S6, two phase transitions areobserved at T1 (153 K) and at T2 (55 K). The resistivity is metallic above T1, while nonmetallic between T1 and T2, in which an incommensurate superstructure (0, (1-δ)/2, 0)
appears. The behavior of resistivity between T1 and T2 is a typical CDW system, while
the intensity of superstructure shows an anomalous oscillation as a function oftemperature. On further cooling, the resistivity decreases drastically at T2. Below T2, theresistivity becomes metallic again, and the incommensurate superstructure disappears but
another commensurate superstructure (1/2, 1/2, 0) instead appears. A possible explanationof the T2 transition is a lock-in transition of the CDW.

H. Sato, E. Igaki, T. Nakamura, T. Ban, N. Kojima, Solid State Commun. 71, 793 (1989) , H. Sato,
N. Kojima, K. Suzuki, T. Enoki, J. Phys. Soc. Jpn. 62, 647 (1993), H. Sato, N. Kojima, S.
Kagoshima, J. Phys. Soc. Jpn. 62, 2051 (1993).

[Study on the pressure-induced and photo-induced Au valencetransition of gold mixed-valence complexes, M2AuIAuIIIX6](1995-2012)
Halogen-bridged gold mixed-valence complexes, M2[AuIX2][AuIIIX4] (M= K, Rb, Cs;
X= Cl, Br, and I) are typical examples for the mixed-valence complexes belonging to theclass II, in which strong inter-valence charge transfer (IVCT) bands appear in visible
region. Their characteristic properties of crystal structure and mixed valence state arequite similar to those of BaBiO3, which is the parent compound of the superconductors,
Ba1-xKBiO3 and BaBi1-xPbO3. M2[AuIX2][AuIIIX4] (M= K, Rb, Cs; X= Cl, Br, and I)
undergo the pressure induced valence transition from the mixed valence state of AuI ,III to
the single valence state of AuII, which is coupled with a structural phase transition. In thecase of Cs2[AuIX2][AuIIIX4] (X = Cl, Br, and I), the Au valence transition takes place at
11-12, 9, and 5.5 GPa, respectively. In the pressure region below the Au valence transition,these complexes show a metallic behavior due to the valence fluctuation of the AuI and
AuIII states. The metallic cubic phase appearing commonly for these complexes underhigh pressure and high temperature can be obtained as a metastable state even at ambientpressure and room temperature. Moreover, we have discovered a photo-induced Au
valence transition for Cs2[AuIBr2][AuIIIBr4].

We have succeeded in synthesizing nine kinds of hetero-halogen bridged gold mixedvalence complexes having perovskite-type structure, Cs2[AuIX2][AuIIIY4](X, Y = Cl, Br,
and I; X ≠ Y), in organic solvent, and obtained their single crystals. Metallic golden color
is attributed to the IVCT transition from the AuI site to the AuIII site.
N. Kojima, H. Kitagawa, J. Chem. Soc. Dalton Trans., 327 (1994), N. Kojima, Bull. Chem. Soc.
Jpn., 73, 1445 (2000), N. Kojima, K. Ikeda, Y. Kobayashi, M. Seto, Mössbauer Effect Reference

and Data Journal, 36, 57 (2013).

Figure: Pressure and temperature induced metallic phase and the existence of metastable
metallic phase of Cs2[AuII2][AuIIII4]. P-T phase diagram of Cs2[AuII2][AuIIII4].
N. Kojima, H. Kitagawa, T. Ban, F. Amita, M. Nakahara, Solid State Commun. 73, 743 (1990), N.
Kojima, M. Hasegawa, H. Kitagawa, T. Kikegawa, O. Shimomura, J. Am. Chem. Soc. 116,
11368 (1994).
.

S.S. Hafner, N. Kojima, J. Stanek, Li Zhang, Phys. Lett. A, 192, 384 (1994).

X.J. Liu, Y. Moritomo, A. Nakamura, N. Kojima, J. Chem. Phys., 110, 9174 (1999).

We have found a photo-induced phase transition (PIPT) for Cs2Au2Br6 from the mixedvalence state of AuI, III to the single-valence state of AuII in the pressure region from 6.4
to 6.8 GPa. The PIPT shows a distinct threshold behavior against the photon density as
well as the shots number, which has been interpreted in terms of the critical nucleation of
the photo-injected AuII clusters.

X.J. Liu, Y. Moritomo, M. Ichida, A. Nakamura, N. Kojima, Phys. Rev. B 61, 20 (2000), N.
Kojima, Bull. Chem. Soc. Jpn., 73, 1445 (2000).

[Study on the charge transfer phase transition and ferromagnetism for
Mixed-Valence Iron Complexes](2000-2018)
Assembled organic-inorganic hybrid system has a possibility to exhibit multifunctional
properties as a whole system through the interaction between individual components.
From this viewpoint, we have developed a ferromagnetic organic-inorganic hybrid system,
A[FeIIFeIII(dto)3] (A = (n-CnH2n+1)4N, spiropyran; dto = C2O2S2), and investigated theirmultifunctional properties coupled with spin, charge and photon. In (nCnH2n+1)4N[FeIIFeIII(dto)3], a charge transfer phase transition (CTPT) takes place at 122.4
K and 142.8 K for n = 3 and 4, respectively, where a thermally induced charge transfer
occurs reversibly between the FeII and FeIII sites. The CTPT and the ferromagnetic phasetransition strongly depend on the honeycomb ring size in [FeIIFeIII(dto)3]∞. The increaseof cation size expands the honeycomb ring, which stabilizes and destabilizes the HTP
with FeII (t2g4eg2: S = 2) and FeIII (t2g5: S = 1/2) and LTP with FeII (t2g6: S = 0) and FeIII(t2g3eg2: S = 5/2), respectively. In order to control the ferromagnetic properties and the

CTPT by means of photo-irradiation, we synthesized a photo-responsive organicinorganic hybrid system, (SP-R)[FeIIFeIII(dto)3] (SP = spiropyran; R = CH3 (Me), C2H5(Et), C3H7 (Pr)), and found that this system undergoes the photo-isomerization of SP-R
reversibly in solid state, and the photo-isomerization of SP-Me by UV light irradiation
partially induces the CTPT from LTP to HTP on the two-dimensional [FeIIFeIII(dto)3]
layer and the change of TC from 5 K to 22 K.

Figure: Haneycomb structure of [FeIIFeIII(dto)3]∞ and the schematic representation of chargetransfer phase transition for (CnH2n+1)4N[FeIIFeIII(dto)3] (dto = C2O2S2)
N. Kojima, W. Aoki, M. Itoi, Y. Ono, M. Seto, Y. Kobayashi and Yu. Maeda, Solid State
Commun., 120, 165-170 (2001), T. Nakamoto, Y. Miyazaki, M. Itoi, Y. Ono, N. Kojima, M.
Sorai, Angew. Chem.Int. Ed., 40, 4716-4719 (2001).

Figure: 57Fe Mössbauer spectra for (n-CnH2n+1)4N[FeIIFeIII(dto)3] (n = 3-6) at 200 K, 77
K and 4 K.
The assignment of the 57Fe Mössbauer spectra were confirmed by the measurementsfor 57Fe-enriched samples, (n-C3H7)4N[57FeIIFeIII(dto)3] and (n-C3H7)4N[FeII 57FeIII(dto)3].
At 200 K, the line profiles of all the complexes are quite similar to each other, where twoquadrupole doublets (A and B) mainly exist. The wider doublet (B) and the narrower
doublet (A) are assigned to the FeII (S = 2) site coordinated by six O atoms, and the FeIII
site coordinated by six S atoms. In the cases of n = 3 and 4, with decreasing temperaturefrom 200 K to 77 K, the 57Fe Mössbauer spectra corresponding to the HTP decrease by
about 80%. Instead of these spectra, two doublets (C and D) appear. At 4 K, a central
strong doublet (C) and a sextet (D) divided from –8 to +8 mm s-1 with a large hyperfine
field (Hint = ~450 kOe) are observed. The former can be assigned to the diamagnetic stateof FeII (S = 0) and the latter is typical of the magnetically ordered state of FeIII (S = 5/2).
From the analysis of 57Fe Mössbauer spectra for (n-CnH2n+1)4N[FeIIFeIII(dto)3], it isobvious that the charge transfer between the FeII and FeIII sites takes place between 200
K and 77 K for n = 3 and 4. The 57Fe Mössbauer spectra in the ferromagnetic phases forn = 5 and 6 are completely different from those for n = 3 and 4. In the cases of n = 5 and6, the CTPT does not take place, so that the spectra at 4 K can be assigned to the FeII (S= 2) and FeIII (S = 1/2) sites in the magnetically ordered phase.
N. Kojima, N. Kida, A. Okazawa, M. Enomoto, Mössbauer Effect Reference and Data Journal,
35, 154 (2012), N. Kojima, M. Itoi, Y. Miyazaki, Current Inorg. Chem., 4, 85 (2014).

M. Itoi, Y. Ono, N. Kojima, K. Kato, K. Osaka, M. Takata, Eur. J. Inorg. Chem., 1198 (2006).

Figure: Molecular design of (SP)[FeIIFeIII(dto)3] (SP = spiropyran) toward photo-induced
charge transfer phase transition by means of photo-isomerization of photochromic
molecule.

Figure: Temperature dependence of the magnetization for (SP-Me)[FeIIFeIII(dto)3] before
and after the UV light irradiation (350 nm with half width of 10 nm, 40 mW cm-2) for 4
h at room temperature. FCM: field cooled magnetization, RM: remnant magnetization,
ZFCM: zero-field cooled magnetization.
N. Kida, M. Hikita, I. Kashima, M. Okubo, M. Itoi, M. Enomoto, K. Kato, M. Takata, N. Kojima,
J. Am. Chem. Soc., 131, 212 (2009).

Figure: 57Fe Mössbauer spectra of (SP-Me)[FeIIFeIII(dto)3] at 6 K before and after UVlight Irradiation (350 nm with half width of 10 nm, 40 mW cm-2) for 3 h at 300 K.

N. Kida, M. Hikita, I. Kashima, M. Enomoto, M. Itoi, N. Kojima, Polyhedron, 28, 1694 (2009).

N. Kida, M. Hikita, I. Kashima, M. Okubo, M. Itoi, M. Enomoto, K. Kato, M. Takata, N. Kojima,
J. Am. Chem. Soc., 131, 212-220 (2009).

[Dynamical Behavior of the Charge Transfer Phase Transition by meansof muon spin spectroscopy](2007-2010)
Muon is a very useful elemental particle for sensing the magnitude, distribution andfluctuation of internal field. Therefore, the muon spin spectroscopy (μSR) has been
applied to the study of magnetic phase transitions, various kinds of spin frustrations,superconducting phenomena and so forth. We have applied the μSR technique to an ironmixed-valence system, (n-CnH2n+1)4N[FeIIFeIII(dto)3] in order to investigate thedynamical behavior of the charge transfer phase transition (CTPT), and the hopping rateof electrons between FeII and FeIII sites at the CTPT was revealed for the first time by the
analysis of μSR under longitudinal magnetic field.

Figure: Schematic representation of muon spectroscopy. NF(t) and NB(t) are the total
muon events of the forward and backward counters aligned in the beam line, respectively.
Temperature and longitudinal-field dependence of the dynamic muon spin depolarization
rate, λ0, at around CTPT for (n-C3H7)4N[FeIIFeIII(dto)3]. Schematic representation of thevalence fluctuation between the FeII and FeIII sites at the CTPT.
N. Kida, M. Enomoton, I. Watanabe, T. Suzuki and N. Kojima, Phys. Rev. B 77, 144427 (2008),
M. Enomoto, I. Watanabe, N. Kojima, Current Inorg. Chem., 6, 49 (2016).

[Control of ferromagnetism of Co4(OH)7(DAE)0.5∙3H2O by means ofphoto-isomerization of intercalated diaryletnene] (2005-2016)
Novel cobalt-based organic-inorganic compounds were prepared by anion exchange
reaction, using the photochromic diarylethene anion (DAE). From the magnetic
susceptibility measurements, the ferromagnetic transition temperature ofCo4(OH)7(DAE)0.5∙3H2O changes from 9 K to 20 K with substitution of the intercalatedanion from the open-form of DAE (1a) to the closed-form of DAE (1b). Therefore, thechange of the Curie temperatures between Co4(OH)7(DAE-open form)0.5∙3H2O (2a) andCo4(OH)7(DAE-closed form)0.5∙3H2O (2b) can be attributed to the change of the πelectron system in the DAE molecule. Moreover, the appearance of shoulder in the ACmagnetic susceptibility for Co4(OH)7(DAE-open form)0.5∙3H2O after the irradiation of
UV implies that the ferromagnetism of this system can be controlled by photo-irradiation.
In the temperature range between 9 K and 20 K, 2a is placed above the ferromagnetictransition temperature, while 2b is in below the ferromagnetic temperature, when thephotoisomerization occurs in this temperature region, we can select the magnetism as theparamagnetic phase with 2a or the ferromagnetic phase with 2b by selecting the
wavelength of irradiated light. This compound may be developed to realize a novel optical
writing medium at low temperature.

Figure: Synthesis of Co4(OH)7(DAE)0.5∙3H2O by means of anion exchangeM. Okubo, M. Enomoto, N. Kojima, Sold State Commun., 134, 777 (2005), H. Shimizu, M. Okubo,

A. Nakamoto, M. Enomoto, N. Kojima, Inorg. Chem., 45, 10240 (2006).

[Study on the dynamical spin equilibrium and its induced successive
magnetic phase transition](2010-2018)
In general, the FeIII site coordinated by six S atoms is in the low-spin (LS) state, while
the FeIII site coordinated by six O atoms is in the high-spin (HS) state. Therefore, it isexpected that the spin state of FeIII coordinated by three S atoms and three O atoms issituated in the spin-crossover region. Actually, the spin equilibrium in which the highspin (HS) state and the low-spin (LS) state exchange have been confirmed formononuclear FeIII complexes consisting of FeIIIO3S3. However, the rapid spin equilibrium
phenomenon has not yet been observed for assembled metal complex systems. From thisviewpoint, in order to build an assembled metal complex system including FeIIIO3S3 site,
we have synthesized Ph4P[ZnIIFeIII(mto)3] (mto = monothiooxalato) consisting of
FeIIIO3S3 and ZnIIO6 octahedra and investigated the spin state of the FeIIIO3S3 site.
Ph4P[ZnIIFeIII(mto)3] has a two-dimensional honeycomb network structure. The ESR and
57
Fe Mössbauer spectra revealed that the rapid spin equilibrium in which the high-spin(HS) state and the low-spin (LS) state exchange in the time scale of 10−10 < τ < 10−7 soccurs at the FeIIIO3S3 site, which is the first report for an assembled metal complex
system.

K. Kagesawa, A. Okazawa, M. Enomoto, N. Kojima, Chem. Lett. 39, 872 (2010).

In the case of assembled transition metal complexes whose spin states are situated in
the spin-crossover region, concerted phenomena coupled with spin-crossoverphenomenon and magnetic phase transitions are expected. From this viewpoint, we havesynthesized a mto (= C2O3S) bridged hetero-metal complex system, (C6H5)4P[MnIIFeIII(mto)3] consisting of FeIIIO3S3 and MnIIO6 octahedra. The molar magnetic
susceptibility (χM) as a function of temperature has a broad maximum, typical characterof 2D Heisenberg-type antiferromagnet, around 50 K, and shows a steep increase below
30 K with a hump around 23 K, where both of the real (χ’) and imaginary (χ”) parts in
AC magnetic susceptibility exhibit steep peaks indicating a magnetic phase transition.
The field cooled magnetization shows a rapid increase below 30 K, and almost saturares
below 23 K. At 30 K, the remnant magnetization and the magnetic hysteresis loop
disappear. Therefore, it is obvious that (C6H5)4P[MnIIFeIII(mto)3] undergoes two
successive magnetic phase transitions at 30 K and 23 K. The 57Fe Mössbauer
spectroscopy for (C6H5)4P[MnIIFeIII(mto)3] implies that the spin state at the FeIII site isstill paramagnetic even at 24 K. At 23 K, both of the MnII and FeIII spins are eventuallyordered. It is considered that the successive magnetic phase transitions in (C6H5)4P[MnIIFeIII(mto)3] are induced by the rapid spin equilibrium at the FeIII site.

Figure: Successive magnetic phase transitions induced by the rapid spin equilibrium of
FeIIIO3S3 site for (C6H5)4P[MnIIFeIII(mto)3].

[Control of spin crossover phenomena by means of functional counterions[(2005-2018)
The spin-crossover (SCO) phenomenon between a high-spin and a low-spinstate has attracted much attention in the field of materials science. Among thevarious kinds of SCO complexes, the triazole-bridged iron(II) polymeric chain
system, [Fe(II)(R-trz)3]X2·xH2O (where trz is triazole and X is the anion),
exhibiting the SCO phenomenon with thermal hysteresis around room
temperature, has been extensively studied from the viewpoint of molecularmemory and molecular devices. In connection with this system, we havecontrolled the SCO phenomenon according to the characteristic properties ofcounter ions. In the case of X = CnH2n+1SO3–, the spin transition temperature (T1/2)
increases with increasing the length (n) of the alkyl chain of the counter ion andsaturates above n = 5, which is attributed to the increase in the intermolecularinteraction of the alkyl chains of CnH2n+1SO3–, called the fastener effect. The
hysteresis width of T1/2 decreases with increasing n, showing the even-odd effect.
In the cases where X is toluenesulfonate (tos: CH3C6H4SO3–) andaminobenzenesulfonate (abs: NH2C6H4SO3–), T1/2 and its hysteresis width vary
drastically with the positional isomersism (ortho-, metha- and para-substitution)of counter ions, which implies the possibility of photoinduced spin transition bymeans of the photoisomerization of counter ions.

Figure: Nearest-neighbor Fe–Fe distance as a function of the alkyl chain length (n) at 35
K, and the correlation between SCO temperature (T1/2) and the nearest neighbor Fe–Fe
for [FeII(NH2-trz)3](CnH2n+1SO3)2·xH2O. Schematic representation of the fastener effecton R(Fe–Fe) and R(Fe–N) for [FeII(NH2-trz)3](CnH2n+1SO3)2·xH2O;
H. Kamebuchi, A. Nakamoto, T. Yokoyama, N. Kojima, Bull. Chem. Soc. Jpn., 88, 419 (2015).
A. Sugahara, H. Kamebuchi, A. Okazawa, M. Enomoto, N. Kojima, Inorganics, 5, 50 (2017).

The Effect of Structural Isomerism of Counter Ions on SCO for the [Fe(II)(R-trz)3]
SystemFigure: Temperature dependence of the magnetic susceptibility multiplied by temperature(χMT) for [Fe(II)(NH2-trz)3](o-, m-, and p-tos)2·xH2O and [Fe(II)(NH2-trz)3](abs)2·2H2O..
The arrows represent the sweeping directions of temperature.
A. Sugahara, H. Kamebuchi, A. Okazawa, M. Enomoto, N. Kojima, Inorganics, 5, 50 (2017).

[Development of multifunctional spin crossover complex film] (20032018)
Transition metal complexes with 3d4–3d7 configurations in octahedral surroundings
have a possibility of spin-crossover transition between low-spin (LS) and high-spin (HS)states. The spin-crossover phenomenon has attracted much attention since the discoveryof the photo-induced spin transition (light induced excited spin state trapping (LIESST))
for [Fe(II)(ptz)6](BF4)2 (ptz = 1-propyltetrazole), and the thermally-induced spintransition with large thermal hysteresis around room temperature for 1,2,4-triazole (= trz)
bridged Fe(II) complexes, [Fe(II)(R-trz)3]A2·nH2O (A = anion). In particular, the triazolebridged polymeric Fe(II) chain system has a possibility of molecular device such as
display and memory at room temperature. In order to realize photo-responsive moleculardevices, the development of transparent spin-crossover film has been desired. From thisviewpoint, we have succeeded in synthesizing a transparent complex film, [Fe(II)(Htrz)3]-Nafion, exhibiting the spin crossover phenomenon around room temperature, inwhich Nafion membrane behaves as counter anion as well as transparent substrate. From
the analysis of Fe K-edge EXAFS spectra, we have proved the existence of onedimensional Fe chain structure, [Fe(H-trz)3]n, in Nafion film, and the LIESST effect at
4.2 K.

A. Nakamoto, Y. Ono, N. Kojima, D. Matsumura, T. Yokoyama, Chem. Lett., 32, 336 (2003),
A. Nakamoto, N. Kojima, X.J. Liu, Y. Moritomo, A. Nakamura, Polyhedron, 24, 2909 (2005).
LIESST effect of the spin crossover complex film, [FeII(H-trz)3]-Nafion,

We have investigated the LIESST effect for the transparent spin crossover complex film,[FeII(H-trz)3]-Nafion, and observed the condensed phase of photo-generated HS
molecules below 35 K. The life time of the photo-generated HS state strongly depends on
the intensity of irradiated light and temperature. Figure shows the relaxation dynamics ofthe photo-generated HS molecules for [FeII(H-trz)3]-Nafion at 4.2K after turning off theexcitation light: (a) P = 37 mW/cm2 and (b) P = 350 mW/cm2. Solid curves are leastsquares-fitting results. Phase diagram of the FeII(Htrz)3]-Nafion against excitation power
density (P) and temperature (T). The hatched region represents the condensed phase of
the photo-excited HS molecules.

X.J. Liu, Y. Moritomo, T. Kawamoto, A. Nakamoto, N. Kojima, Phys. Rev. B, 67, 012102 (2003),
J. Phys. Soc. Jpn., 72, 1615 (2003).

pH-responsive spin-crossover complex film, [FeII(diAMsar)]-Nafion
We have developed pH-responsive spin-crossover FeII complex films, by using
diAMsar (1,8-diaminosarcophagine) as a ligand. Sarcophagine (sar) and its derivatives
are hexadentate cage-type ligands, whose coordination compounds with FeII exhibit the
spin-crossover phenomenon between the high spin state with t2g4eg2 (S = 2) and the low
spin state with t2g6 (S = 0). The spin-transition temperature and the color of[FeII(diAMsar)] in the solution depend on pH (T1/2 = 290 K for pH = 4.5; T1/2 = 370 K for
pH = 8.5) due to the protonation/deprotonation of the terminal amino groups in diAMsar.
[FeII(diAMsar)]-Nafion also has different colors depending on the proton concentration
controlled by buffer solution (pH = 4, 7 and 10), which indicates the spin state of[FeII(diAMsar)]-Nafion is spatiotemporally manipulated by the gradient of proton
concentration derived from applied voltage. In this way, we can visualize the proton flowin Nafion membrane by using the pH-responsive spin-crossover complex as a color
indicator. The development of field responsive spin-crossover complex films will open alarge field of multifunctional molecular devices based on Nafion membrane.

H. Kamebuchi, T. Jo, H. Shimizu, A. Okazawa, M. Enomoto, N. Kojima, Chem. Lett., 40, 888(2011), H. Kamebuchi, M. Enomoto, N. Kojima, “Nafion: Properties, Structure and Applications,”
Ch. 6, (Nova Science Publishers, Inc., 2016),[Study on thiolate-protected Au clusters by means of 197Au Mössbauer
spectroscopy] (2006-2018)
The evolution of geometrical structures of thiolate (SR)-protected gold clusters,
Aun(SR)m, in a n = 10 − 55 size range, was studied by means of 197Au Mössbauer
spectroscopy. Successful analysis of the Au25(SR)18 spectrum, based on the
crystallographically determined structure, enabled us to estimate quantitatively the
numbers of gold atoms coordinated by different numbers (0, 1, and 2) of SR ligands for
all the Aun(SR)m clusters. In Au10(SR)10, all the gold atoms are bonded to SR ligands,
indicating –Au–S(R)– cyclic structures. A catenane structure was proposed for Au10(SR)10.
At n = 15, gold atoms bonded to a single SR ligand appeared, suggesting the formationof small clusters. At n = 25, a single Au atom without the SR ligation appeared, consistent
with the formation of an icosahedral Au13 core protected by six staples, –S(R)–[Au–S(R)–]2. At n = 39, the number of Au atoms without the SR ligation increases from one
to two, and the 197Au Mössbauer spectrum is consistent with the face-fused bi-icosahedral
Au23 core. These results demonstrate that 197Au Mössbauer spectroscopy will provide
detailed information on the structures of thiolate-protected gold clusters whose single
crystals are difficult to make.

K. Ikeda, Y. Kobayashi, Y. Negishi, M. Seto, T. Iwasa, K. Nobusada, T. Tsukuda, N.
Kojima, J. Am. Chem. Soc., 129, 7230 (2007), T. Tsukuda, Y. Negishi, Y. Kobayashi,
N. Kojima, Chem. Lett., 40, 1292 (2011), N. Kojima, Y. Kobayashi, Y. Negishi, M.
Seto, T. Tsukuda, Hyper. Interact., 217, 91 (2013),

[Study on molecular magnetism and single molecule magnet](2005-2018)
Study on the 4f–3d magnetic interaction of [Ln2Cu2] (Ln = lanthanide)
The magnetization measurements and HF-EPR spectroscopy are complementary
methods for the elucidation of the spin structures and energy diagrams for 4f–3d
heteronuclear systems. By using HF-EPR spectroscopy, We have demonstrated thesignificant chemical trend in the plot of J4f–3d against Z for the 4f–3d heteronuclear system,[Ln2Cu2]n (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er). The ferro- and antiferromagnetic 4f–
3d couplings were characterized for the light and heavy lanthanoid derivatives,
respectively. The J4f–3d magnitude monotonically decreases with a decrease of the numberof the 4f spins, and the strongest coupling was observed for the Gd3+ (4f7) derivative.

Figure: Crystal structure of [{Tb(hfac)2(MeOH)}2{Cu(dmg)(Hdmg)}2]n (Hhfac =1,1,1,5,5,5-hexafluoropentane- 2,4-dione; H2dmg = dimethylglyoxime).

Figure: J4f–3d parameters of [Ln2Cu2] in [{Tb(hfac)2(MeOH)}2{Cu(dmg)(Hdmg)}2]n as afunction of the atomic number of Ln ions.

A. Okazawa, K. Fujiwara, R. Watanabe, N. Kojima, S. Yoshii, H. Nojiri, T. Ishida, Polyhedron,30, 3121 (2011).

Study on the single molecular chain magnet of mixed-valence Fe complex,
We have investigated the single molecular chain magnet of mixed-valence Fe complex,[FeII(ClO4)2{FeIII(bpca)2}]ClO4 (Hbpca = bis(2-pyridylcarbonyl)amine) by means of AC
magnetic susceptibility, 57Fe Mössbauer spectroscopy and muon spin spectroscopy. The
relaxation times τ (T) extracted from the AC susceptibility and 57Mössbauer spectra wereused to construct an Arrhenius plot giving an estimated activation energy of 27 K.
Extrapolating the Arrhenius plot, the blocking temperature (τ (TB) ) 100 s) was estimatedas TB = 1.3 K.

Figure: Crystal structure of [FeII(ClO4)2{FeIII(bpca)2}]ClO4 (Hbpca = bis(2pyridylcarbonyl)amine) and the spin allignment of FeII (S = 2)-FeIII (S = 1/2).

Figure: Temperature dependence of 57Fe Mössbauer spectra between 200 K and 3.7 K,(b) AC magnetic susceptibility (χ”) as a function of temperature for [FeII(ClO4)2{FeIII(bpca)2}]ClO4.

T. Kajiwara, M. Nakano, Y. Kaneko, S. Takaishi, T. Ito, M. Yamashita,、H. Nojiri, N. Kojima,
et al, J. Am. Chem. Soc., 127, 10150 (2005), T. Kajiwara, I. Watanabe, Y. Kaneko, S. Takaishi, M.
Enomoto, N. Kojima, M. Yamashita, J. Am. Chem. Soc., 129, 12360 (2007).

3) Study on the single molecule magnet of linear two-coordinate FeII complex
We have investigated the behavior of single molecule magnet of linear two-coordinate
FeII complexs bearing fused-ring bulky Rind groups, FeII(Rind)2, by means of AC
magnetic susceptibility and 57Fe Mössbauer spectroscopy. All of these Fe(II) complexes
adopt an almost linear C–Fe–C arrangement in the crystals (C–Fe–C angles of ca. 174–178°). For Fe(Eind)2, a significant orbital contribution due to the linear two-coordinationof the Fe(II) ion has been determined by the high effective magnetic moment (μeff = 5.82μB) and the extraordinarily large internal hyperfine field (Hn = ca. 140 T) in the 57Fe
Mössbauer spectrum. Variable frequency out-of-phase ac susceptibility data for Fe(Eind)2
demonstrate an effective spin-reversal barrier of Ueff = 51.2 cm–1 associated with thesingle-ion magnet behavior.

Figure: 3d electron configuration of FeII and the Molecular structure of FeII(Eind)2.

Figure: AC magnetic susceptibility (χ”) as a function of AC frequency, and 57Fe
Mössbauer spectra at T = 4.2 K and H = 3.0 T for FeII(Eind)2.
S. Goda, M. Nikai, M. Ito, D. Hashizume, K. Tamao, A. Okazawa, N. Kojima, H. Fueno,
K. Tanaka, Y. Kobayashi, T. Matsuo, Chem. Lett., 45, 634–636 (2016).

Publication list (2018)
Norimichi Kojima
Original papers
1) N. Kojima, T. Ban and I. Tsujikawa, “ Ｍ agnon Sideband in the Quasi Two-Dimensional
Antiferromagnet (C 2 H 5 NH 3 ) 2 MnCl 4 .” J. Phys. Soc. Jpn. 41, 1809-1810 (1976).
2) N. Kojima, T. Ban and I. Tsujikawa, “Temperature Dependence of the Absorption Spectra 6A 1g→ 4A 1g (4G), 4E q (4G) in the Quasi Two-Dimensional Antiferromagnet (C n H 2n ＋
1 NH 3 ) 2 MnCl 4 (n=2, 3).” J. Phys. Soc. Jpn. 44, 919-922 (1978).
3) N. Kojima, T. Ban and I. Tsujikawa, “Magnon Sideband of the 4T 2q (4D) State in the Quasi TwoDimensional Antiferromagnet (C 2 H 5 NH 3 ) 2 MnCl 4 .” J. Phys. Soc. Jpn. 44, 923-929 (1978).
4) N. Kojima, T. Tsushima and I. Tsujikawa, “Optical Investigations of YbCrO 3 . I. Optical Absorption
Spectra of Yb3＋ Ion.” J. Phys. Soc. Jpn. 49, 1449-1455 (1980).
5) N. Kojima, K. Tsushima, S. Kurita and I. Tsujikawa, “Optical Investigations of YbCrO 3 . II.
Metamagnetic Transition in YbCrO 3 .” J. Phys. Soc. Jpn. 49, 1456-1462 (1980).
6) N. Kojima, K. Aoyagi, K Tsushima, I. Tsujikawa and S. Sugano, “Optical Investigations of in
YbCrO 3 . III. Cr3＋ Exciton – Yb3＋ Spin Flip Simultaneous Absorption.” J. Phys. Soc. Jpn. 49,
1463-1468 (1980).
7) N. Kojima, I. Tsujikawa and K. Tsushima, “Field Induced Spin Reorientation in HoCrO 3 .” Ferrites,
769-773 (1980).
8) N. Kojima, T. Ban and I. Tsujikawa, “Exciton Transfer in the Two-Dimensional Antiferromagnet(C 2 H 5 NH 3 ) 2 MnCl 4 .” Int. J. Quantum Chemistry 18, 619-623 (1980).
9) N. Kojima, K. Tsushima, K. Aoyagi and I. Tsujikawa, “Cr3＋ Exciton Accompanied with R3＋ Spin
Flip in Rare-Earth Orthochromite RCrO 3 .” J. Mag. Mag. Materials 31-34, 560-562 (1982).
10) N. Kojima, I Tsujikawa, H. Hori, H. Nishimura and M. Date, “Optical Absorption Spectrum in
YbCrO 3 under High Magnetic Field.” J. Phys. Soc. Jpn. 53, 2875-2878 (1984).
11) N. Kojima, I. Tsujikawa and K. Tsushima, “Optical Investigations of Rare-Earth Orthochromites.
I. TmCrO 3 .” J. Phys. Soc. Jpn. 54, 4794-4803 (1985).
12) N. Kojima, I. Tsujikawa, K. Aoyagi and K. Tsushima, “Optical Investigations of Rare-Earth
Orthochromites. II. RCrO 3 (R=Er, Ho, Dy and Tb).” J. Phys. Soc. Jpn. 54, 4804-4820 (1985).
13) N. Kojima, I. Tsujikawa and K. Tsushima, “Optical Investigations of Rare-Earth Orthochromites.
III. GdCrO 3 and Summary of the R’Band in RCrO 3 .” J. Phys. Soc. Jpn. 54, 4821-4827 (1985).
14) H. Hori, N. Kojima, H. Nishimura, I. Tsujikawa and M. Date, “Optical Spectrum of R’-Band in
Spin Reorientated YbCrO 3 under High Magnetic Field.” J. Phys. Soc. Jpn. 55, 1380-1383 (1986).
15) I. Mogi, T. Okamoto, N. Kojima, T. Ban and I. Tsujikawa, “Exciton-Magnon Transition in the Linear
Chain Compound CsCoCl 3 ·2H 2 O.” J. Phys. Soc. Jpn. 55, 987-992 (1986).
16) I. Mogi, N. Kojima, T. Ban and I. Tsujikawa, “Exciton Transition in the One-Dimensional
Antiferromagnet CsCoCl 3 ·2H 2 O.” J. Phys. Soc. Jpn. 55, 3664-3670 (1986).
17) M. Tanaka, N. Kojima, Y. Ajiro, T. Ban and I. Tsujikawa, “Synthesis and Electrical Conductivity ofa New Family of Pt Mixed Valence Complexes: Pt 6 (NH 3 ) 14 Cl 10 X 4 (X=ClO 4 , BF 4 and PF 6 ).”Synthetic Metals 19, 967-970 (1987).
18) K. Suzuki, N. Kojima, T. Ban and I Tsujikawa, “Synthesis, Transport and SuperconductingProperties of Rare Earth Metal Intercalated Tantalum Disulfide Re x TaS 2 (RE=La, Ce).”
Synthetic Metals 19, 893-896 (1987).
19) S. Kutsumizu, N. Kojima, T. Ban and I. Tsuikawa, “Study of One-Dimensional Metal Complexes:
K[Ni(mnt) 2 ]H 2 O and K[Pt(mnt) 2 ]·H 2 O.” Bull. Chem. Soc. Jpn. 60, 2547-2552 (1987).
20) N. Matsushita, N. Kojima, T. Ban and I. Tsujikawa, “Photo-Induced Absorption Band in OneDimensional Halogen-Bridged Mixed-Valence Platinum Complex: [Pt(en) 2 ][PtI 2 (en) 2 ](SO 4 ) 2 ·6H 2 O and [Au x Pt 1-x I(en) 2 ]SO 4 ·3H 2 O.” J. Phys. Soc. Jpn. 56, 3808-3811 (1987).
21) I. Mogi, N. Kojima, Y. Ajiro, H. Kikuchi, T. Ban and I. Tsujikawa, “Optical Investigation of Soliton
in One-Dimensional Ising-Like Antiferromagnet CsCoCl 3 .” J. Phys. Soc. Jpn. 56, 4592-4597(1987).
22) K. Kojima, J. Matsuda, N. Kojima, T. Ban and I. Tsujikawa, “Optical and ESR Spectra for HighSpin Tetrahedral Complexes of Co (III) and Co (II) in Keggin-Structure Heteropolytungstate.”
Bull. Chem. Soc. Jpn. 60, 3213-3217 (1987).
23) I. Mogi, N. Kojima, T. Ban, I. Tsujikawa and S. Kurita, “Magnon Sideband in the One-Dimensional
Antiferromagnet CsCoCl 3 ·2H 2 O under Magnetic Field I.” Solid State Commun. 61, 327-330(1987).
24) I. Mogi, N. Kojima, I. Tsujikawa, Y. Kanamori, K. Kindo, K. Hazumi and M. Date, “High Field
Magnetization of the One-Dimensional Ising Antiferromagnet CsCoCl 3 ·2H 2 O.” J. Phys. Soc.
Jpn. 56, 2227-2228 (1987).
25) N. Kojima and I. Tsujikawa, “Cr3＋ Exciton Motion in Rare Earth Orthochromite RCrO 3 .” J. Mag.
Soc. Jpn. 11-S1, 45-50 (1987).
26) M. Takeda, G. Kido, Y. Nakagawa, H. Okada, N. Kojima, T. Ban and I. Tsujikawa, “MagnetoAbsorption Spectra of CsFeCl 3 ·2H 2 O up to 220 kOe.” J. Mag. Soc. Jpn. 11-S1, 65-68 (1987).
27) H. Togashi, N. Kojima, T. Ban and I. Tsujikawa, “Field Induced Davydov Splitting in Quasi OneDimensional Antiferromagnets CsMnCl 3 ·2H 2 O and (CH 3 ) 2 NH 2 MnCl 3 ·2H 2 O.” J. Mag. Soc.
Jpn. 11-S1, 69-72 (1987).
28) N. Watanabe, N. Kojima, T. Ban and I. Tsujikawa, “Classification of Optical Absorption Spectra in
2D Antiferromagnet [NH 3 (CH 2 ) n NH 3 ]MnCl 4 (n =2, ,5).” J. Mag. Soc. Jpn. 11-S1, 73-76(1987).
29) H. Okada, N. Kojima, T. Ban and I. Tsujikawa, “Optical Absorption Spectra of One-Dimensional
Antiferromagnet CsFeCl 3 ·2H 2 O.” J. Mag. Soc. Jpn. 11-S1, 77-80 (1987).
30) H. Hori, Y. Yamamoto, N. Kojima, I. Tsujikawa, K. Tsushima and M. Date, “High Magnetic Field
Effects on R- and R’-Spectra in YbCrO 3 .” J. Mag. Soc. Jpn. 11-S1, 141-143 (1987).
31) I. Mogi, N. Kojima, T. Ban, I. Tsuikawa, G. Kido, M. Takeda and Y. Nakagawa, “Exciton and
Magnon Sideband in the One-Dimensional Antiferromagnet CsCoCl 3 ·2H 2 O under High Magnetic
Field.” J. Mag. Soc. Jpn. 11-S1, 145-148 (1987).
32) K. Suzuki, N. Kojima, T. Ban and I. Tsujikawa, “Magnetic and Transport Properties of Ce x TaS 2
and (Ce 2 S 3 ) x TaS 2 .” Jpn. J. Appl. Phys. 26-S3, 1299-1300 (1987).
33) H. Togashi, N. Kojima, T. Ban and I. Tsujikawa, “Field-Induced Davydov Splitting of Excitons in
Quasi-One-Dimensional Antiferromagnet CsMnCl 3 ·2H 2 O.” J. Phys. Soc. Jpn. 57, 353-360(1988).
34) I. Mogi, H. Togashi, N. Kojima, T. Ban and I. Tsujikawa, “Exciton Transfer in the Random
Antiferromagnet CsMn 1-x Co x Cl 3 ·2H 2 O.” J. Phys. Soc. Jpn. 57, 2219-2220 (1988).

35) H. Togashi, N. Kojima, T. Ban and I. Tsujikawa, “Optical Absorption by Mn2＋ Ions in MnM (edta)･
6H 2 O (M=Zn, Cu, Ni, and Co).” Bull. Chem. Soc. Jpn. 61, 1903-1909 (1988).
36) N. Watanabe, N. Kojima, T. Ban and I Tsujikawa, “Optical Absorption Spectra in the Quasi-TwoDimensional Antiferromagnets [NH 3 (CH 2 ) n NH 3 ]MnCl 4 (n=2,3,4,5):I. Experimental.” J. Phys.
C: Solid State Phys. 21, 4795-4808 (1988).
37) N. Watanabe, N. Kojima, T. Ban and I Tsujikawa, “Optical Absorption Spectra in the Quasi-TwoDimensional Antiferromagnets [NH 3 (CH 2 ) n NH 3 ]MnCl 4 (n=2,3,4, 5): II. Theoretical.” J. Phys. C:
Solid State Phys. 21, 4809-4825 (1988).
38) N. Kojima and I. Tsujikawa, “Field Dependence of the Bound State of Cr3＋ Exciton Accompaniedwith Yb3＋ Spin Flip in YbCrO 3 .” J. de Phys. 49-C8, 897-898 (1988).
39) M. Takeda, G. Kido, Y. Nakagawa, H. Okada, N. Kojima and I. Tsujikawa, “Spin Phase Transitionin CsFeCl 3 ･2H 2 O Induced by the Intense Magnetic Field.” J. de Phys. 49-C8, 1461-1462 (1988).
40) M. Takeda, G. Kido, I.Mogi, Y. Nakagawa, H. Okada and N. Kojima, “New Electronic Excitation
at the Boundary of Ferromagnetic and Antiferromagnetic Phases in the One-Dimensional Ising
Antiferromagnet CsFeCl 3 ･2H 2 O.” J. Phys. Soc. Jpn. 58, 3418-3423 (1988).
41) N. Matsushita, N. Kojima, T. Ban and I. Tsujikawa, “Comparison between Optical Properties of
Sulfates and Hydrogen-sulfates in Halogen-Bridged Mixed-Valence Platinum (II, IV) Complexes.”
Bull. Chem. Soc. Jpn. 62, 1785-1790 (1989).
42) S. Kutsumizu, N. Kojima and T. Ban, “XPS Study of Au Bis (mnt) Complexes.” Chem. Lett., 345348 (1989).
43) N. Matsushita, N. Kojima, N. Watanabe and T. Ban, “Three Photo Induced Absorption Bands of
One-Dimensional Halogen-Bridged Mixed-Valence Complex, [Pt(en) 2 ][PtBr 2 (en) 2 ](SO 4 ) 2 ･
6H 2 O.” Solid State Commun. 71, 253-258 (1989).
44) H. Sato, E. Igaki, T. Nakamura, T. Ban and N. Kojima, “Hydrostatic Pressure Effect on the ChargeDensity Wave Transition in the Low-Dimensional Metal K 3 Cu 8 S 6 .” Solid State Commun. 71, 793795 (1989).
45) N. Matsushita, N. Kojima, T. Ban and I. Tsujikawa, “Study of Mixed-Valence State in HalogenBridged Mixed-Valence Platinum (II, IV) Complexes by Temperature Dependence of Intervalence
Charge-Transfer Spectra.” Bull. Chem. Soc. Jpn. 62, 3906-3910 (1989).
46) K. Suzuki, N. Kojima, T. Ban and I. Tsujikawa, “Magnetic and Transport Properties of Ce-Ta-S
Ternary System.” J. Phys. Soc. Jpn. 59, 266-272 (1990).
47) N. Kojima, H. Kitagawa, T. Ban, F. Amita and M. Nakahara, “Semiconductor-to-Metal and Metalto-Metal Transitions in the Three-Dimensional Mixed-Valence Compound Cs 2 Au 2 I 6 under High
Pressures.” Solid State Commun. 73, 743-745 (1990).
48) H. Okada, N. Kojima, T. Ban and I. Tsujikawa, “Optical Absorption Spectra of CsFeCl 3 ･2H 2 O. I.
Temperature Dependence.” Phys. Rev. B 42, 11610-11618 (1990).
49) H. Okada, N. Kojima, T. Ban and I. Tsujikawa, “Optical Absorption Spectra of CsFeCl 3 ･2H 2 O.
II. Magnetic Field Dependence.” Phys. Rev. B 42, 11619-11626 (1990).
50) S. Kutsumizu, N. Kojima, N. Watanabe and T. Ban, “Optical and Magnetic Properties ofK[M{S 2 C 2 (CN) 2 } 2 ]･H 2 O (Where M is Ni, Pt, or Au).” J. Chem. Soc. Dalton Trans., 2287-2292(1990).
51) M. Takeda, I. Mogi, G. Kido, Y. Nakagawa, H. Okada and N. Kojima, “Suppression of Soliton
Excitation by External Field in Quasi-One-Dimensional Ising Antiferromagnet RbFeCl 3 ･2H 2 O.”

J. Mag. Mag. Materials 90-91, 244-246 (1990).
52) N. Kojima, H. Kitagawa, T. Ban, F. Amita and M. Nakahara, “Behavior of the Electrical
Conductivity of the Three-Dimensional Mixed-Valence Compounds Cs 2 Au 2 X 6 (X=Cl, Br, I)
under High Pressures.” Synthetic Metals 42, 2347-2350 (1991).
53) H. Kitagawa, H. Sato, N. Kojima, T. Kikegawa and O. Shimomura, “Structure Analysis of HighPressure Metallic State of the Three-Dimensional Mixed-Valence Compound Cs 2 AuIAuIIII 6 by Xray Diffraction Using SR.” Synthetic Metals 42, 1953-1956 (1991).
54) S. Kutsumizu, N. Kojima and I. Tsujikawa, “Electrical Conduction and Electron Spin ResonanceSudies on the Mixed Crystals of K[Pt 1-x Au x (mnt) 2 ]･H 2 O.” J. Chem. Soc. Dalton Trans., 169172 (1991).
55) H. Kitagawa, H. Sato, N. Kojima, T. Kikegawa and O. Shimomura, “Metallization and Phase
Transitions of the Three-Dimensional Halogen-Bridged Mixed-Valence Complex Cs 2 Au 2 I 6 underHigh Pressure.” Solid State Commun. 78, 989-995 (1991).
56) H. Kitagawa, N. Kojima, N. Matsushita, T. Ban and I. Tsujikawa, “Studies of the Mixed-ValenceStates in Three-Dimensional Halogen-Bridged Mixed-Valence Gold Compounds, Cs 2 AuIAuIIII 6(X=Cl, Br, and I). Part 1. Synthesis, X-Ray, and ESR Studies of CrAu 0.6 Br 2.6 .” J. Chem. Soc.
Dalton Trans., 3115-3119 (1991).
57) H. Kitagawa, N. Kojima and T. Nakajima, “Studies of the Mixed-Valence States in ThreeDimensional Halogen-Bridged Mixed-Valence Gold Compounds, Cs 2 AuIAuIIII 6 (X=Cl, Br, and
I). Part 2. X-Ray Photoelectron Spectroscopic Study of Au Compounds.” J. Chem. Soc. Dalton
Trans., 3121-3125 (1991).
58) H. Kitagawa, N. Kojima and H. Sakai, “Studies of the Mixed-Valence States in Three-Dimensional
Halogen-Bridged Mixed-Valence Gold Compounds, Cs 2 AuIAuIIII 6 (X=Cl, Br, and I). Part
3. 197Au Mössbauer Spectroscopic Study.” J. Chem. Soc. Dalton Trans., 3211-3215 (1991).
59) K. Fukui, N. Kojima, H. Ohya-Nishiguchi and N. Hirota, “Metal-Thiolate Boning Properties:
Single-Crystal ESR, Susceptibility, and Polarized Absorption: Evidence for Strong Interaction in
Tetrakis(thiophenolato)cobaltate (II).” Inorg. Chem. 31, 1338-1344 (1992).
60) I. Mogi, N. Takeda, G. Kido, Y. Nakagawa, H. Okada and N. Kojima, “Magnetic Franck-Condon
Effect in the Magneto-Absorption Spectra of CsFeCl 3 ･2H 2 O.” J. Mag. Mag. Mater. 104-107,
1061-1062 (1992).
61) T. Terashima and N. Kojima, “Synthesis, Transport, and Magnetic Properties of Misfit Layer
Compounds (RES) x NbS 2 (Re = rare earth metal).” Materials Science Forum 91-93, 195-200(1992).
62) N. Kojima, “High Field Magneto-Optics in Rare Earth Orthochromite RCrO 3 -Two Types of Bound
States of Cr3＋ Exciton.” Low Temp. Phys., 18, 59-64 (1992).
63) K. Ito and N. Kojima, “Optical Investigation of Two-Dimensional Triangular Lattice
Antiferromagnets VX 2 (X=Cl, Br and I).” Low Temp. Phys., 18, 141-144 (1992).
64) N. Kojima, S. Maeda, N. Tanaka an N. Matsushita, “Midgap Absorption spectra in Various Kinds
of Halogen-Bridged Mixed-Valence Pt Complexes.” Mol. Cryst. Liq. Cryst. 216, 163-168 (1992).
65) N. Matsushita, K. Toriumi and N. Kojima, “Design of Hydrogen Bond Network in Halogen-Bridged
Mixed-Valence Platinum Complexes by Substitution of Counter Ion.” Mol. Cryst. Liq. Cryst.
216, 196-201 (1992).
66) H. Sato and N. Kojima, “Electronic Properties of Low-Dimensional Ternary Copper Chalcogenides
A-Cu-X (A=Na, K, Rb, Cs; X = S, Se).” Phosphorus, Sulfur, and Silicon 67, 361-366 (1992).

67) T. Terashima and N. Kojima, “Magnetic Properties of (CeS) 1.2 NbS 2 and (CeS) 0.6 NbS 2 .” J. Phys.
Soc. Jpn. 61, 3303-3312 (1992).
68) H. Sato and N. Kojima, “Study on Carriers and Charge-Density Wave Transitions of TwoDimensional Metals (K 1-x Rb x ) 3 Cu 8 S 6 , K 3 Cu 8 (S 1-x Se x ) 6 and Rb 3 Cu 8 (S 1-x Se x ) 6 .” Synthetic Metals
56, 2731-2736 (1993).
69) H. Kitagawa, N. Kojima, H. Takahashi and N. Mori, “Electrical Conductivity and its Anisotropy of
the Mixed-Valence Compound Cs 2 Au 2 I 6 under High Pressure and Low Temperature.” Synthetic
Metals 56, 1726-1729 (1993).
70) N. Kojima, A. Tanaka, H. Sato, H. Kitagawa, T. Kikegawa and O. Shimomura, “Phase Diagram of
the Three-Dimensional Halogen-Bridged Mixed-Valence Compounds M 2 Au 2 X 6 (M=Rb, Cs;
X=Cl, Br, I) under High Pressure.” Jpn. J. Appl. Phys. 32-1, 51-53 (1993).
71) N. Kojima, H. Kitagawa, H. Sakai an Yu. Maeda, “197Au Mossbauer Spectroscopy of the Cubic
Phase in the Halogen-Bridged Mixed-Valence Complex Cs 2 Au 2 I 6 .” Nuclear Instruments andMethods in Physics Research B 76, 321-322 (1993).
72) N. Kojima, A. Tanaka, H. Sakai and Yu. Maeda, “197Au Mossbauer Spectroscopic Study on theThree Dimensional Halogen-Bridged Mixed-Valence Complexes M 2 Au 2 X 6 (M=Rb, Cs; X=Br, I).”
Nuclear Instruments and Methods in Physics Research B 76, 366-367 (1993).
73) N. Kojima, M. Kawarazaki, I. Mogi, M. Takeda, G. Kido and Y. Nakagawa, “Bound State of an
Exciton-Magnon System under High Magnetic Fields I. MnF 2 .” Phys. Rev. B 47, 15086-15090(1993).
74) N. Kojima, “Bound State of an Exciton-Magnon System under High Magnetic Fields II. YbCrO 3 .”Phys. Rev. B 47, 15091-15096 (1993).
75) T. Terashima, N. Kojima, K. Suzuki and T. Enoki, “Magnetic Specific Heat of the Incommensurate
Layer Compound (CeS) 1.2 NbS 2 .” Solid State Commun. 84, 963-966 (1993).
76) H. Sato, N. Kojima, K. Suzuki and T. Enoki, “Effects of Alkali Substitution and Pressure on theCharge-Density Wave Transitions of Two-Dimensional Metals K 3 Cu 8 S 6 and Rb 3 Cu 8 S 6 .” J. Phys.
Soc. Jpn. 62, 647-658 (1993).
77) H. Sato, N. Kojima and S. Kagoshima, “Structural Phase Transitions of the Quasi Two-Demensional
Metal (K 1-x Rb x ) 3 Cu 8 S 6 : X-ray Scattering Studies.” J. Phys. Soc. Jpn. 62, 2051-2061 (1993).
78) T. Terashima, N. Kojima, H. Kitagawa, H. Okamoto and T. Mitani, “Optical Reflectivity Spectra ofIncommensurate Layer Compounds (CeS) 1.2 NbS 2 and (CeS) 0.6 NbS 2 .” J. Phys. Soc. Jpn. 62,
2166-2173 (1993).
79) N. Kojima, K. Ito, I. Mogi, M. Takeda, G. Kido, Y. Nakagawa, M. Sakai, N. Kuroda and Y. Nishina,“Optical Investigation of the Magnetic Excitation in Two-Dimensional Triangular Lattice
Antiferromagnets.” J. Phys. Soc. Jpn. 62, 4137-4145 (1993).
80) M. Hangyo, T. Nishio, S. Nakashima, Y. Ohno, T. Terashima and N. Kojima, “Raman and Infrared
Spectra of Misfit Layer Compounds MNbS 3 (M=Sn, Pb, La, Ce).” Jpn. J. Appl. Phys. 32-3, 581583 (1993).
81) T. Terashima and N. Kojima, “Electrical Transport Properties of Incommensurate Layer
Compounds (RES) x NbS 2 (RE = Rare-Earth Metals; x = 1.2, 0.6).” J. Phys. Soc. Jpn. 63, 658-673(1994).
82) N. Kojima and H. Kitagawa, “Optical Investigation of the Intervalence Charge-Transfer Interactionin the Three-Dimensional Au Mixed-Valence Compounds Cs 2 Au 2 X 6 (X=Cl, Br and I).” J. Chem.
Soc. Dalton Trans., 327-331 (1994).

83) N. Kojima, M. Hasegawa, H. Kitagawa, T. Kikegawa and O. Shimomura, “P-T Phase Diagram andGold Valence State of the Perovskite-Type Mixed-Valence Compounds Cs 2 Au 2 X 6 (X=Cl, Br, andI) under High Pressures.” J. Am. Chem. Soc. 116, 11368-11374 (1994).
84) S. S. Hafner, N. Kojima, J. Stanek and Li Zhang, “Divalent Gold in Perovskite Type CsAuI 3 .”Phys. Lett. A 192, 385-388 (1994).
85) M. Hangyo. K. Kisoda, T. Nishio, S. Nakashima, T. Terashima and N. Kojima, “Staging andInterlayer Interaction in the Misfit-Layer Compounds (RS) n NbS 2 (R=La, Ce; n=0.6, 1.2) Studied
by Raman and Infrared Spectroscopies.” Phys. Rev. B 50, 12033-12043 (1994).
86) H. Ito, M. Kubota, Y. V. Sushko, N. Kojima, G. Saito and T. Ishiguro, “Temperature-Pressure Phase
Diagrams of Hydrogenated and Deuterated κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Cl.”
Synthetic
Metals 70, 925-926 (1995).
87) G. Saito, K. Yoshida, M. Shibata, H. Yamochi, N. Kojima, M. Kusunoki and K. Sakaguchi,“Structural and Physical Properties of Charge Transfer Complexes with [M(dto) 2 ] Anions (M=Ni,
Pt, Cu, Pd. dto: Dithiooxalate).” Synthetic Metals 70, 1205-1208 (1995).
88) N. Kojima, H. Okada, M. Kawarazaki, I. Mogi, M. Takeda, G. Kido, Y. Nakagawa and K. Tsushima,“Optical Investigations of YbCrO 3 under High Magnetic Fields I. Yb3+ Absorption Spectra.” J.
Phys. Soc. Jpn. 64, 3082-3089 (1995).
89) N. Kojima, H. Okada, M. Kawarazaki, I. Mogi, M. Takeda, G. Kido, Y. Nakagawa and K. Tsushima,“Optical Investigations of YbCrO 3 under High Magnetic Fields II. Cr3+-Yb3+ Two-Exciton
Absorption.” J. Phys. Soc. Jpn. 64, 3090-3096 (1995).
90) N. Kojima, I. Mogi and G. Kido, “High-Field Magneto-Optics of MnF 2 and YbCrO 3 .” Physica B
216, 336-337 (1996).
91) K. Kisoda, M. Hangyo, S. Nakashima, T. Terashima and N. Kojima, “Charge Transfer and Phononsin Misfit Layer Compounds (RS) x NbS 2 (R = rare earth; x≒1.2).” Physica B 219&220, 565-567(1996).
92) M. Kubota, G. Saito, H. Ito, T. Ishiguro and N. Kojima, “Magnetism of the Organic Superconductor
κ-(BEDT-TTF) 2 Cu[N(CN) 2 ]Cl.” Mol. Cryst. Liq. Cryst. 284, 367-377 (1996).
93) N. Kojima, H. Sakai, M. Seto, S. Kitao and Yu. Maeda, “129I Mossbauer Spectroscopy of Gold
Mixed-Valence Compound Cs 2 Au 2 I 6 .” Societa Italiana di Fisica 50, 47-50 (1996).
94) N. Kojima, M. Seto and Yu. Maeda, “Single Crystal 197Au Mossbauer Spectroscopy of Gold MixedValence Compound Cs 2 Au 2 I 6 .” Societa Italiana di Fisica 50, 43-46 (1996).
95) N. Matsushita, A. Takano and N. Kojima, “Phase Transition and Generation Efficiency of Mismatchof Valence-Alternation in the Neutral MX Chain System. [PtX 2 (en)][PtX 4 (en)] (X=Cl, Br, I).”
Mol. Cryst. Liq. Cryst., 285, 317-322 (1996).
96) N. Kojima, “Structural Phase Transition and Au Valence State of the Perovskite-type Au MixedValence Compounds M 2 Au 2 X 6 (M=Rb, Cs; X=Cl, Br, I) under High Pressure.” Mol. Cryst. Liq.
Cryst., 285, 295-302 (1996).
97) T. Komatsu, N. Kojima and G. Saito, “Magnetic Properties of an Organic Spin-Ladder Compound(BEDT-TTF)Zn(SCN) 3 .” Solid State Commun., 10, 519-523 (1997).
98) N. Matsushita, H. Kitagawa and N. Kojima, “Three-Dimensional Iodo-Bridged Mixed-ValenceGold(I,III) Compound, Cs 2 AuIAuIIII 6 .” Acta Cryst.C, 53, 663-666 (1997).
99) T. Komatsu, N. Kojima and G. Saito, “Ambient-Pressure Superconductivity of κ’-(BEDT-TTF) 2
Cu 2 (CN) 3 Realized by a Carrier- Doping into a Mott-Insulating State.” Synthetic Metals, 85, 1519-

1520 (1997).
100) N. Kojima, F. Fukuhara, H. Kitagawa, H. Takahashi and N. Mori, “Metallic Bipolaron Phase and
Its Pre-entrant Phenomenon in the Au Mixed-Valence Compounds Cs 2 Au 2 X 6 (X=Cl, I) under High
Pressure.” Synthetic Metals. 86, 2175-2176 (1997).
101) A. Gohsh, N. Kimura, S. Ishimaru, R. Ikeda, A. Takano and N. Kojima, “Solid State 1H NMR in
One Dimensional Neutral Complex: [PtCl 2 (en)][PtCl 4 (en)].” Solid State Commun., 104, 469-472(1997).
102)A. Ishikawa, M. Kurasawa, S. Kitahara, A. Sasane, N. Kojima and R. Ikeda, “35Cl NQR Study on
Cs 2 [AuICl 2 ] [AuIIICl 4 ].” Z. Naturforsch., 53a, 590-594 (1998).
103) T. Hashimoto, N. Matsushita, Y. Murakami, N. Kojima, K. Yoshida, H. Tagawa, M. Dokiya and T.
Kikegawa, “Pressure-induced Structural Phase Transition of LaCrO 3 .” Solid State Commun., 108,691-694 (1998).
104) N. Matsushita, H. Ahsbahs, S.S. Hafner and N. Kojima, “Crystal Structure of Mixed-Valence Gold
Compound, Cs 2 AuIAuIIICl 6 up to 18 GPa.” Rev. High Pressure Sci. Technol., 17, 329-331 (1998).
105) T. Yokoyama, Y. Murakami, M. Kiguchi, T. Komatsu and N. Kojima, “Spin-crossover Phase
Transition of a Chain Fe(II) Complex Studied by X-Ray-Absorption Fine-Structure Spectroscopy.”
Phys. Rev. B 58, 14238-14244 (1998).
106) X.J. Liu, K. Matsuda, Y. Moritomo, A. Nakamura and N. Kojima, “Electronic Structure of the Gold
Complexes Cs 2 Au 2 X 6 (X=I, Br, and Cl).” Phys. Rev. B 59, 7925-7930 (1999).
107) X.J. Liu, Y. Moritomo, A. Nakamura and N. Kojima, “Pressure Induced Phase Transition in MixedValence Gold Complexes Cs 2 Au 2 X 6 (X=Cl and Br).” J. Chem. Phys., 110, 9174-9178 (1999).
108) T. Komatsu, N. Kojima and G. Saito, “A Weakly Coupled Molecular Spin-Ladder (BEDTTTF)Zn(SCN) 3 .“ Synth. Metals, 103, 1923-1924 (1999).
109) N. Kojima, Y. Murakami, T. Komatsu and T. Yokoyama, “EXAFS Study on the Spin-Crossover
System, [Fe(4-NH 2 trz) 3 ](R-SO 3 ) 2. “ Synth. Metals, 103, 2154 (1999).
110) Y. Murakami, T. Komatsu and N. Kojima, “Control of Tc and Spin Bistability in the Spin-Crossover
System,[Fe(4-NH 2 trz) 3 ](R-SO 3 ) 2 .” Synth. Metals, 103, 2157-2158 (1999).
111) A. Takano, T. Komatsu, N. Matsushita and N. Kojima, “Photo-Induced and Doping Effects on the
Non-linear Excitation in [PtX 2 (en)][PtX 4 (en)](X=Cl, Br, I).” Synth. Metals, 103, 153 (1999).
112) X.J. Liu, Y. Moritomo, A. Nakamura and N. Kojima, “Broad Raman Band in the Single-ValenceState of Cs 2 Au 2 X 6 (X= Cl and Br).” J. Phys. Soc. Jpn., 68, 3134-3137 (1999).
113) N. Kojima, “Gold Valence Transition and Phase Diagram in the Mixed-Valence Complexes,M 2[AuIX 2 ] [AuIIIX 4 ] (M= Rb, Cs; X= Cl, Br, and I).” Bull. Chem. Soc. Jpn., 73, 1445-1460 (2000).
114) N. Kojima and N. Matsushita, “P-T Phase Diagram and Au Valence State of the Perovskite-type Au
Mixed-Valence Complexes, M 2 [AuIX 2 ][AuIIIX 4 ](M= K, Rb, Cs; X= Cl, Br, I).” Coord. Chem. Rev.,
198, 251-263 (2000).
115) X.J. Liu, Y. Moritomo, A. Nakamura, S. Matsuba and N. Kojima, “Pressure-Induced Phase
Transition in Quasi-1D Mixed-Valence Gold Complexes.” J. Phys. Soc. Jpn., 67, 3158-3161 (2000).
116) N. Matsuba, N. Kojima, T. Komatsu, M. Seto, Y. Kobayashi and Yu. Maeda, “Studies of MixedValenceStatesin
One-Dimensional
Halogen-Bridged
Gold
Compounds[AuIX(DBS)][AuIIIX 3 (DBS)](X= Cl, Br, I; DBS= dibenzylsulfide).” Mol. Cryst. Liq. Cryst., 343,
169-174 (2000).
117) S. Toyazaki, Y. Murakami, T. Komatsu, N. Kojima and T. Yokoyama, “Study on the Spin-CrossoverSystem for [Fe(4-NH 2 trz) 3 ](p-CH 3 C 6 H 4 SO 3 ) 2 nH 2 O.” Mol. Cryst. Liq. Cryst., 343, 175-180(2000).
118) T. Komatsu and N. Kojima, “Molecular Orbital Calculation on the Neutral Mixed-Valent Platinum
Complex, [PtIICl 2 (en)] [PtIVCl 4 (en)].” Mol. Cryst. Liq. Cryst., 34, 139-144 (2000).
119) X.J. Liu, Y. Moritomo, M. Ichida, A. Nakamura and N. Kojima, “Photoinduced Phase Transition ina Mixed-Valence Gold Complex.” Phys. Rev. B 61, 20-23 (2000).
120) X.J. Liu, Y. Moritomo, M. Ichida, A. Nakamura and N. Kojima, “Critical Nucleation in the
Phototransferred Metastable Phase of Cs 2 Au 2 Br 6 .” J. Phys. Soc. Jpn., 69, 1267-1270 (2000).
121) G. Saito, H. Izukashi, M. Shibata, K. Yoshida, L.A. Kushch, T. Kondo, H. Yamochi, O.O. Drozdova,
K. Matsumoto, M. Kusunoki, K. Sakaguchi, N. Kojima and E.B. Yagubskii, “Formation of 2:1
Insulating Complexes of D+D+A2- Alternating Stack and a 4:1 Semimetallic Complex Using
M(dto) 2 Dianions, (M= Ni, Pd or Pt and dto = dithiooxalate).” J. Mater. Chem., 10, 893-910(2000).
122) X.J. Liu, Y. Moritomo, M. Ichida, A. Nakamura and N. Kojima, “Pressure- and Photo-induced
Phase Transition in Gold Complex.” J. Luminescence, 87-89, 649-651 (2000).
123) N. Kojima, W. Aoki, M. Itoi, Y. Ono, M. Seto, Y. Kobayashi and Yu. Maeda, “Charge transfer Phase
Transition and Ferromagnetism in a Mixed-Valence Iron Complex, (n-C 3 H 7 ) 4 N
FeIIFeIII(dto) 3 ](dto= C 2 O 2 S 2 ).” Solid State Commun., 120, 165-170 (2001).
124) X.J. Liu, Y. Moritomo, A. Nakamura, T. Hirao, S. Toyazaki and N. Kojima, “Photoinduced Phase
Transition and Relaxation Behaviour in a Spin-Crossover Fe(II) Complex nafion-[Fe(Hrrz) 3 ] Film.”
J. Phys. Soc. Jpn., 70, 2521-2524 (2001).
125) X.J. Liu, Y. Moritomo, A. Nakamura and N. Kojima, “Pressure- and Photo-induced Phase Transitionin Mixed-Valence Gold Complexes.” Phase Transitions, 74, 51-92 (2001).
126) X.J. Liu, Y. Moritomo, A. Nakamura and N. Kojima, “Dynamical Process of Photo-induced Phase
Transition in a Mixed-Valence Gold Complex.” J. Luminescence, 94-95, 541-544 (2001).
127) T. Nakamoto, Y. Miyazaki, M. Itoi, Y. Ono, N. Kojima and M. Sorai, “Heat Capacity of the MixedValence Complex, {(n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ]} n (dto: dithiooxalato) and Phase Transition due toElectron Transfer and Change in Spin-State of the Whole System.” Angew. Chem.Int. Ed., 40, 47164719 (2001).
128) S. Toyazaki, M. Nakanishi, T. Komatsu, N. Kojima, D. Matsumura and T. Yokoyama, “Control of
Tc by Isomerization of Counter Anion in Fe(II) Spin Crossover Complexes, [Fe(4-NH 2 trz) 3 ](RSO 3 ) 2 .” Synthetic Metals, 121, 1794-1795 (2001).
129) N. Kojima, W. Aoki, M. Seto, Y. Kobayashi and Yu. Maeda, “Reversible Charge-Transfer Phase
Transition in [(n-C 3 H 7 ) 4 N][FeIIFeIII(dto) 3 ] (dto = C 2 O 2 S 2 ).” Synthetic Metals, 121, 1796-1797(2001).
130) Ishikawa, M. Kurasawa, K. Kurasawa, A. Sasane, R. Ikeda and N. Kojima, “35Cl Quadrupole
Relaxation Study on Cs 2 [Au(I)Cl 2 ][Au(III)Cl 4 ] and Cs 2 [Ag(I)Cl 2 ][Au(III)Cl 4 ].”Z.
Naturforsch., 57a, 348-352 (2002).
131) N. Kojima and K. Tsushima, “Recent Progress in magneto-Optics and Research on Its Application.”
Low Temp. Phys., 28, 677-690 (2002).
132) Y. Moritomo, K. Kato, A. Nakamoto, N. Kojima, E. Nishibori, M. Takata and M. Sakata, “LowTemperature Structure of [Fe(ptz) 6 ](BF 4 ) 2 – Determination by Synchrotron-Radiation X-ray
Powder Study –.” J. Phys. Soc. Jpn., 71, 1015-1018 (2002).

133) N. Kojima, S. Toyazaki, M. Itoi, Y. Ono, W. Aoki, Y. Kobayashi, M. Seto and T. Yokoyama, “Searchon Multi-Functional Properties of Spin-Crossover System.” Mol. Cryst. Liq. Cryst., 376, 567-574(2002).
134) M. Ohkubo, T. Komatsu, N. Matsushita, N. Kojima and G. Saito, “Crystal Structure and Physical
Properties of BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene) Salt Coupled with a PhotoSensitive Transition Metal Complex.” Mol. Cryst. Liq. Cryst., 376, 147-152 (2002).
135) N. Kojima, M. Itoi, Y. Ono, M. Ohkubo, Y. Kobayashi and M. Seto, “New-type Phase Transition
Coupled with Spin and Charge in Iron Mixed-Valence System.” Mol. Cryst. Liq. Cryst., 379, 349356 (2002).
136) Y. Ono and N. Kojima, “Study on the Molecular Magnetism in Mixed-Valence Iron Complexes,
M[FeIIFeIII(mto) 3 ] (M = (n-C n H 2n+1 ) 4 N, mto = monothiooxalato (C 2 O 3 S)).” Mol. Cryst. Liq.
Cryst., 379, 349-356 (2002).
137) M. Itoi, N. Kojima, Y. Kobayashi and K. Asai, “Pressure Effect on Ferromagnetic Transition andCharge transfer Phase Transition in a Mixed-Valence Iron Complex, (n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ](dto= C 2 O 2 S 2 ).” Mol. Cryst. Liq. Cryst., 379, 377-382 (2002).
138) X.J. Liu, Y. Moritomo, A. Nakamura, S. Matsuba and N. Kojima, “Pressure Effects on Quasi-OneDimensional Mixed-Valence Gold Complex, [AuCl(DBS)][AuCl 3 (DBS)] (DBS =dibenzylsulfide).” Mol. Cryst. Liq. Cryst., 379, 291-296 (2002).
139) Y. Moritomo, K. Kato, A. Kuriki, N. Nakamoto, N. Kojima, M. Takata and M. Sakata, “Structural
Analysis of [Fe(ptz) 6 ](BF 4 ) 2 under Photo-Excitation – Condensation of Photo-Excited High-Spin
Ions -.” J. Phys. Soc. Jpn., 71, 2609-2612 (2002).
140) Y. Kobayashi, M. Itoi, N. Kojima and K. Asai, “Pressure Effect on Charge transfer Phase Transition
in a Mixed-Valence Iron Complex, (n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ](dto= C 2 O 2 S 2 ).” J. Phys. Soc. Jpn.,
71, 3016-3020 (2002).
141) X.J. Liu, Y. Moritomo, A. Nakamura, S. Matsuba and N. Kojima, “Pressure-induced Phase
Transition in Mixed-Valence Complexes: Comparison of Quasi-1D System with 3D System.”Phys. Stat. Sol. (b), 223, 183-187 (2002).
142) X.J. Liu, Y. Moritomo, T. Kawamoto, A. Nakamoto and N. Kojima, “Optical Hysteresis in a SpinCrossover Complex.” Phys. Rev. B, 67, 012102-1-3 (2003).
143) X.J. Liu, Y. Moritomo, T. Kawamoto, A. Nakamoto and N. Kojima, “Dynamical Phase Transition
in a Spin-Crossover Complex.” J. Phys. Soc. Jpn., 72, 1615-1618 (2003).
144) M. Tozawa, S. Ohkoshi, N. Kojima and K. Hashimoto, “Ion-exchange Synthesis and Magnetooptical Spectra of Colored Magnetic Thin Films Composed of Metal(II) Hexacyanochromate(III).”
Chem. Commun., 1204-1205 (2003).
145) Y. Ono, M. Okubo and N. Kojima, “Crystal Structure and Ferromagnetism of (n-C 3 H 7 ) 4 N[CoIIFeIII(dto) 3 ](dto = C 2 O 2 S 2 ).” Solid State Commun., 126, 291-296 (2003).
146) S. Miyashita and N. Kojima, “Generalized Wajnflasz Model for Charge Transfer Spin-Crossover
Phenomena.” Progress Theor. Phys., 109, 729-739 (2003).
147) A. Nakamoto, Y. Ono, N. Kojima, D. Matsumura, T. Yokoyama, X.J. Liu and Y. Moritomo, “SpinTransition and Its Photo-induced Effect in Spin Crossover Complex Film Based on [Fe(II)(trz) 3 ].”Synth. Metals, 137, 1219-1220 (2003).
148) M. Enomoto, M. Itoi, Y. Ono, M. Okubo and N. Kojima, “Origin of Charge Transfer Phase
Transition and Ferromagnetism in of (n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ] (dto = C 2 O 2 S 2 ).” Synth. Metals,
137, 1231-1232 (2003).

149) N. Kojima, M. Itoi, Y. Ono, M. Okubo and M. Enomoto, “Spin-Entropy Driven Charge-Transfer
Phase Transition in Iron Mixed-Valence System.” Materials Science, 21, 181-189 (2003).
150) N. Kojima, K. Ikeda, Y. Ono, Y. Kobayashi, M. Seto, X.J. Liu and Y. Moritomo, “Control ofChemical Bond and Electronic State for Gold Mixed-Valence Complexes, Cs 2 [AuIX 2 ][AuIIIY 4 ]X, Y = Halogen).” Progress in Coord. Bioinorg. Chem., 6, 115-120 (2003).
151) A. Nakamoto, Y. Ono, N. Kojima, D. Matsumura and T. Yokoyama, “Spin Crossover Complex Film,[FeII(H-trz) 3 ]-Nafion, with a Spin Transition around Room Temperature.” Chem. Lett., 32, 336337 (2003).
152) Y. Moritomo, Y. Isobe, X.J. Liu, T. Kawamoto, A. Nakamoto, N. Kojima, K. Kato and M. Tanaka,“Dynamical Phase Transition under Photo-excitation in a Spin-crossover Complex.” J.
Luminescence, 108, 229-232 (2004).
153) M. Itoi, A. Taira, M. Enomoto, N. Matsushita, N. Kojima, Y. Kobayashi, K. Asai, K. Koyama, T.
Nakano, Y. Uwatoko and J. Yamaura, “Crystal Structure and Structural Transition Caused by
Charge-transfer Phase Transition for Iron Mixed-valence Complex, (n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ](dto = C 2 O 2 S 2 ).” Solid State Commun., 130, 415-420 (2004).
154) M. Itoi, M. Enomoto and N. Kojima, “Ferromagnetism of Iron Mixed-valence Complex, (nC 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ] (dithiooxalato: dto = C 2 O 2 S 2 ).” J. Mag. Mag. Mater. 272-276, 10931094 (2004).
155) Y. Kobayashi, M. Itoi, N. Kojima and K. Asai, “Pressure-induced Charge-transfer Phase Transition
in a Mixed-valence Iron Complex.” J. Mag. Mag. Mater. 272-276, 1091-1092 (2004).
156) N. Kojima, Y. Ono, Y. Kobayashi and M. Seto, “Control of Charge Transfer Phase Transition in
Iron Mixed-valence System, (n-C n H 2n+1 ) 4 N[FeIIFeIII(dto) 3 ](n = 3-6; dto = C 2 O 2 S 2 ).”Hyperfine Interactions, 156-157, 175-179 (2004).
157) K. Ikeda, N. Kojima, Y. Ono, Y. Kobayashi, M. Seto, X.J. Liu and Y. Moritomo, “Study on Chemical
Bond and Electronic State of New Gold Mixed-Valence Complexes, Cs 2 [AuIX 2 ][AuIIIY 4 ](X, Y=Cl, Br, I, etc.).” Hyperfine Interactions, 156-157, 311-314 (2004).
158) M. Sakata, T. Itsubo, E. Nishibori, Y. Moritomo, N. Kojima, Y. Ohishi and M. Takata, ”Charge
Density Study under High Pressure.” J. Phys. Chem. Solids, 65, 1973-1976 (2004).
159) K. Ikeda, Y. Ono, M. Enomoto, N. Kojima, Y. Kobayashi, M. Seto, K. Koyama and Y. Uwatoko,“P-T Phase Diagram and Gold Valence State of New Gold Mixed-Valence Complexes,
Cs 2 [AuIX 2 ][AuIIIY 4 ](X, Y =Cl, Br, I; X ≠ Y).” Ceramics-Silik, 48, 159-164 (2004).
160) X.J. Liu, Y. Moritomo and N. Kojima, “Electronic Phase Diagram of Mixed-Valence Gold Chloride.”
Chinese Phys. Lett., 21, 183-186 (2004)
161) I. Kashima, M. Okubo, Y. Ono, M. Itoi, N. Kida, M. Hikita, M. Enomoto and N. Kojima,“Ferromagnetism and Its Photo-induced Effect in 2D Iron Mixed-Valence Complex
Coupled with Photochromic Spropyran.” Synth. Metals, 153, 473-476 (2005).
162) M. Enomoto and N. Kojima, “Charge Transfer Phase Transition and Ferromagnetism in a Novel
Iron Mixed-Valence Complex (n-C 3 H 7 ) 4 N[FeIIFeIII(tto) 3 ](tto = C 2 OS 3 ).” Synth. Metals, 152, 457460 (2005).
163) M. Okubo, M. Enomoto and N. Kojima, “Study on Photomagnetism of 2D Magnetic Compounds
Coupled with Photochromic Diarylethene Cations.” Synth. Metals, 152, 461-464 (2005).
164) A. Nakamoto, N. Kojima, X.J. Liu, Y. Moritomo and A. Nakamura, “Demonstration of the
Thermally Induced High-Spin – Low-Spin Transition for a Transparent Spin-Crossover Complex
Film, [Fe(II)(Htrz)3]-Nafion (trz = triazole).” Polyhedron, 24, 2909-2912 (2005).

165) M. Okubo, M. Enomoto and N. Kojima, “Reversible Photomagnetism in a Cobalt Layered
Compound Coupled with Photochromic Diarylethene.” Sold State Commun., 134, 777-782 (2005).
166) M. Okubo, M. Enomoto, K. Koyama, Y. Uwatoko and N. Kojima, “Hybrid Organic-Inorganic
Conductor Coupled with BEDT-TTF and Photochromic Nitrosyl Ruthenium Complex.”
Bull.
Chem. Soc. Jpn., 78, 1054-1060 (2005).
167) M. Tada, N. Kojima, Y. Izumi, T. Taniike and Y. Iwasawa, “Chiral Self-Dimerization of VanadiumComplexes on a SiO2 Surface for Asymmetric Catalytic Coupling of 2-Naphthol: Structure,
Performance, and Mechanism.” J. Phys. Chem. B 109, 9905-9916 (2005).
168) N. Matsushita, F. Fukuhara and N. Kojima, “A Three-dimensional Bromo-bridged Mixed-valenceGold(I,III) Compound, Cs 2 AuIAuIIIBr 6 .” Acta Cryst. E 61, i123-i125 (2005).
169) N. Matsushita, A. Tanaka and N. Kojima, ”A Three-dimensional Iodo-bridged Mixed-valenceGold(I,III) Compound, Rb 2 [AuII 2 ] [AuIIII 4 ].” Acta Cryst. E 61, i201-i203 (2005).
170) T. Kajiwara, M. Nakano, Y. Kaneko, S. Takaishi, T. Ito, M. Yamashita, A. Igashira-Kamiyama, H.
Nojiri, Y. Ono and N. Kojima, “A Single-Chain Magnet Formed by a Twisted Arrangement of Ions
with Easy-Plane Magnetic Anisotropy.” J. Am. Chem. Soc., 127, 10150-10151 (2005).
171) J.Y. Son, T. Mizokawa, J.W. Quilty, K. Takubo, K. Ikeda and N. Kojima, “Photoinduced Valence
Transition in Gold Complexes Cs 2 Au 2 X 6 (X = Cl and Br) Probed by X-ray Photoemission
Spectroscopy.” Phys. Rev. B. 72, 235105-1-4 (2005).
172) Y. Moritomo, M. Kamiya, A. Nakamura, A. Nakamoto and N. Kojima, “Cooperative Formation ofHigh-spin Species in a Photoexcited Spin-Crossover Complex,” Phys. Rev. B73, 012103-1-4(2006).
173) M. Itoi, Y. Ono, N. Kojima, K. Kato, K. Osaka and M. Takata, ”Charge Transfer Phase Transition
and Ferromagnetism of Iron Mixed Valence Complexes, (n-C n H 2n+1 ) 4 N [FeIIFeIII(dto) 3 ] (n = 3-6,
dto = C 2 O 2 S 2 ),” Eur. J. Inorg. Chem., 1198-1207 (2006).
174) H. Shimizu, M. Okubo, A. Nakamoto, M. Enomoto and N. Kojima, “Enhancement of the Curie
Temperature by Isomerization of Diarylethene (DAE) for an Organic-Inorganic Hybrid System,
Co 4 (OH) 7 (DAE) 0.5 ·3H 2 O,” Inorg. Chem., 45, 10240-10247 (2006).
175) M. Ferbinteanu, T. Kajiwara, K.Y. Choi, H. Nojiri, A. Nakamoto, N. Kojima, F. Cimpoes, Y.
Fujiwara, S. Takaishi and M. Yamashita, “Binuclear Fe(III)-Dy(III) Single Molecular Magnet.
Quantum Effects and Models,” J. Am. Chem. Soc., 128, 9008-9009 (2006).
176) K. Ikeda, N. Kojima, Y. Kobayashi and M. Seto, “Study on Charge Transfer Interaction and ValenceState of Layered Perovskite-type Mixed-Valence Complex, [NH 3 (CH 2 ) n NH 3 ][(AuII 2 )(AuIIII 4 )(I 3 ) 2 ](n = 7, 8), by Means of 197Au Mössbauer Spectroscopy,” Hyperfine Interactions,
165, 403-407 (2006).
177) M. Okubo, E. Hosono, J. Kim, M. Enomoto, N. Kojima, T. Kudo, H. Zhou and I. Honma, “Nanosize
Effect on High-Rate Li-Ion Intercalation in LiCoO 2 Electrode.” J. Am. Chem. Soc., 129, 74447452 (2007).
178) K. Ikeda, Y. Kobayashi, Y. Negishi, M. Seto, T. Iwasa, K. Nobusada, T. Tsukuda and N. Kojima,“Thiolate-Induced Structural Reconstruction of Gold Clusters Probed by 197Au Mössbauer
Spectroscopy.“ J. Am. Chem. Soc., 129, 7230-7231 (2007).
179) N. Matsushita, H. Ahsbahs, S.S. Hafner and N. Kojima, “Single Crystal X-ray Diffraction Study ofa Mixed-Valence Gold Compound, Cs 2 AuIAuIIICl 6 under High Pressures up to 18 GPa: Pressureinduced Phase Transition Coupled with Gold Valence Transition.” J. Solid State Chem. 180,
1353-1364 (2007).

180) M. Itoi, N. Kida, C. Lin, M. Koeda, N. Kojima, M. Hedo, Y. Uwatoko, Y. Kobayashi, K. Asai, Y.
Ohishi and M. Takata, “Structural Analysis of Iron Mixed-Valence Complex, (n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ](dto = C 2 O 2 S 2 ), under High Pressure.” J. Phys. Soc. Jpn., 76, Suppl. A 190-191(2007).
181) T. Kajiwara, I. Watanabe, Y. Kaneko, S. Takaishi, M. Enomoto, N. Kojima and M. Yamashita,“Direct Observation of the Ground-Spin Alignment of Fe(II)-Fe(III) Single-Chain Magnet by
Muon-Spin Relaxation.” J. Am. Chem. Soc., 129, 12360-12361 (2007).
182) J.Y. Son, K. Takubo, D. Asakura, J.W. Quilty, T. Mizokawa, A. Nakamoto and N. Kojima,“Photoemission Study of Temperature Induced and Photoinduced Spin-State Transitions in SpinCrossover Complex [Fe(ptz) 6 ](BF 4 ) 2 .” J. Phys. Soc. Jpn., 76, 084703-1-6 (2007).
183) K. Kato, M. Takada, Y. Moritomo, A. Nakamoto and N. Kojima, “On-Off Optical Switching of theMagnetic and Structural Properties in a Spin-Crossover Complex.” Appl. Phys. Lett., 90, 2019021-3 (2007).
184) N. Kojima, M. Okubo, H. Shimizu and M. Enomoto, “Control of Magnetism by Isomerization ofIntercalated Molecules in Organic-Inorganic Hybrid Systems.” Coord Chem. Rev., 251, 2665-2673(2007).
185) N. Kojima, M. Enomoto, N. Kida, I. Watanabe and T. Suzuki, “Ferromagnetic and Charge Transfer
Phase Transitions in [FeIIFeIII(dto) 3 ](dto = C 2 O 2 S 2 ) Complexes Examined by Muon Spectroscopy.”
RIKEN Accel. Prog. Rep., 40, v (2007).
186) N. Kida, M. Enomoton, I. Watanabe, T. Suzuki and N. Kojima, “Spin dynamics of the charge-transfer
phase transition of an iron mixed-valence complex observed using muon spin relaxation spectroscopy.”
Phys. Rev. B 77, 144427-1-5 (2008).
187) M. Enomoto, N. Kida, I. Watanabe, T. Suzuki and N. Kojima, “Spin Dynamics of the Ferromagnetic
Transition in Iron Mixed-Valence Complexes, (n-C n H 2n+1 ) 4 N[FeIIFeIII(dto) 3 ] (dto = C 2 O 2 S 2 , n =3-5) by μSR.” Physica. B 404, 642-644 (2009).
188) N. Kida, M. Hikita, I. Kashima, M. Okubo, M. Itoi, M. Enomoto, K. Kato, M. Takata and N. Kojima,“Control of Charge Transfer Phase Transition and Ferromagnetism by Photoisomerization of
Spiropyran for an Organic-Inorganic Hybrid System, (SP)[FeIIFeIII(dto) 3 ] (SP = spiropyran, dto =C 2 O 2 S 2 ).” J. Am. Chem. Soc., 131 212-220 (2009).
189) N. Kida, M. Hikita, I. Kashima, M. Enomoto, M. Itoi and N. Kojima, “Mössbauer Spectroscopic
Study of Photo-Sensitive Organic-Inorganic Hybrid System, (SP) [FeIIFeIII(dto) 3 ] (dto = C 2 O 2 S 2
SP = spiropyran).” Polyhedron, 28, 1694-1697 (2009).
190) M. Enomoto and N. Kojima, “Magnetic Dilution Effect on the Charge Transfer Phase Transition
and the Ferromagnetic Transition for an Iron Mixed-Valence Complex, (n-C 3 H 7 ) 4 N [FeII 1II
III
Polyhedron, 28, 1826-1829 (2009).
x Zn x Fe (dto) 3 ] (dto = C 2 O 2 S 2 ).”191) K. Kagesawa, Y. Ono, M. Enomoto and N. Kojima, “Study on the Valence Fluctuation and theMagnetism of an Iron Mixed-Valence Complex, (n-C 4 H 9 ) 4 N[FeIIFeIII(mto) 3 ] (mto = C 2 O 3 S).”
Polyhedron, 28, 1822-1825 (2009).
192) N. Kojima, M. Enomoto, N. Kida and K. Kagesawa, “Progress of Multi Functional Properties ofOrganic-Inorganic Hybrid System, A[FeIIFeIIIX 3 ] (A = (n-C n H 2n+1 ) 4 N, spiropyran; X = C 2 O 2 S 2 ,C 2 OS 3 , C 2 O 3 S).” Materials 3, 3141-3187 (2010).
193) K. Kagesawa, A. Okazawa, M. Enomoto and N. Kojima, “Study on the Rapid Spin Equilibrium in
Ph 4 P[ZnIIFeIII(mto) 3 ] (mto = monothiooxalato).” Chem. Lett. 39, 872-873 (2010).
194) E. Hosono, Y. Wang, N. Kida, M. Enomoto, N. Kojima, M. Okubo, H. Matsuda, Y. Saito, T. Kudo,

I. Honma and H. Zhou, “Synthesis of Triaxial LiFePO4 Nanowire with a VGCF Core Column anda Carbon Shell through the Electrospinning Method.” Appl. Mater. Interfaces, 2, 212-218 (2010).
195) K. Kagesawa, N. Kida, Y. Ono, M. Enomoto and N. Kojima, “Linkage-isomerization and Chargetransfer in the Formation of Iron Mixed-Valence Complexes, (n-C 3 H 7 ) 4 N [FeIIFeIII(dto) 3 ](dto =C 2 O 2 S 2 ) and (n-C 4 H 9 ) 4 N[FeIIFeIII(mto) 3 ] (mto = C 2 O 3 S).” J. Phys.: Conf. Ser., 217, 012034012037 (2010).
196) A. Sugahara, M. Enomoto and N. Kojima, “Isomerization Effect on Counter Anion on the Spin
Crossover Transition in [Fe(4-NH 2 trz) 3 ](CH 3 C 6 H 4 SO 3 ) 2 ·nH 2 O.” J. Phys.: Conf. Ser., 217,
012128-012131 (2010).
197) Z.Z. He, C.S. Lin, W.D. Cheng, A. Okazawa, N. Kojima, J. Yamaura and Y. Ueda, “Unusually Large
Magnetic Anisotropy in a CuO-Based Semiconductor Cu 5 V 2 O 10 .” J. Am. Chem. Soc. 133, 12981300 (2011).
198) M. Okubo, D. Asakura, Y. Mizuno, T. Kudo, H. S. Zhou, A. Okazawa, N. Kojima, K.
Ikedo, T. Mizokawa and I. Honma, “Ion-Induced Transformation of Magnetism in a
Bimetallic CuFe Prussian Blue Analogue.” Angew. Chem. Int. Ed., 50, 6269-6273(2011).
199) T. Shimada, A. Okazawa, N. Kojima, S. Yoshii, H. Nojiri and T. Ishida, “Ferromagnetic Exchange
Couplings Showing a Chemical Trend in Cu-Ln-Cu Complexes (Ln = Gd, Tb, Dy, Ho, Er).” Inorg.
Chem., 50, 10555-10557 (2011).
200) T. Tsukuda, Y. Negishi, Y. Kobayashi and N. Kojima, “197Au Mössbauer Spectroscopyof Au 25 (SG) 18 - Revisited.” Chem. Lett., 40, 1292-1293 (2011).
201) H. Kamebuchi, T. Jo, H. Shimizu, A. Okazawa, M. Enomoto and N. Kojima,“Development of pH-Sensitive Spin-crossover Iron(II) Complex Films,[FeII(diAMsar)]–Nafion: Manipulation of the Spin State by Proton Concentration.”
Chem. Lett., 40, 888-889 (2011).
202) A. Okazawa, H. Nojiri, T. Ishida and N. Kojima, “Single-Molecule Magnet Behavior Enhanced by
Magnetic Coupling between 4f-3d Spins.” Polyhedron, 30, 3140-3144 (2011).”203) A. Okazawa, K. Fujiwara, R. Watanabe, N. Kojima, S. Yoshii, H. Nojiri and T. Ishida, “Exchange
Couplings in One-dimentionally Arrayed 4f-3d Heterometallic [Ln 2 Cu 2 ] n Compounds. A
Chemical Trend of the Coupling Parameter.” Polyhedron, 30, 3121-3126 (2011).
204) A. Sugahara, K. Moriya, M. Enomoto, A. Okazawa and N. Kojima, “Study on the Spin-Crossover
Transition in [Fe(cis-/trans-stpy) 4 (X) 2 ] (stpy: styrylpyridine, X: NCS, NCBH 3 ) under High
Pressure toward Ligand-Driven Light-Induced Spin Change.” Polyhedron, 30, 3127-3130 (2011).
205) M. Enomoto, N. Kida, N. Kojima, I. Watanabe, T. Suzuki and T., Ishii, “Study on the Pressure
Induced Charge Transfer Phase Transition in (C 5 H 11 ) 4 N [FeIIFeIII(C 2 O 2 S 2 ) 3 ] by Means of μSR
Spectroscopy.” Polyhedron 30, 3137–3139 (2011).
206) N. Kojima, K. Kagesawa, A. Okazawa and I. Watanabe, “Study on the Spin-Equilibrium and theSucceeding Magnetic Phase Transitions in the Iron(III) Complex by Means of μSR Spectroscopy.”
RIKEN Accel. Prog. Rep., 45, 194 (2011).
207) K. Fujiwara, A. Okazawa, N. Kojima, G. Tanaka, S. Yoshii and H. Nojiri,“Oximato-Bridged
Light-Lanthanide Ln 4 Cu Complexes Showing Ferromagnetic Ln-Cu Exchange Coupling,”
Chem. Phys. Lett., 530, 49-54 (2012).
208) Y. Ono, A. Okazawa, N. Kida, M. Enomoto and N. Kojima, “Study on the Ferromagnetic State in
Iron Mixed-Valence Complexes, A[FeIIFeIII(dto) 3 ](A = (n-C n H 2n+1 ) 4 N, spiropyran; dto =C 2 O 2 S 2 ) by Means of Mössbauer Spectroscopy.” Hperfine Interactions, 207, 139-143 (2012).
209) A. Nakamoto, H. Kamebuchi, M. Enomoto and N. Kojima, “Study on the Spin Crossover Transition
and Glass Transition for Fe(II) Complex Film, [Fe(II)(H-triazole) 3 ]@Nafion, by Means of
Mössbauer Spectroscopy.” Hyperfine Interactions, 205, 41-45 (2012).
210) N. Kojima, K. Ikeda, Y. Kobayashi, T. Tsukuda, Y. Negishi, G. Harada, T. Sugawara and M. Seto,“Study on the Structure and Electronic State of Thiolate-Protected Gold Clusters by Meansof 197Au Mössbauer Spectroscopy.” Hyperfine Interactions, 207, 127-131 (2012).
211) D. Asakura, M. Okubo, Y. Mizuno, T. Kudo, H. S. Zhou, K. Ikedo, T. Mizokawa, A. Okazawa andN. Kojima, “Fabrication of Defectless Cyanide Bridged Perovskite Framework for Enhanced
Electrochemical Ion Storage Ability.” J. Phys. Chem. C 116, 8364-8369 (2012).
212) N. Kojima, N. Kida, A. Okazawa and M. Enomoto, “Size Effect of Intercalated Cation on the Charge
Transfer Phase Transition and Ferromagnetism for Iron Mixed-Valence System,
A[FeIIFeIII(C 2 O 2 S 2 ) 3 ] (A = (C n H 2n+1 ) 4 N, (C m H 2m+1 ) 3 (C n H 2n+1 )N).” Mössbauer Effect
Reference and Data Journal, 35, 154-165 (2012).
213) Y. Mizuno, M. Okubo, K. Kagesawa, D. Asakura, T. Kudo, H.S. Zhou, K. Oh-ishi, A. Okazawa andN. Kojima, “Precise Electrochemical Control of Ferromagnetism in a Cyanide-Bridged Bimetallic
Coordination Polymer.” Inorg. Chem., 51, 10311-10316 (2012).
214) H. Ida, A. Okazawa, N. Kojima, R. Shimizu, Y. Yamada and M. Enomoto, “Effect of Nonmagnetic
Substitution on the Magnetic Properties and Charge-Transfer Phase Transition of an Iron MixedValence Complex, (n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ] (dto = C 2 O 2 S 2 ).” Inorg. Chem., 51, 8989-8996(2012).
215) Z. Z. He, W. L. Zhang, W. D. Cheng, A. Okazawa and N. Kojima, “K 4 Fe 4 P 5 O 20 : A New Mixed
Valence Microporous Compound with Elliptical Eight-Ring Channels.” Inorg. Chem., 51, 74697471 (2012).
216) T. Ishida, R. Watanabe, K. Fujiwara, A. Okazawa, N. Kojima, G. Tanaka, S. Yoshii and H. Nojiri,“Exchange coupling in TbCu and DyCu single-molecule magnets and related lanthanide andvanadium analogs.” Dalton Trans., 41, 13609-13609, (2012).
217) N. Kano, N. Yoshinari, Y. Shibata, M.Miyachi, T.Kawashima, M. Enomoto,, A.Okazawa, N.
Kojima, J.D.Guo and S. Nagase, “Anionic Iron Complexes with a Bond between an Ate-Type
Pentacoordinated Germanium and an Iron Atom.” Organometallics, 31, 8059-8062 (2012).
218) N. Kojima, Y. Kobayashi, Y. Negishi, M. Seto and T. Tsukuda, “Structural evolution of
glutathionate-protected gold clusters studied by means of 197Au Mössbauer
Spectroscopy.” Hyperfine Interactions, 217, 91-98 (2013).
219) M. Okubo, K. Kagesawa, Y. Mizuno, D. Asakura, E. Hosono, T. Kudo, H. Zhou, K. Fujii, H. Uekusa,
S. Nishimura, A. Yamada, A. Okazawa and N. Kojima, “Reversible Solid State Redox of an
Octacyanometallate-bridged Coordination Polymer by Electrochemical Ion Insertion/extraction.”
Inorg. Chem. 52, 3772-3779 (2013).
220) N. Kojima, K. Ikeda, Y. Kobayashi and M. Seto, “Study on the electronic state of gold mixedvalence complexes, Cs 2 [Au(I)X 2 ][Au(III)Y 4 ](X, Y = Cl, Br, I) by means of 197Au Mössbauer
spectroscopy.” Mössbauer Effect Reference and Data Journal, 36, 57-72 (2013).
221) Y. Seki, A. Okazawa, M. Enomoto, J. Harada, K. Ogawa and N. Kojima, “Alternating Ferro- andAntiferromagnetic Couplings in One-dimensional Chain Hexachlorodicuprate(II), (MV)[CuCl 3 ] 2(MV = methyl viologen).” Current Inorg. Chem. 3, 94-100 (2013).
222) J. Yoshida, N. Kida, A. Okazawa and N. Kojima, “Cation Size Effect on Photomagnetism andCharge Transfer Phase Transition of Iron Mixed-valence Complexes with Spiropyrans.”
Polyhedron, 66, 100-107 (2013).
223) Z. He, W. Zhang, W. Cheng, A. Okazawa and N. Kojima, “Long-range and Short-range Orderingsin K 4 Fe 4 P 5 O 20 with a Natrolite-like Framework.” Dalton Ttransactions, 42, 5860-5865 (2013).
224) A. Okazawa, T. Shimada, N. Kojima, S. Yoshii, H. Nojiri and T. Ishida, “Exchange Coupling and
Its Chemical Trend Studied by High-Frequency EPR on Heterometallic [Ln 2 Ni] Complexes.”
Inorg. Chem. 52, 13351-13355 (2013).
225) Y. Mizuno, M. Okubo, E. Hosono, T. Kudo, K. Oh-ishi, A. Okazawa, N. Kojima, R. Kurono, S.
Nishimura and A. Yamada, “Electrochemical Mg2+ Intercalation into a Bimetallic CuFe PrussianBlue Analog with Aqueous Electrolytes.” J. Materials Chemistry A 1, 13055-13059 (2013).
226) Y. Negishi, W. Kurashige, Y. Kobayashi, S. Yamazoe, N. Kojima, M. Seto and T. Tsukuda,“Au 24 Pd 1 (SC 12 H 25 ) 18 Probed by 197Au Mössbauer and Pd K-edge EXAFS Spectroscopy.” J.
Phys. Chem. Lett. 4, 3579-3583 (2013).
227) N. Kojima, H. Kobayashi, A. Okazawa, I. Kawasaki, I. Watanabe, “Study on the static and dynamic
spin crossover phenomena in tripyrazolylmethane iron(II) complexes by means of mSR
spectroscopy,” RIKEN Accel. Prog. Rep., 47, 258 (2014).
228) K. Nomura, S. Taya, A. Okazawa and N. Kojima, “Sol-gel synthesis and dilute magnetism of nano
MgO powder doped with Fe.” Hyperfine Interactions, 226, 161-169 (2014).
229) A. Okazawa, J. Yoshida, N. Kida, I. Kashima, W. Murata, M. Enomoto and N. Kojima, “Study on
spin configuration in photoresponsive iron mixed-valence complexes by Mössbauer spectroscopy.”
Hyperfine Interactions, 226, 351-357 (2014).
230) T. Fujinami, M. Koike, N. Matsumoto, Y. Sunatsuki, A. Okazawa and N.Kojima, “Abrupt Spintransition and thermal hysteresis of iron(III) complex [FeIII(Him) 2 (hapen)]AsF 6 (Him = imidazole,H 2 hapen = N,N′-bis(2-hydroxyacetophenylidene)ethylenediamine).” Inorg. Chem., 53, 22542259 (2014).
231) H. Kamebuchi, M. Okubo, A. Okazawa, M. Enomoto, J. Harada, K. Ogawa, G. Maruta, S. Takeda,
N. Kojima, C. Train and M. Verdaguer, “A Tricky Water Molecule Coordinated to a Verdazyl
Radical-Iron(II) Complex: a Multitechnique Approach.” Phys. Chem. Chem. Phys. 16, 9086 9095 (2014).
232) N. Kojima, M. Itoi and Y. Miyazaki, “Phase Transitions due to Charge Transfer in Mixed-Valence
Assembled Metal Complexes, A[FeIIFeIII(dto) 3 ] (A = (n-C n H 2n+1 ) 4 N, spiropyran; dto = C 2 O 2 S 2 ),”Current Inorg. Chem., 4, 85-99 (2014).
233) A. Sugahara, N. Tanaka, A. Okazawa, N. Matsushita and N. Kojima, “Photochromic Property ofAnionic Spiropyran Having Sulfonate-substituted Indoline Moiety.” Chem. Lett., 43, 281-283(2014).
234) H. Kamebuchi, A. Nakamoto, T. Yokoyama and N. Kojima, “Fastener Effect on Uniaxial ChemicalPressure for One-Dimensional Spin-Crossover System, [FeII(NH 2 -trz) 3 ] (C n H 2n+1 SO 3 ) 2 ·xH 2 O:
Magnetostructural Correlation and Ligand Field Analysis,” Bull. Chem. Soc. Jpn., 88, 419-430(2015).
235) K. Nomura, P. de Souza, S. Hirai and N. Kojima, “Mӧssbauer Analysis of Iron Ore and Rapidly
Reduced Iron Ore Treated by Micro-discharge Using Carbon Felf.” J. Radioanal. Nucl. Chem.,
303, 1259-1263 (2015).
236) A.Taufiq, Sunaryono, E.G.R. Putra, A. Okazawa, I. Watanabe, N. Kojima, S. Pratapa, Darminto,“Nanoscale Clustering and Magnetic Properties of Mn x Fe 3-x O 4 Particles Prepared from Natural

Magnetite,” J. Superconductivity and Novel Magnetism, 28, 2855- 2863 (2015).
237) N. Tanaka, A. Okazawa, A. Sugahara, N. Kojima, “Development of a Photoresponsive OrganicInorganic Hybrid Magnet: Layered Cobalt Hydroides Intercalated with Spiropyran Anion,” Bull.
Chem. Soc. Jpn., 88, 1150-1155 (2015).
238) Sunaryono, A. Taufiq, E. G. R. Putra, A. Okazawa, I. Watanabe, N. Kojima, S. Rugmai, S.
Soontaranon, M. Zainuri, Triwikantoro, S. Pratapa, Darminto, “Small-Angle X-Ray Scattering
Study on PVA/Fe 3 O 4 Magnetic Hydrogels,” Nano, World Scientific, 11, 1650027-1-12 (2016).
239) M. Enomoto, I. Watanabe, N. Kojima, “Dynamical Behavior of the Charge Transfer Phase
Transition in Dithiooxalato-Bridged Iron Mixed-Valence System,” Current Inorg. Chem., 6, 49-60(2016).
240) S. Goda, M. Nikai, M. Ito, D. Hashizume, K. Tamao, A. Okazawa, N. Kojima, H. Fueno, K. Tanaka,
Y. Kobayashi, T. Matsuo, “Synthesis and Magnetic Properties of Linear Two-coordinate
Monomeric Diaryliron(II) Complexes Bearing Fused-ring Bulky “Rind” Groups,” Chem. Lett.
45, 634–636 (2016).
241) K. Nomura, S. Suzuki, Y. Koike, H. Li, A. Okazawa, N. Kojima, “Magnetic property andMossbauer analysis of SrSn 1−x Fe x O 3 prepared by a sol-gel method,” Hyperfine Interactions, 237,
26-1-10 (2016).
242) A. Sugahara, H. Kamebuchi, A. Okazawa, M. Enomoto, N. Kojima, “Control of Spin-Crossover
Phenomena in One-Dimensional Triazole-Coordinated Iron(II) Complexes by Means ofFunctional Counter Ions.” Inorganics, 5, 50-1-23 (2017).
243) A. Taufiq, A.T. Sunaryono, N. Hidayat, A. Hidayat, E. Giri, R. Putra, A. Okazawa, I. Watanabe, N.
Kojima, S. Pratapa, Darminto, "Studies on Nanostructure and Magnetic Behaviors of Mn-Doped
Black Iron Oxide Magnetic Fluids Synthesized from Iron Sand" Nano, World Scientific, 12 (09),1750110-1-11 (2017).
244) N. Shida, Y. Suzawa, M. Inaba, A. Okazawa, N. Kojima, M. Enomoto, “Magnetic Properties of Vsubstitution Effect an Iron Mixed-Valence Complex,” Polyhedron, 136, 143-148 (2017).
245) R. Tanaka, A. Okazawa, H. Konaka, A. Sasaki, N. Kojima and N. Matsushita, ” UniqueHydration/Dehydration-Induced Vapochromic Behavior of a Charge-Transfer Salt Comprising
Viologen and Hexacyanidoferrate(II),” Inorg. Chem. 57, 2209-2217 (2018).
246) R. Tanaka, A. Okazawa, N. Kojima and N. Matsushita, “Ionic Crystal Containing Protons (H+) as
Counter Cations: Preparation and Crystal Structure of a Salt of 4,4’-Bipiperidine-1,1’-diium andHexacyanidoferrate(II),” Chem. Lett., 47, 697-699 (2018).

60 Review, Bulletin, Report, etc.
Representative bulletins, etc.
1) N. Kojima, “197Au and 129I Mössbauer Spectroscopy of the Perovskite-type Mixed-Valence
Compound Cs 2 Au 2 I 6 ,” Proceedings of XXX Zakopane School of Physics (Zakopane, Poland,1995), pp. 326-338.
2）N. Kojima, S. Matsuba, M. Seto, Y. Kobayashi and Yu. Maeda, “197Au Mössbauer Spectra of One
Dimensional Au Mixed-Valence Complex [AuCl(dbs)][AuCl 3 (dbs)],” KURRI Progress Report,
42 (1998).
3）N. Kojima, W. Aoki, M. Seto, Y. Kobayashi and Yu. Maeda, “Reversible Charge Transfer Phase
Transition and Ferromagnetism in Mixed-Valence Complex, (n-C 3 H 7 ) 4 N[FeIIFeIII(dto) 3 ] (dto =C 2 O 2 S 2 ),” KURRI Progress Report, 56 (1999).
4）S. Toyazaki, D. Matsumura, T. Yokoyama and N. Kojima, “Control of Tc by Isomerization of Anionin Fe(II) Spin-Crossover Complexes, [Fe(4-NH 2 trz) 3 ] (o-, m-, p-NH 2 C 6 H 4 SO 3 ) 2 •2H 2 O,”
Photon Factory Activity Report, 103 (2000).
5）Y. Ono, N. Kojima, M. Seto and Y. Kobayashi, “Study on the Molecular Magnetism in MixedValence Iron Complexes, M[FeIIFeIII(mto) 3 ](M = (n-C n H 2n+1 ) 4 N, mto = monothiooxalato(C 2 O 3 S)),” KURRI Progress Report, 16 (2001).
6）K. Ikeda, N. Kojima, Y. Ono, Y. Kobayashi and M. Seto, “Mössbauer Spectroscopy of New-TypeGold Mixed-Valence Complexes Cs 2 [Au(I)X 2 ][Au(III)Y 4 ](X, Y = Cl, Br, I, etc.) with Bridging
Hetero-Halogen,” KURRI Progress Report, 59 (2002).
7) Y. Kobayashi, S. Kitao, M. Kurokuzu, Y. Negishi, T. Tsukuda, N. Kojima and M. Seto, “197Au
Mӧssbauer Study of Au Nanoparticles,” KURRI Progress Report, PR2-7 (2013).
8) N. Kojima, Y. Kobayashi and M. Seto, “Determination of the Structure and Electronic State of
Thiolate-Protected Hetero-Metal Cluster, Au 24 Pd 1 (SC 12 H 25 ) 18 , by Means of 197Au Mӧssbauer
Spectroscopy,” KURRI Progress Report, PR2-8 (2013).

28 Monographs
Representative monographs1) S. Sugano and N. Kojima (ed.) “Magneto-Optics,” (Springer, 2000).
2) N. Kojima and K. Ikeda, “Magnetochromism of Inorganic Materials.” in “Inorganic Chromotropism”
ed. Y. Fukuda (Kodansha/Springer, 2007), pp. 355-367.
3) N. Kojima, ”Photo-induced Spin Crossover Phenomena.” in “Inorganic Chromotropism” ed. Y.
Fukuda (Kodansha/Springer, 2007), pp. 258-273.
4) N. Kojima and A. Sugahara, “Spin-Crossover and Related Phenomena Coupled with Spin, Photon
and Charge.” in “Mössbauer Spectroscopy: Applications in Chemistry, Biology andNanotechnology”, ed. V.K. Sharma, C. Klingelhöfer, T. Nishida (Wiley Inc., 2013), pp. 152-176.
5）M. Okubo and N. Kojima, “Photomagnetic Organic-inorganic Hybrid Materials.” in “Research
Advances in Magnetic Materials.”, ed. C. Toulson, D. Marwick, (Nova Science Publishers, Inc.
2013), pp. 55-76.
6) H. Kamebuchi, M. Enomoto and N. Kojima, “Progress of Multifunctional Spin Crossover Complex
Film Based on Nafion,” in “Nafion: Properties, Structure and Applications”, ed. A. Sutton, (Nova
Science Publishers, Inc., 2016), pp. 119-140.