Kiyokazu Fuke
Emeritus Professor, Kobe University[Present Position]
Fellow at Toyota Physical and Chemical Research Institute[Research Field]
Molecular Science, Laser Spectroscopy, Cluster Chemistry[Date of Birth]
February 8, 1947

[Sex] Male[Nationality] Japan[Graduation, Degree, and Postdoctoral]
Mar. 1970 Faculty of Science (chemistry). Sizuoka University
Mar. 1972 Graduate School of Science, Master Course, University of Tokyo
Mar. 1975 Graduate School of Science, Doctor Course (chemistry major), University of
Tokyo
Mar. 1975 Doctor of Science, University of Tokyo(Thesis title: Electronic structures and intavalence and extravalence transitions of
unsaturated organic compounds)
Jun 1975 Postdoctoral University of Michigan – Ann Arbor (with M Tamres)Jun 1976 Postdoctoral University of Southern California – Los Angeles (with O Schnepp)[Professional Career]Dec. 1977 - Mar. 1981
Apr. 1981 - Oct. 1988
Nov. 1988 - Jun 1995
Jul. 1995 – Mar. 2010
[Apr. 2004 - Mar.2005 ;Feb. 2012 - Mar, 2016
Apr. 2017 – Present

Research Associate, Kanazawa University.
Assistant Professor and Lecturer of Chemistry, Keio
University.
Associate Professor, Institute for Molecular Science.
Professor of Chemistry, Kobe University.
Visiting Professor, University of Tokyo (Chemistry Dept.)]
Researcher, Institute for Molecular Science.
Fellow at Toyota Physical and Chemical Research Institute[Membership]
The Chemical Society of Japan, Japan Society for Molecular Science, The SpectroscopicalSociety of Japan, American Chemical Society.

Research Overview
Toyota Physical and Chemical Research Institute,Kiyokazu Fuke

１．Before 1981
In the spring of 1970, I started research as a graduate student under Prof. Saburo Nagakura in Department ofChemistry and Institute for Solid State Physics (ISSP) of Tokyo University. The research subject was the UV
and

VUV

spectroscopies

onsinglecrystalsofunsaturatedorganic

compounds

using

microspectrophotometer and normal-incidence reflection spectrophotometer. The spectrometers,
which were constructed by Dr. Koji Kaya, were in Nagakura’s laboratory at Wako campus of Riken. We
successfully elucidated the intra- and inter-molecular interaction of aromatic rings, for example, in paracyclophane derivatives1 and in perylene crystals.
After two years of postdoctoral works in US (with Prof. M. Tamres of University Michigan and with Prof. O.
Schnepp of University of Southam California), I moved to Kanazawa University to join the group of Prof.
Michiya Itoh as a research associate. He kindly proposed me to start a new research project of my own. Because
at that time the experimental facilities were so limited as were in the other laboratories in Japan, I decided to
study the electronic relaxation processes of organic molecules in solution using the thermal lensing technique,which requires a relatively simple optical setup. Around that time, the electronic relaxation processes were oneof the subjects of intensive studies. However, almost all of the studies were concerned with the observationof the photoemission from the excited states; by measuring the decay time and the yield of emission, thereactivities in the excited states were examined. The technique I had chosen is bases on the detection of transient
fluctuation of the refractive index of medium, which is referred to as a thermal lens effect. The effect is induced
by a local heating of the medium through a nonradiative deactivation of the excited states. This technique isenable us to carry out an extremely sensitive absorption spectroscopy. Because the response time of therefractive-index fluctuation is determined by the sound velocity in the medium, by monitoring the transient
thermal lens, I expected we could attain a few ns time-resolution in a focused laser beam to study the electronic
relaxation process during the chemical reactions. I invented a transient thermal-lens method to directly observe
the time responses of the excited-state decay and the photoinduced reactions involving reaction intermediates.
We demonstrated for the first time the application of this technique to the photochemical reactions producing aradical species, difficult to directly detect. With this method, we also succeeded to observe the singlet oxygen(1O2; 1∆g) of an extremely low emission yield, and determined the lifetimes of 1O2 in various organic solventsand elucidated its importance as a chemical intermediate.2
2. Research at Institute for Molecular Science
In the spring of 1981, I moved to Department of Chemistry, Faculty of Science and Technology, Keio
University to work with Prof. Koji Kaya. He just started a new laboratory in the newly-established Department.
We began constructing the setup of the pulsed supersonic jet technique combined with tunable dye lasers.
The former technique, first introduced to molecular spectroscopy by R. E. Smalley in the late 1970's,3 allows
us to cool the translational temperature below a few kelvin and to freeze out the rotational motion of even

medium-sized molecules such as benzene. The spectra of all such molecules could be studied without rotational
congestion. Many research groups in the world started to study the visible and UV spectra of the jet-cooled
molecules by using laser-induced fluorescence excitation techniques. For us, most important feature ofsupersonic beam was the formation of clusters of atoms and molecules. The studies of weakly bound clusters
allow us to understand how the properties of atomic and molecular clusters vary as a function of size, and to
examine the stepwise development of condensed phase attributes.

Thus they allow us to bridge the gap

between isolated molecules and condensed matter. We successfully set up a state-of-the-art supersonic beam
apparatus with a pulsed supersonic nozzle and a quadrupole mass filter. The machine could be also adapted fora resonant two-photon ionization (R2PI) detection technique in addition to the ordinary fluorescence
detection, so that we immediately started to study the spectrum of mass-selected clusters in the supersonicbeam. We used this to probe the structure and dynamics of various molecular clusters, particularly focusing on
the question of microscopic solvation process.
We also constructed a laser vaporization cluster beam apparatus, which adapted a Smalley's technique4, andallowed us to produce the cold atom clusters of any element in the periodic table. We initiated a series ofstudies on metal clusters, which are closely related with surface chemistry. In the following paragraphs, I
present the brief summaries of some of pioneering works not only on jet cooled spectra of van der Waals
complexes, but also on spectroscopy and reaction dynamics for the hydrogen-bonded clusters.
3. Spectroscopy on Hg-rare gas van der Waals Complexes in molecular beam
The spectroscopic profiles of the metal atoms perturbed by rare gases have been the subject of numerous
investigations for many years, because they are necessary to understand the interaction potentials and to
explore a lamp material. Previously the spectral studies of metal atom-rare gas complexes were possible onlyat high temperature, and therefore the observed
absorption and emission spectra were so broad for
precise analysis of the electronic structures. In
particular, the profile of the 253.7 nm resonanceline (3P1) of mercury atom (Hg) perturbed by raregases had been the subject of extensive studies
because of the above-mentioned importance aswell as its application to the photosensitizedchemical reactions. In our study, with freeFig. 1(a) Fluorescence excitation spectrum of Hg-Ar

complex in a supersonic jet. The intense band at 253. 7 nm is3

due to free Hg atom ( P1). The dotted lines shows the typicalemission profile of the resonance line broaden by Ar observedin a high-temperature cell experiment.

expansion of Hg rare-gas mixtures, the Hg-rare gas
molecules

withvibrationalandrotationaltemperatures below a few kelvin are generated.
Figure 1 shows the fluorescence excitation
spectrum of Hg - Ar van der Waals complex, in

which the vibronic transitions to the Π- and Σ-type excited states are clearly resolved in the lower and higher

energy regions of the 3P1 resonance line.5 From the analysis of the spectrum in Fig. 1 and the dispersed
fluorescence spectra obtained by the excitation at each vibronic bands, we determined for the first time theprecise interatomic potential functions for the ground and the Π- and Σ-type excited states. We also examinedthe complexes with the other rare gases and molecules such as N2, CO, and CH4, and obtained rich informationon the spectroscopy and dynamics of the excited states of the van der Waals molecules. After our studies, thistechnique was extensively used by the other groups in the studies on the metal atom - molecule interaction andbecome the standard tools by replacing the conventional techniques such as high-temperature cell experiments.
4．Stepwise solvation process of phenol in small water clusters
Hydrogen bonding was recognized for a long time as being important in a wide variety of the physical andchemical phenomena, including solvation effects. Numerous valuable experimental measurements on H
bonding were mostly carried out for bulk systems, for examples, by observing the absorption and fluorescence
spectra in liquids, by determining the boiling and melting point changes, and with X-ray crystallographic
measurements of H bonded solids. In these experimental methods, the effects of bulk solvation on the solutesystem have to be convoluted with molecular aspectsof the H bonding, to elucidate fully the details of theinfluence of the H bonds. With the advent ofsupersonic molecular beams, H- bonded clusters canbe created with a size-selective fashion and thepowerful laser-based spectroscopic techniques canbe applied to the size-selected species to deconvolvethe effects of the solvent from H-bonding
interactions. Furthermore, the cooling of vibrationaland rotational modes in the cluster considerably
simplifies assignment of the optical spectra.
From these points of view, we initiated the study
for the first time on the hydration process of phenol,
which is the chromophore of an important aminoacid such as tyrosine. We used a mass-selected
multiphoton

ionization(MPI)

techniquetospectroscopically examine the effects of theFig. 2 MS-MPI spectra of the S1-S0 transitions of phenol-

stepwise H-bonds of water molecules to phenol.

(H2O)n; (a) n=0,(b) n=1, (c) n=2, and (d) n=3.The origin of

Figure 2 shows the vibronic transitions of the-1

phenol monomer is observe at 36352 cm ,while those of-1n=1 and n=2 are 35996 and36259 cm , respectively.

electronic absorption spectra of phenol (H2O)n (n=04) at near origin of the S1 - S0 transition.6 With anaddition of the first water molecule, the 0 - 0 transition of phenol molecule is shifted to the red by 356 cm-1,
while the band shifts to the blue by 263 cm-1 by the second water molecule. On the other hand, the 0 - 0 band

of n =3 shifts only slightly to the red from that of n = 2. From the spectral shifts, the first water molecule inphenol-(H2O) attaches to the proton of the O―H group of phenol and phenol acts as a proton donor in thehydrogen bonding, and the second water attaches to the oxygen atom of the O―H group of the monohydrated
phenol and phenol behaves as a proton acceptor to the second water. The second water also accept the protonof the first water to stabilize the system and form a cyclic structure. In these studies, we demonstrated for the
first time how the spectroscopic study on microscopic solvation with hydrogen bonds is informative to mimic
the solvation process in bulk solution. After these pioneer studies, the spectroscopic studies on microscopic
solvation with polar molecules became one of the main subjects in the gas-phase cluster research.7

5. Dynamics of proton-transfer reaction in model hydrogen bonded base pairs
Proton transfer processes have received a great deal of attention by the broad scientific community due toboth the fundamental interest in their behavior as well as their significance in chemical and biological processes.
Hydrogen-bonded amino groups are ubiquitous in nature; the hydrogen bonds involving the amino groups playa key role in the nucleic acid base pairing in DNA and RNA; an amino group donates a hydrogen to anelectronegative oxygen or nitrogen. The N–H groups of the nucleic acid bases have a complemental role in thepairing for the genetic coding in DNA and RNA. Also, the hydrogen bond strength determines the possible
occurrence of proton or hydrogen transfer between donating and accepting groups, to form tautomers. Amongthese hydrogen bonded dimers, 7-Azaindole dimer (7-AI)2 has been one of the most intensively studied modelcompound in nucleic acid base pairs. Electronic excitation of (7-AI)2 in the UV spectral region results in excitedstate double proton transfer (DPT), leading to the formation of tautomer, which emits the visible fluorescencepeaking at 520 nm. The excited state double proton transfer in 7-AI dimer was first examined in early steadystate solution-phase experiments with various laser spectroscopic techniques to clarify whether this process canbe of signiﬁcance in mutagenesis. In solution, however, the solvation effect blurred the spectroscopic details
and the reaction features of model base pairs, and as a result, the understanding of the characteristics of the
proton transfer reaction was very limited. To answer the questions and to unveil the potential energy surfaces
involved and the reaction dynamics progressed, the absorption and emission properties of supersonically cooled(7-AI)2 were examined for the first time at vibrational temperature of less than a few kelvin in molecular beam.
Figure 3 shows a typical fluorescence excitation spectrum of (7-AI)2 near the origin at 32252 cm-1 bymonitoring the visible tautomer emission; The spectrum corresponds to the action spectrum of the protontransfer reaction,8 and consists of the progressions and combinations of 98 and 120 cm-1 vibrations which areassigned to the intermolecular bending and symmetric stretching vibrational modes. The bandwidth of the origin
band (5 cm-1) is much wider than that of monomer (2 cm-1), which indicates a spectral resolution of ourexperimental system. The v' = 1 and v' = 2 bands of the 120 cm-1 vibration exhibit the bandwidths of 10 and 30
cm-1 (fwhm), from which the excited-state lifetimes are estimated to be 0.5 and 0.2 ps, respectively. The results
imply that the proton transfer reaction proceed from the zero vibrational level in the first excited state throughtunneling process. The spectrum also exhibits the other important features of the reaction dynamics. One ofexamples is a vibrational mode dependence of the reaction rate. As seen in Fig. 3, the bandwidth of the v' = 1
band of the 98-cm-1 vibration is only 3 cm-1, while that of the combination band with the 120 cm-1 vibration at

215 cm-1 above the 0-0 band again increases more than twice (7 cm-1), indicating the enhancement of the rateof the DPT reaction at this-1

120 cm ; intermolecular symmetric stretching mode
120 cm-1 ；対称伸縮; intermolecular bending98mode
cm-1

-1

90 cm

mode. These results clearly
indicate that the 120 cm-1
vibration is the promoting
mode of DPT reaction in the 7AI dimer. Thus, the dynamical
features of the proton-transfer
reaction were elucidated forthe first time. The issues on
the mechanistic nature of the
proton transfer in the 7azaindole

dimer

have

subsequently been the subjects

Wavenumber /cm-1of extremely intensive studies

Fig. 3 Fluorescence excitation spectrum of jet-cooled 7 Al dimer obtained by monitoring
visible emission of tautomer. The spectrum corresponds to the action spectrum of the DPT-1reaction. The numbers inserted with arrow are the bandwidths (fwhm) in cm .

and explored in depth by
means

of

experiments.

theories

and

9

6. Research at Institute for Molecular Science
In the autumn of 1988, I moved to Okazaki as associate professor at Institute for Molecular Science. I had an
opportunity to do some extended reading journal articles, searching for possible topics for starting the newresearch on the gas-phase clusters. After the recharging days in the IMS library, one of the topics I chose was
the spectroscopic study on atomic clusters of semiconductor elements. The study on the physical properties ofthese clusters were quite limited, because the small semiconductor clusters have high ionization potentials andit was difficult to ionize by a commercial laser. I also re-recognized that the clusters containing metal ions andsolvent molecules have extensively been studied for more than two decades by several research groups, to bridge
the gap between the gas and condensed phases. However, these studied were mostly concerned with thethermodynamic properties with high-pressure mass spectrometry and collision induced dissociation
experiments, and the structural information was based mainly on the theoretical calculations. I expected that the
spectroscopic studies on the clusters consisting of metal ions with polar solvent molecules may provide us rich
structural and energetic information on the stepwise solvation processes in finite clusters. Moreover, themolecular beam method coupled with the laser vaporization technique allows us to produce the solvated metal
ions of any element in the periodic table and therefore, a new field of cluster chemistry could emerge. In thenext paragraphs, I present the brief summaries of the photoionization studies on semiconductor clusters andsome of the pioneering works on solvated metal atoms (ions) related not only to solvated electrons, but also to
the redox reactions of metal ions in solvent clusters. The latter works were conducted in collaboration with Dr.
Fuminori Misaizu (Tohoku University), and the theoretical groups of Dr. Suehiro Iwata (Keio University) andDr. Kenro Hashimoto (Tokyo Metropolitan University).
7. Photoionization studies on semiconductor clusters
The physical properties of small silicon clusters have been an extremely active area of both experimental andtheoretical studies because of its importance in fundamental as well as applied sciences. The motivation for thestudies is to elucidate what happens to the physical and chemical properties of a bulk material as dimensions
approach interatomic distances and to determine whether there are any special clusters with unique properties.
Especially, information on the electronic structures is indispensable to characterize the small silicon clusters. It
also becomes important after the discovery of emissive nanometer-scale silicon clusters. Studies of theelectronic structures of Sin were hampered by high values of the IPs and also by the very low volume density ofsiliconmolecular

produced

in

the

laser

vaporization source. Photoelectron spectroscopy

n=23
bulk

clustersofmolecular

negatively

chargedclustersandthephotoionization experiments of neutral clusters
have been conducted to gather information on
the growth of the electronic level structure of Sin,,but the clusters examined were still limited tosmall size.
To overcome these situations, we carried out
the photoionization threshold measurements for
Sin

Fig. 4 Ionization potentials of Sin, n = 2 - 200, plotted vs n

-1/3

and thewith

anunprecedentedly

widephotoionization energy (5.0-8.5 eV) using an IP

bulk ionization energy and work function for Si(111). The solid line

bracketing. A high­output vacuum ultraviolet

is the prediction of a classical conducting spherical droplet model.

(VUV)

laser

was

developedasthephotoionization light source in the energy above
6.42 eV (ArF excimer laser), in addition to the second harmonic of an excimer-pumped dye laser below thisenergy. We adopted the anti-Stokes shifting technique to generate radiation down to 146 nm, because thismethod may enable us to generate the highest energy output in VUV with a combination of commercial lasers.
Figure 4 shows the size-dependence of IPs of Sin, n =2-200.10 The major maxima at the cluster sizes of 10 and
20 atoms and a large gap in IPs between n = 20 and 22 are found. Figure 4 shows that the IPs decrease smoothly
up to 5.17 eV for the cluster size of 25< n < l00. For larger clusters with Si atom of n = 100 - 200, IPs does
decrease to 5.17- 4.99 eV, which are slightly higher than the bulk work function (4.85 ± 0.02 eV) determinedby photoemission threshold measurements. The discrepancy of IPs between clusters and bulk were attributable
to the difference in the distribution of surface states for these phases.
We also extended to the studies for Gen (n=2 – 57) and Snn (n=2 – 41) in the energy region of 5.0–8.8 eV.11
The IPs of the clusters with fewer than 11 atoms were found to exhibit the size dependence very similar to thatfor Sin including the major maximum at 10 atoms, which implies the similarity in the geometrical and electronic
structures for these clusters. Based on the theoretical results in the literature, we discussed the size dependence

of IPs for small germanium and silicon clusters in relation to the compact metal-like structures. We found theremarkable difference in the size dependence of the IPs for the medium-size Sin , Gen , and Snn clusters. Gen(n>12) clusters were found to exhibit the large gap in IP at around 20 atoms, similar to that found for Sin. On
the other hand, the IPs of large tin clusters decrease slowly without a gap. The large IP gaps for the Sin and Gen
clusters were attributed to the possible existence of a structural transition, reported in the mobility measurements
for the cluster ions. The IPs of semiconductor clusters were systematically determined for the first time ever,and they become the reference values to elucidate the accuracy of the theoretical calculations of the clusters forthe last decades.
8. Spectroscopic studies on solvated electron in finite-size clusters
Solvated electrons in polar solvent have been the subject of intensive studies for the last decades. Recent
advances in laser spectroscopy permit one to obtain unique information on the dynamical aspects of thesolvated electron, especially on the early stage of solvated-electron formation in solution. Despite these efforts,
the microscopic structure and dynamics of the solvated electron in solution remain unresolved. One of themost intriguing and difficult issues may be the many-body interaction between a diffuse electron and solvent
molecules. It is difficult to fully understand the solvation dynamics of the electron in polar solvent without
detailed knowledge on the nature of the diffused electron. On the other hand, these issues are significantly
simplified in clusters, in which the fundamental interaction in solution may be retained. The cluster study
enables us a direct comparison between the experimental and theoretical results and will provide information on
the intrinsic nature of the solvated electron. From this point of view, we carried out a series of pioneeringexperiments on solvated electron in
n

20

10

5

3

finite-size

1

6

clusters

photoionization
Li (H2O)n5.39 eV
5.14 eVCs (H2O)n5

thephotoelectron

spectroscopies.
The polar-solvent clusters containing
neutral alkali atoms are the prototype

Na (H2O)nIP/ eVandusing

of a dilute alkali metal solution, in
which solvated electrons have been

4

3.89 eVinvestigated extensively, and may serve
as a good model for linking the
microscopic

3

3.1 eV

properties

withmacroscopic ones of alkali metalsolvent systems. In these clusters, thevalence electron of an alkali metal

2
0

0.2
(cluster size)

0.4-1

atom is expected to be transferred to a

Fig. 5 Ionization potentials (IPs) of Li(H2O)n (○; ref. 13), Na(H2O)n (◊;ref.12), and Cs(H2O)n (□; ref. 13)
clusters for n ≥ 4 are 3.1 ± 0.05eV.

-1/3

plotted as a function of n

. IPs of thesesolvent cluster with sufficiently large n,
and the ground state is expected to beof an ion-pair character as in the case ofbulk fluids. To find this transition, Hertel’s12 and our groups13 investigated the photoionization processes of theclusters consisting of alkali metal atoms of Li13, Na12 and Cs13 with ammonia and water molecules. Figure 5
shows the size-dependence of ionization potentials (IPs) of Li(H2O)n, Na(H2O)n , and Cs(H2O)n. We found therapid converge of IPs at n = 4 (3.2 eV), independent on the metals, to the estimated photoelectric thresholdof ice. On the other hand, the IPs of metal-ammonia clusters decrease monotonously for n as large as 40; its
limiting values again agree with the bulk photoelectric threshold of liquid ammonia at ca. 1.4 eV. These
characteristics in IPs were analyzed in terms of the stabilization of an ion-pair state correlating with thesolvated-electron state in bulk solution. Several theoretical groups have also made efforts to correlate the IP
behaviors with the solvation state of alkali atoms. However, because the experimental data were limited only
to the IP measurements, the microscopic solvation process of alkali-metal atoms in clusters has not yet been
fully understood.
To get further insight into the electronic structure of solvated alkali atoms, we constructed a magnetic-bottle type
2

S-1S

2

photoelectron spectrometer and studied the photoelectron spectra of theclosed shell anions, M-(H2O)n and M-(NH3)n (M = Li, Na), produced

P-1S
n =0

by a laser vaporization technique coupled with a supersonic
expansion method. Because the final states of the photoelectron

n =1transitions of the anion clusters are the ground and excited states ofneutral clusters, the photoelectron spectra as a function of size

n =2

provide information on how the electronic structure of alkali atom inboth the neutral ground and excited states changes with the solvationn =3

number, n.
The photoelectron spectra of Na-(NH3)n and Li- (NH3)n indicate thatn =4

the electronic structure of alkali atoms in ammonia clusters areextensively changed with the cluster size. Especially, in the case ofn =5

Li- (NH3)n, the 32S- and 22P-type states of clusters were dramaticallystabilized and almost become degenerate with the ground state (22S)n =6

for n≥ 10.14 This trend in PES is consistent with the theoretical resultsthat the SOMO electron density of the alkali atom is delocalized over

n =8
0

1

2

3

and beyond the solvent molecules with increasing n. These findings
4Electron binding energy/ eVsuggest that the photoionization process of the larger clusters
corresponds to the ejection of an electron over the delocalized region-

Fig. 6 Photoelectron spectra of Li (D2O)n(n = 0 - 10), collected using aphotodetachment energy of 3.50 eV. In
order to improve the mass separation,
D2O is used instead of H2O.

of solvent molecules. The observations that the Li-, Na-, and Csammonia clusters have the same IP value for n ≥ 5 support the above
conclusions. The characteristics of the PES exhibit the early stage ofthe spontaneous ionization of the alkali-metal atom in ammonia

clusters to form the one-center (Rydberg like) ion-pair state.
As for the alkali atom-water clusters, we had also examined the PESs of closed shell ions Li-(H2O)n and Na(H2O)n. Because of the large difference in the geometrical structures of the anion and neutral states for Na-

(H2O)n, we could not obtain information on the electronic structure of the neutral clusters. On the other hand,the anomalous red-shift of the Li (2S) – Li-(1S) - type transition was found in the PES of Li-(H2O)n for n ≤ 4,
and as shown in Fig. 6,for n ≥ 5 the spectral shift together with the sudden increase of the bandwidth wereobserved.15 The large solvation energy of the neutral clusters, compared with the corresponding energy of theanion clusters, was ascribed to the increase in ionic character resulting from the spontaneous ion pair formation,
Li+ -- (H2O)n-. Through these studies, we could experimentally demonstrate for the first time the early stage ofsolvated-electron formation from alkali atoms in small ammonia and water clusters.

9. Spectroscopic studies on solvation processes of alkaline-earth metal ion in water clusters
The redox reaction process of metal ions related to the solvated-electron formation has been one of the central
issues in solution chemistry, and has a long history in inorganic chemistry. In most of the previous studies, themolecular level of analysis for solvation of the atomic ions had to be guessed from the properties of bulk
solvation, and therefore, the solvation process was not fully elucidated. Advances in molecular beam techniques
allow us to create size-controlled hydrated metal ion clusters. Thus the solute-solvent interaction can becontrolled, and the laser-based gas phase spectroscopic techniques can be applied to examine in details theeffects of solvation on metal ions, and to follow its induced reactions with solvent. Moreover, because theclusters are much simpler than the bulk solution systems, further clarification becomes possible by performing
the direct theoretical calculations of the target systems. We carried out for the first time the spectroscopic studies
to reveal the electronic structures, geometrical structures, and oxidation reactions of hydrated monovalent metal
ions, Mg+(H2O)n and Ca+(H2O)n, produced by multiple collisions between the laser-vaporized atomic ions andthe water clusters. With a series of papers, we successfully developed a new field of the gas-phase metal-ion
chemistry in finite size clusters.16(1) Spectroscopy on hydrated metal ions: Geometries and electronic structures
Hydrated metal ions such as Mg+(H2O)n was synthesized by expanding the laser-vaporized alkaline-earth
metal ions with a method with a water vapor seeded in high pressure He. A reflection-type time-of-flight (TOF)
mass spectrometer was utilized to examine the photodissociation products as well as the dissociation spectrumof mass-selected cluster ions. During the photodissociation process of Mg+(H2O)n, not only the evaporation of
one or more water molecules (1) but also the photoinduced chemical reaction to produce hydrated MgOH+ ions(2) are found as follows;
M+(H2O)n → M+*(H2O)n →M+(H2O)m + (n-m)H2O→ MOH (H2O)m + H ++(1)(n-k-1)H2O(2)+Figure 7 shows photodissociation spectra of Mg (H2O)n, n=1-5, obtained by taking the total yield of fragment
ions as a function of photolysis wavelength.18 The spectrum of n=1 consists of an intense band at 30500 cm-1
with a weak shoulder at 28300 cm-1, and another band at 38500 cm-1, which locate close to a Mg+ resonanceline. These bands were assigned to the transitions to 2B1(p πx), 2B2(p πy), and 2A1(pσ), respectively. For n=2, a
new overlapped band at 30500 cm-1 was observed in addition to the band at 25000 cm-1. The dissociation

spectrum for n = 3 consists of two main bands andexhibits the smallest band width; the higher-energy
band is observed at about 28500 cm-1 which isshifted by ca. 2000 cm-1 from that for n = 2.
However, the lower energy peak does not shift
appreciably by addition of the third water molecule.
Small redshifts of these bands from those for n = 3
were observed for n = 4 and 5, and a weak shoulder
appears at ca. 17000 cm-1 for n = 5. The spectra
were well reproduced by the ab initio CI
calculations. In Fig. 7, the calculated most stablestructures are also inserted.17 The spectra for thisentire series of clusters show significant redshift
relative to the atomic resonance lines of Mg+ near
35700 cm-1 and exhibit the stepwise shell formation
around the Mg+ ion showing the clear evolution of+Fig. 7 Photodissociation spectra of Mg (H2O)n with n = 1 to n
= 5. These are obtained by taking into account the total yieldof the fragment ions. The intensities of the spectra aresolvation shell closing at n=3. Based on thetheoretical calculations, the new band observed innormalized at their peak positions. The calculated most stable

the lowest energy region for n=5 was assigned to a

structures cited from ref. 16 are inserted for each size.

(4 + 1) isomer in which four water molecules
coordinate directly to Mg+ from the same side andthe 5th water molecule locates in the second hydration shell. The rapid decrease of the transition energy byincreasing the coordination number may imply the progress in oxidation of the metal ion further. In the spectraof Ca+(H2O)n, similar and much more profound shifts were observed.19 From these series of works, therelationship between the hydration structure and the oxidation process was elucidated for the first time.
(2) Size dependence of oxidation reactions of metal ions in water clusters.
To gain more insight into the effect of hydration structure on the oxidation reaction of metal ions, we
examined the reactions of the alkaline-earth metal ions M+ (= Mg+ , Ca+) with the (H2O)m and (D2O)m clusters
using a simple cross beam apparatus. Figure 8a shows a typical time of flight (TOF) mass spectrum of thenascent cluster ions produced by the collision of the Mg+ ions with water clusters.20 Both Mg+(H2O)n and
MgOH+(H2O)n-1 ions were produced by the reactions as follows,
Mg+ + (H2O)n → Mg+(H2O)m + (n-m)H2O(1)→ MgOH (H2O)m + H + (n-m-1)H2O+(2)Figure 8b shows the relative abundances of Mg+(H2O)n and MgOH+(H2O)n-1 determined from the mass spectrum.
These cluster ions are produced with characteristic size distribution: For 1 ≤ n ≤ 5 and n ≥15, the Mg+(H2O)nions are dominantly produced. In contrast, MgOH+(H2O)n-1 are exclusively observed for 6 ≤ n ≤ 14. The results
indicate that the product ions switch rapidly at two critical cluster sizes such as n=5 and 15.

Based on these results as well as the results on the
1

5

20

successive calculated hydration energies of MgOH+,

Mg+ (H2O) n

the origin of the first product switching for n ~5 was

15

MgOH+ (H O) n

Mg+ (H2 O)n
5

10

2

15

ascribed to the difference in the successive hydrationenergies of M+ and MOH+; the product, MOH+(H2O)n+1+ H lowers much faster in energy than M (H2O)n as

Ion intensity

the cluster size increase, and it becomes the groundstate of the system for n ~5.
400

200
300
Mass m/e

100

As for the second product switching for n ~15, theorigin is not self-evident. We proposed two possible
mechanisms such as the participation of the Rydberg-

Mg+(H2O) n
MgOH+(H2O) ntype ion pair state M2+(H2O)n- and the formation of the

Mg+(H2O) n

new reaction product such as MgOH·H3O+(H2O)n-2.
The former mechanism is based on the results for thephotodissociation spectra of Ca+(H2O)n and is an

1

5

10

15

20

cluster size
Fig. 8(a) TOF mass spectrum of the product ions for the+reaction of Mg with water clusters in the cluster source. (b)interesting candidate in relation to the solvation
process of metal ion in bulk water. The lattermechanism stems from the chemical analogy. At+

Relative abundances of the product ions for the Mg - (H2O)n+reactions. The bars in the figures correspond to Mg (H2O)n+(filled) and MgOH (H2O)n (open), respectively. The
products switch at two cluster sizes; n = 5 and n = 15.

present, the former mechanism is considered to bemuch plausible to understand the switching; however
we could not rule out the latter mechanism within thepresent experimental data. The present study was thefirst experimental work which unveil the microscopic solvation dynamics of metal ions accompanying the redox
reactions in the gas phase clusters.21
10. Stability and solvation process of hypervalent radical in small clusters; NH4NH4 is a typical hypervalent Rydberg radical, which is isoelectronic with an alkali atom, and readily
formed through an attachment of hydrogen atom to ammonia molecule. This radical is also produced throughthe recombination of an electron with RNH3+ ion, which is ubiquitous in solution, and considered to be an
important intermediate in many reactions including the reactions observed in biological systems. In order toelucidate the dissolved state in solution and its role in the reaction as an intermediate, we examined the ionization
potentials (IP), absorption spectra, and the dynamics of the formation processes of NH4(NH3)n clusters. The
radical clusters were produced through the photodissociation of ammonia clusters, using the nanosecond andfemtosecond pump-to-prove experiments. From these studies, we clarified for the first time the stability andelectronic structure of NH4 in ammonia clusters. It was found that the isolated NH4 dissociates into NH3 + H
with a lifetime of 13 ps and it is substantially stabilized in ammonia clusters; the lifetimes of NH4(NH3)n increase
to longer than 3 µs for n>1.22 To clarify the mechanism of the stabilization, we determined the IP of these clusters.
Combining the IPs for small clusters with the literature values of the successive binding energies for NH4+(NH3)n,we estimated the binding energies of the ammoniated radicals. For NH4 (NH3), the binding energy was estimatedto be 0.34 eV, which is much larger than the dissociation energy of ammonia dimer (< 0.12 eV). Thus, theextensive stabilization of NH4 in the clusters was found to be due to the large solvation energy of this radical
comparing with the binding energy of NH3 itself.
Figure 9 shows the results of IPs determined for n up to 35, which are plotted as a function of (n+1)-1/3 byassuming a spherical droplet model.23 In this figure, the previously-determined IPs of Cs(NH3)n are also plotted
50

n

10

for comparison. The IPs of NH450(NH3)n decrease rapidly from n=3 to
4 and then decrease further gradually

5 .0

as the cluster size increase. The rapid
decrease in IPs from n=3 to 7 was

IP / eV

4 .0

4ascribed to the large stabilization of
the ionic state with respect to the

17

3 .0

neutral ground state by clustering.

35

The observations, that the trend in
IPs changes at n~17 as seen in Fig. 9

2 .0

and the IPs for larger clusters

1 .0

Liq. NH3

NH4(NH3)n≈1.37eVCs(NH3)ndecreasealmostlinearlywithdecreasing (n+1)-1/3, were explainedby the filling of the second solvent
shell in analogy with the case of

0.0
Fig. 9

0.2

0.4
0.6
0.8
-1
1
/
(cluster size) ∝ (n+1) 3

1.0

Ionization potentials of NH4(NH3)n (n = 0 - 35) plotted vs (n+1)

NH4+(NH3)n; in the latter clusters, thesecond solvent shell is known to be

-1/3

.

The IPs of Cs(NH3)n (ref. 13) are plotted for comparison. The result of theclosed

with

ca.

20

ammonia

least-squares fitting for n = 15-35 (straight line) gives an extrapolated value

molecules. Although the feature of

as 1.37 eV, which agrees with the photoemission threshold of liq. NH3.

IPs for the small NH4(NH3)n clusters
is slightly different from that forCs(NH3)n, the trends in IPs for the large clusters are quite similar as seen in Fig. 9; these systems give the same
limiting value as ca. 1.4 eV. In the separate work, we also measured the electronic absorption spectra of the 3p 3s-type transitions of NH4(NH3)n (n = 1-8).24 The results show a drastic decrease of the excitation energy for n≤ 4 and no appreciable change for n ≥ 5. These changes in the transition energies are very similar to those of the2

P - 2S energy separations in the PES of Na-(NH3)n.14 From the large spectral change as well as the above similar

size dependence in IPs, we concluded that the NH4 radical is spontaneously ionized in relatively small ammonia
clusters and possibly in water clusters as well. These findings on the solvation state of NH4 might be true forthe ammonium radicals created in the widespread reactions of biological systems.
11. Research at Kobe University
In the summer of 1995 just after the earthquake, I moved to Kobe as professor in the chemistry department

at Kobe University. I shipped all apparatus constructed at IMS to Kobe and rebuilt them to establish the newlaboratory. Since we had just started the photoelectron works at IMS, we continued the studies on thephotoelectron spectroscopy of negatively-charged alkali atoms (and its clusters) solvated with ammonia andwater molecules. We also extended the photoionization study of silicon clusters to Gen and Snn. After a few
years of intensive research, I conceived a new project to use an electrospray ionization (ESI) source in thephotodissociation spectroscopy. At that time, this technique was limited only to be used in an ion mobility
measurement of gas-phase proteins by M. F. Jarrold, except for the basic mass spectroscopy. With the ESI sourcein the photodissociation apparatus I expected we could start a new laser spectroscopy on any biologicalmolecular ions such as peptides and proteins. The first photodissociation apparatus with the ESI source wedeveloped was a tandem mass spectrometer with an octapole ion beam guide, where the laser beam isintroduced to interact with the ions.24 We could study biological molecules at room temperature. To carry out
a temperature dependent experiment, we also developed the machine adopting a temperature-variable 22-pole
ion trap so that we could cool the ions down to 20 K.25
During these studies, I have also been strongly felt the importance of a new method to detect magnetic

resonance for the gas phase ions. On one day I read a paper on ion cyclotron resonance (ICR) mass
spectroscopy and found its close similarity to a Fourier transform NMR spectroscopy. This finding inspired
me to design a new apparatus, in which an ICR cell is placed in tandem with a NMR cell in a bore ofsuperconductive magnet so that NMR can be detected for mass selected ions. Since the ICR technique is welldeveloped and commercially available, I spent many hours to calculate ion trajectories for establishing themechanism of the NMR detection of the trapped ions in a Penning-trap-type cell. After several trials, I
conceived the mechanism such as a Stern-Gerlach type experiment in the magnet, which is described inparagraph 13. In the next paragraphs, I present the pioneering works on the spectroscopy of solvated biologicalmolecules using the ESI-photodissociation apparatus and the study on the gas-phase NMR spectroscopy.
12． Spectroscopies on hydrated biological clusters: Structures and energetics.
The interaction of water with peptides and with proteins is of central importance in understanding biologicalsystems. The clusters composed of water and these biological molecules are the good target systems for themodeling, and the laser-based gas phase spectroscopic techniques can be applied to examine in details the effects
of solvation on these solutes. The gas phase spectroscopic measurements of clusters, at various degrees ofaqueous solvation, give information on the energetics and structures that are primarily caused by the intra- andinter molecule H-bonds. But, because these materials are nonvolatile and it is difficult to prepare their hydrated
clusters, the spectroscopic study of the biological molecular systems had been very limited. To overcome thedifficulty, we developed for the first time a photodissociation spectrometer with an electrospray ionization
source for biological molecules. Using this apparatus, we investigated the reactions and structures of biologicalmolecules, for example, hemine (the heme group of hemoglobin), and its solvated clusters.24 We also examined
the photoinduced reactions of multiply-charged cytochrome c ions, which was initiated by the electronic
excitation of heme group. By following the metastable decay processes of hydrated TrpH+, the binding energiesof the hydration were estimated.

Structures of polypeptides are one of the important factors in the characterization of physical and chemical
properties of biological molecules. There are many conformers which may coexist in the experimental beams.
They are at local minima in the potential energy landscape, and conformational fluctuations possibly play
important roles in various functions of biological molecules. To examine microscopic aspects of structuralfluctuations and reactivities of clusters containing biological molecules, it is necessary to perform spectroscopic
measurements of gas-phase clusters at various temperatures. However, the experimental studies on the gasphase clusters with a well-defined temperature or at least under controlled temperatures had been limited
because of difficulties in confining gas-phase clusters under controlling temperatures. To perform aspectroscopic study of gas-phase cluster ions as a function of temperature, we constructed a photodissociation
spectrometer containing the temperature-controlled multipole ion trap and a spray ionization source, and studied
the structure and reactivity of cold protonated peptides.
Figure 10a shows the UV photodissociation+

spectrum of TrpH+ at 21 K obtained by monitoringa. TrpH–1

235 cm

21 K

the fragment ion m/z 188 as a function of excitation

0energy.25 The broad band at 35100 cm–1 is attributed

0 0 Trp-1

to the S1–S0 band origin of TrpH+. The absorption

Relative Intensity

34873 cmof TrpH+ is in the same energy range as the S1–S0transition of neutral Trp (red bar).

+b. Trp-GlyH

The resultshows that the protonation does not affect the

21 Kelectronic structure. Figure 10b shows a UV
photodissociation spectrum of Trp-GlyH+ at 21 K
obtained by monitoring the fragment ion m/z 245.

c.

The spectral feature of Trp-GlyH+ is very similar to+

Ala-TrpH

that of TrpH+. Based on the theoretical calculations,

22 K

the distance between the NH3+ group and the indole
ring is rather long in TrpH+ and Trp-GlyH+, becauseof the geometrical constraint for a Cα–Cβ bond. Fig.

32.0

32.5

32

33.0

33.5

34.0

34.5

35.0

33
34
3
–1
Wavenumber
/10
cm
36

35

35.5

at 22 K obtained by monitoring the fragment ion+

Fig. 10 UV photodissociation spectra of (a) TrpH , (b) Trp++

-1

GlyH , and (c) Ala-TrpH . The peak at 35100 cm is the S1-S0+

band origin of TrpH broaden due to a rapid photodissociation
reaction in the S1 state.

10c is the photodissociation spectrum of Ala-TrpH+
m/z 205. The broad band shifts to the red by ~2000
cm-1 with respect to the S1–S0 origin of TrpH+ and
Trp-GlyH+. The theoretical calculations show that
the NH3+ group in the most stable Ala-TrpH+

conformer is close to the π cloud of indole. Thus, the significant red shift in the UV spectrum of Ala-TrpH+ wasrelated to the structure in which the NH3+ group interacts strongly with the π cloud of indole. We also examined
for the first time the temperature effect on the UV spectrum of Ala-TrpH+ and observed the thermally-induced
conformational change.

13. Development of gas-phase NMR spectroscopy
Nuclear magnetic resonance (NMR) technique is widely used for the physical and chemical analysis ofvarious materials in liquid and solid phases. Although it has been well established for analyzing materials in
1

5

3

(A)

2

4

condensed

phase,

aninherent

problemofcondensed phase NMR is

8 .4

92.7
1 .6

Laser

its low sensitivity. Hence

6
NMR celllimitations come from the(B)
B (T)field (T)magnetic

Field of superconductive magnet

Gradient field (9.4 T – 3.1 T)

requirements of a large
amount of sample and, also,

10 10

the required purification
5 5
0 0

sometimes

limitstheanalysis. In contrast, mass
-500
-500

00

500
500
10001000
position (mm)spectrometric techniques
Position (mm)Fig. 11 Schematic of gas-phase NMR apparatus:
can often overcome these
1. Ion source with traveling potential well (TPW) decelerator.
problems, and various
2. Front and back gates. 3. 9 T and 3 T Rf coils. 4. MCP
5. Mesh electrodes for velocity selection
types of mass spectroscopic
6. velocity dispersion compensator.

techniques

have

been

developed and are widely used in broad research fields because of their extremely high sensitivity and excellent
selectivity. However, mass spectrometry essentially only gives information on the mass number, and for further
chemical information computer simulations are often required. Under these circumstances, a new extension of
NMR technique to gas-phase molecular ions becomes increasingly important for both fundamental and appliedsciences.
In order to overcome the above problem for the structural analysis of mass-selected ions, we proposed a
new method of magnetic resonance acceleration (and/or deceleration) to detect NMR signals of trapped ions ina high magnetic field. This method is a new extension to mass-selected ions of the Rabi technique26 for neutrals.
We designed and constructed the apparatus on the basis of the present method as shown in Fig. 11. The NMR
cell was installed in superconductive magnet with the strong magnetic field gradient and works as a Penningtype trap. To facilitate the detection of a weak NMR signal, the cell consists of two trapping electrodes and two
RF coils at both ends in order to confine the mass-selected ions in magnetic field and allow multiple magnetic
interactions by resonantly flipping a nuclear spin synchronized with a shuttle motion of ion packet.27
We also developed the formation and manipulation techniques for cold ions, which are the key to facilitate
the detection of a weak NMR signal for the gas phase ions. We examined the deceleration and bunching of theion packet generated by the photoionization of the supersonically cooled TMA(trimethylamine ) using a TPW
decelerator invented by ourselves. Ion packets with a center velocity of less than 150 m/s are generated. To cool
down the ion packets, we developed a slicing technique using the mesh electrodes. By cutting out the bunched
ion packet, we can reduce the velocity distribution width to 3.9 m/s FWHM, which corresponds to thetemperature of 33 mK.28 The ion packet is further cooled down below 1 mK using a newly developed techniquesuch as a velocity dispersion compensation. These results on the basic performance of the present apparatus
suggest that the first NMR signal for polyatomic ions will be detected in near future.

Acknowledgements

Firstly, I would like to express my sincere gratitude to Prof. Saburo Nagakura. who was my supervisor in DC
course, for his continued encouragement.
I heartily thank Dr. Koji Kaya and Dr. Suehiro Iwata, who are my senior associates in Prof. Nagakura'slaboratory, for their collaborations, encouragements and more over for their timely supports. I would also liketo thank Dr. Fuminori Misaizu, Dr. Kenro Hashimoto, Dr. Shinji Nonose, and Dr. Haruki Ishikawa for their nicecollaborations. My thanks also to the Equipment Development Center of IMS for continued technical supports.
This work has been supported by the Grant-in-Aid for Scientific Research from the Ministry of Education,
Culture, Sports, Science, and Technology (MEXT) of Japan and partially by the research grant from the Japan
Science and Technology Agency.
References(1) Iwata, S.; Fuke, K; Sasaki, M.; Nagakura, S.; Otsubo, T.; Misumi, S. J. Mol. Spectrosc. 46,

1―15 (1973).
(2) Fuke, K.; Ueda, M.; Itoh, M. J. Am. Chem. Soc. 1983, 105, 1091―1096.
(3) Duncan, M. A.; Dietz, T. G.; Smalley, R. E. Chem. Phys. 1979, 44, 415―419.
(4) Dietz, T. G.; Duncan, M. A.; Powers, D.E.; Smalley, R. E. J. Chem. Phys. 1981, 74,
6511―6512.
(5) Fuke, K.; Saito, T.; Kaya, K. J. Chem. Phys. 1984, 81, 2591― 2598 .
(6) Fuke, K.; Kaya, K. Chem. Phys. Lett. 1983, 94, 97―101.
(7) Twier, T. S. Ann. Rev. Phys. Chem. 1996, 47, 205―241.
(8) Fuke, K; Kaya, K. J. Phys. Chem. 1989, 89, 614―621.
(9) Douhal, A.; Kim, SK; Zewail, AH. Nature, 1995, 378, 260―263.
(10) Fuke, K.; Tsukamoto, K.; Sanekata, M.; Misaizu, F. J. Chem. Phys.1993, 99, 7807 ―7811.
(11) Yoshida, S.: Fuke, K. J. Chem. Phys. 1999, 111, 3880 ― 3890.
(12) Hertel, I. V.; Huglin, C.; Nitsch, C.; Schulz, C. P. Phys. Rev. Lett. 1991, 67, 1767 ―1770.
(13) Misaizu, F.; Tsukamoto, K.; Sanekata, M.; Fuke, K. Chem. Phys. Lett. 1992, 188, 241―246.
Takasu,R.; Misaizu, F.; Hashimoto,K.; Fuke, K. J. Phys. Chem. A 1997, 101, 3078―087.
(14) Takasu, R.; Hashimoto, K.; Fuke, K. Chem. Phys. Lett., 1996, 258, 94 ―100.

(15) Takasu, R.; Taguchi, T.; Hashimoto, K.; Fuke, K. Chem.. Phys. Lett, 1998 290, 481―487.
(16) Beyer, MK. Mass Spectrom. Rev, 2007, 26, 517―541.
(17) Watanabe, H.; Iwata, S.; Nakamura, H.; Hashimoto, K.; Misaizu, F.; Fuke, K. J. Am. Chem.
Soc. 1995, 117, 755― 763.
(18) Misaizu, F.; Sanekata, M; Fuke, K; Iwata, S. J. Chem. Phys. 1994, 100, 1161―1170.

(19) Sanekata, M.; Misaizu, F.; Fuke, K. J. Chem. Phys. 1996, 104, 9768 - 9778.
(20) Sanekata, M.; Misaizu, F;. Fuke, K.; Iwata, S.; Hashimoto, K. J. Am. Chem. Soc. 1995, 117,
747―754.
(21) Fuke, K., Hashimoto, K.; Iwata, S. Adv. Chem. Phys. 1999, 110, 431―523.
(22) Fuke, K.; Takasu, R. Bull. Chem. Soc. Jpn., 1995, 68, 3309―3318.
(23) Fuke, K.; Takasu, R.; Misaizu, F. Chem. Phys. Lett. 1994, 229, 597―603.
(24) Nonose, S.; Tanaka, H.; Okai, N.; Shibakusa, T.; Fuke, K. Eur. Phys. J. D, 2002, 20, 619―626.

(25) Fujihara, A.: Matsumoto, H.; Shibata, Y.; Ishikawa, H.; Fuke, K. J. Phys. Chem. A, 2008,
112, 1457―1463.
(26) Rabi, I. I.; Millman, S.; Kusch, P.; Zacharias, J. R. Phys. Rev. 1939, 55 526―535.
(27) Fuke, K.; Tona, M.; Fujihara, A.; Ishikawa, H. Rev. Sci. Instrum. 2012, 83, 085106-1―8.
(28) Fuke, K. ; Ohshima, Y.; Tona, M.; Hyperfine Interactions, 2015, 236(1), 9-18.

Publication list (2018)
Kiyokazu Fuke
Original papers(1) "Electronic Spectra and Electronic Structures of (2,2)-Paracyclophane and Related
Compounds", S. Iwata, K. Fuke, M. Sasaki, S. Nagakura, T. Otsubo, and S. Misumi, J.
Molecular Spectroscopy, 46, 1 - 15 (1973).
(2) "Polarized Absorption Spectra of the Hydroquinone and 1,4-Dimethoxybenzene Crystals
in the near and Vacuum Ultraviolet Regions", K. Kaya, K. Fuke, and S. Nagakura, Bull.
Chem. Soc. Japan, 47, 438 - 441 (1974).
(3) "Polarized Reflection and Absorption Spectra of the (2,2)-Paracyclophane",K. Fuke and
S. Nagakura, Bull. Chem. Soc. Japan, 48, 46 - 49 (1975).
(4) "Two-photon Absorption Spectrum of (2,2)-Paracyclophane",K. Fuke, S. Nagakura, andT. Kobayashi, Chem. Phys. Lett. 31, 205 - 207 (1975).
(5) "The Polarized Reflection and Absorption Spectra of Perylene Crystals in Monomericand Dimeric Forms", K. Fuke, K. Kaya, T. Kajiwara, and S. Nagakura, J. Molecular
Spectroscopy, 63, 98 - 107 (1976).
(6) "Electronic Structure and Spectra of Acrylic Acid in the Vapor and Condensed Phases",H. Morita, K. Fuke, and S. Nagakura, Bull. Chem. Soc. Japan, 49, 922 - 928 (1976).
(7) "Rydberg Transitions of Aniline and N,N-Dimethylaniline", K. Fuke and S. Nagakura, J.
Molecular Spectroscopy, 64, 139 - 146 (1977).
(8) "Charge-Transfer Character in the Intramolecular Hydrogen Bond: Electronic Structures
and Spectra of Hydrogen Malate Anion and Related Molecules", H. Morita, K. Fuke, and
S. Nagakura, Bull. Chem. Soc. Japan, 50, 645 - 649 (1977).
(9) "Absorption and Magnetic Circular Dichroism Spectrum of Allene",K. Fuke and O.
Schnepp, Chem. Phys. 38, 211 - 217 (1979).
(10) "The Magnetic Moment of the 1E1u N-V State of Benzene and its Methyl Derivatives",
K. Fuke, A. Gedanken, and O. Schnepp, Chem. Phys. Lett., 67, 483 - 486 (1979).
(11) "Direct Observation of Intramolecular Anthracene Excimer in 1,3-Dianthryl-propane",M.
Itoh, K. Fuke, and S. Kobayashi, J. Chem. Phys. 72, 1417 - 1418 (1980).
(12) "Direct Observation of Singlet Oxygen by a Thermal Lensing Technique", K. Fuke, M.
Ueda, and M. Itoh, Chem. Phys. Lett. 76, 372 - 374 (1980).
(13) "Two-photon Absorption Spectrum of Trans-stilbene: Trans-Cis Photoisomerization via
Upper 1Ag State", K. Fuke, S. Sakamoto, M. Ueda, and M. Itoh, Chem. Phys. Lett. 74,
546 - 548 (1980).
(14) "Tryptophan Fluorescence of Human Hemoglobin. I: Significant Change of Fluorescence
Intensity and Lifetime in the T-R Transition", M. Itoh, H. Mizukoshi, K. Fuke, S.
Matsukawa, K. Mawatari, Y. Yoneyama, M. Sumitani, and K. Yoshihara, Biochem.
Biophys. Res. Commun. 100, 1259 - 1265 (1981).
(15) "A Thermal Lensing Study of a Photolysis of Di-t-Butyl-Peroxide", K. Fuke, A.
Hasegawa, M. Ueda, and M. Itoh, Chem. Phys. Lett. 84, 176 - 179 (1981).
(16) "Lifetime of Singlet Oxygen and Quenching by NaN 3 in Mixed Solvent", N. Miyoshi,
M. Ueda, K. Fuke, Y. Tanimoto, M. Itoh, and G. Tomita, Z. Naturforsch. 37b, 649 - 652(1982).
(17) "Electronic Absorption Spectra of Phenol Dimer and Toluene-Cyanobenzene
Complexes as Studied by Mass Selected MPI-Nozzle Method", K. Fuke and K. Kaya,Chem. Phys. Lett. 91, 311 - 314 (1982).
1

(18) "A Thermal Lensing Study of Singlet Oxygen Reaction", K. Fuke, M. Ueda, and M.
Itoh, J. Am. Chem. Soc. 105, 1091 - 1096 (1983).
(19) "Electronic Absorption Spectra of Phenol-(H 2 O) n and (Phenol) n as Studied by the MS
MPI Method", K. Fuke and K. Kaya, Chem. Phys. Lett. 94, 97 - 101 (1983).
(20) "Electronic Absorption Spectrum of Hg-Ar Complexes in a Supersonic Jet", K. Fuke, T.
Saito, and K. Kaya, J. Chem. Phys. 79, 2487 - 2488 (1983).
(21) Electronic Spectra of van der Waals Molecules HgNe, HgAr, and HgKr in a SupersonicJet", K. Fuke, T. Saito, and K. Kaya, J. Chem. Phys. 81, 2591 - 2598 (1984).
(22) "Multiphoton Ionization Photoelectron Spectroscopy and Two-color Multiphoton
Ionization Threshold Spectroscopy on the Hydrogen Bonded Phenol and 7-Azaindole ina Supersonic Jet", K. Fuke, Y. Yoshiuchi, K. Kaya, Y Achiba, K. Sato, and K. Kimura,Chem. Phys. Lett. 108, 179 - 184 (1984).
(23) "Electronic Spectra and Tautomerism of Hydrogen-bonded Complexes of 7-Azaindolein Supersonic Jet", K. Fuke, Y. Yoshiuchi, and K. Kaya, J. Phys. Chem. 88, 5840 5844 (1984).
(24) "Electronic Spectra and Predissociation of Methoxy and Methoxy-Ar Complex in the A
State", K. Fuke, K. Ozawa, and K. Kaya, Chem. Phys. Lett. 126, 119 - 123 (1986).
(25) "Double-Proton-Transfer Reaction in the Excited State of 1-Azacarbazole Dimer and1-Azacarbazole-7-Azaindole Heterodimer Studied in a Supersonic Jet", K. Fuke, T.
Yabe, N. Chiba, T. Kohida, and K. Kaya,, J. Phys. Chem. 90, 2309 - 2311 (1986).
(26) "Interatomic Potentials of HgXe van der Waals Complex Formed in Supersonic Jet as
Studied by Laser Induced Fluorescence Spectroscopy", K. Yamanouchi, J. Fukuyama,
H. Horiguchi, S. Tsuchiya, K. Fuke, T. Saito, and K. Kaya, J. Chem. Phys. 85, 1806 1811 (1986).
(27) "Electronic Spectrum of Hg(3P 0 )-Ar Complex in a Supersonic Jet", K. Fuke, S. Nonose,and K. Kaya, J. Chem. Phys. 85, 1696 - 1697 (1986).
(28) "Electronic Spectra and Intramultiplet Relaxation of Jet-Cooled Hg-CH 4 , C 2 H 6 , N 2 , andCO complexes", K. Fuke, T. Saito, S. Nonose, and K. Kaya, J. Chem. Phys. 86, 4745 4753 (1987).
(29) "Electronic Spectra and Electronic Relaxation in Mercury van der Waals Complexes
Studied in a Supersonic Jet" K. Kaya and K. Fuke, Physics and Chemistry of Small
Clusters, ed. by P. Jena, B. K. Rao, and S. N. Khana, Plenum Press, 1987, pp681 - 687.
(30) "Electronic Spectra and Molecular Structure of Biphenyl and Para-Substituted
Biphenyls in a Supersonic Jet", Y. Takei, T. Yamaguchi, Y. Osamura, K. Fuke, and K.
Kaya, J. Phys. Chem. 92, 577 - 581 (1988).
(31) "Electronic Spectra of Jet-Cooled Phenyl Nitrene", K. Ozawa, T. Ishida, K. Fuke, and K.
Kaya, Chem. Phys. Lett. 150, 249 - 253 (1988).
(32) "Reaction of Aluminum Clusters, Al n (n = 7-24), with Oxygen and Ammonia", K. Fuke,
Y. Sone, N. Kikuchi, and K. Kaya, Chem. Phys. Lett. 147, 479 - 483 (1988).
(33) "Photodissociation Dynamics of NH 3 : Rovibronic Absorption Analysis of the A-X
Transition and Nuclear Spin Polarization in the NH2 (X 2B1) Product", K. Fuke, H.
Yamada, Y. Yoshida, and K. Kaya, J. Chem. Phys. 88, 5238 - 5240 (1988).
(34) "Dynamics of Double-Proton-Transfer Reaction in the Excited-State Model Hydrogen
Bonded Base Pairs", K. Fuke and K. Kaya, J. Phys. Chem. 89, 614 - 621 (1989).
(35) "Reaction of Vanadium and Cobalt Clusters with Ethylene and Acetylene", S. Nonose,
Y. Sone, N. Kikuchi, K. Fuke, and K. Kaya, Chem. Phys. Lett. 158, 152- 156 (1989).
(36) “Reaction of Al n Clusters with Oxygen and Ammonia”, K. Kaya, K. Fuke, S. Nonose,and N. Kikuchi, Z. Phys. D12, 571 - 573 (1989).
2

(37) "The Intramultiplet Mixing of Zn(43P J ) by Collisions with 4He and 3He", H.Umemoto, A.
Masaki, T. Ohnuma, T. Takayanagi, S. Sato, F. Misaizu, and K. Fuke, J. Chem. Phys.
93, 4112 - 4116 (1990).
(38) "Photodissociation Dynamics of NH 3 , NH 2 D, NHD 2 , and ND 3 : Rovibronic Analysis of
the A-X Transition", A. Nakajima, K. Fuke, K. Tsukamoto, Y. Yoshida, and K. Kaya, J.
Phys. Chem. 95, 571 - 574 (1991).
(39) "The Intramultiplet Mixing of Zn(43P J ) by Collision with Ar", H. Umemoto, A. Masaki,
T. Ohnuma, F. Misaizu, and K. Fuke, J. Phys. B24, 1639 - 1644 (1991).
(40) "The Intramultiplet Relaxation of Cd(53P 2 ) by H 2 and D 2 ", H. Umemoto, A. Masaki, T.
Ohnuma, K. Kuwahara, Y. Wada, F. Misaizu, and K. Fuke, J. Chem. Phys. 94, 7951 7957 (1991).
(41) "Picosecond Measurements of the Vibrationally Resolved Proton-Transfer Rate of the
Jet-Cooled 1-Azacarbazole Dimer", K. Fuke, K. Tsukamoto, F. Misaizu, and K. Kaya, J.
Chem. Phys. 95, 4074 - 4080 (1991).
(42) "The Intramultiplet Relaxation of Cd(53P 2 ) Induced by Collisions with N2 and CO", A.
Masaki, T. Ohnuma, K. Kuwahara, H. Umemoto, Y. Wada, F. Misaizu, and K. Fuke,
Chem. Phys. 158, 155 - 160 (1991).
(43) "Photoionization of Clusters of Cs Atoms Solvated with H 2 O, NH 3 and CH 3 CN" F.
Misaizu, K. Tsukamoto, M. Sanekata, and K. Fuke, Chem. Phys. Lett. 188, 241- 246(1992).
(44) "Intersystem Crossing and Intramultiplet Mixing of Excited Zn Atoms by Xe", H.
Umemoto, T. Ohnuma, H. Ikeda, S. Tsunashima, K. Kuwahara, F. Misaizu, and K. Fuke,
J. Chem. Phys. 97, 3282 -3 288 (1992).
(45) "Photoionization of Solvated Cs Atoms", K. Fuke, F. Misaizu, K. Tsukamoto, and M.
Sanekata, Physics and Chemistry of Finite Systems: From Clusters to Crystals, ed by P.
Jena, S. N. Khanna, and B. K. Rao, NATO ASI Ser., Kluwer Academic Publishers,
Netherlands, 1992, p. 925-930.
(46) "Photodissociation of Size-Selected Mg+(H2O)n Ions for n =1 and 2", F. Misaizu, M.
Sanekata, K. Tsukamoto, and K. Fuke, and S. Iwata, J. Phys. Chem. 96, 8259 - 8264
(1992).
(47) "Electronic Structure and Reactivity of Mg+(H 2 O) n Cluster Ions", K. Fuke, F. Misaizu,
M. Sanekata, K. Tsukamoto, and S. Iwata, Z. Phys.D26, S180 -182 (1993).
(48) "Photoionization and Photodissociation Studies on Aluminum-Water Clusters and TheirIons", F. Misaizu, K. Tsukamoto, M. Sanekata, and K. Fuke, Z. Phys. D26, S177 - 179(1993).
(49) "Photoionization of Small Silicon Clusters: Ionization Potentials for Si 2 to Si 40 ", K.
Fuke, K. Tsukamoto, and F. Misaizu, Z.Phys. D26, S204 - S206 (1993).
(50) "Nascent Rotational State Distributions of ZnH(X2+) Produced in the Reaction ofZn(41P 1 ) with Simple Alkane Hydrocarbons", H. Umemoto, T. Sato, K. Takano, S.
Tsunashima, K. Kuwahara, K. Sato, H. Ikeda, F. Misaizu, and K. Fuke, Chem. Phys.
Lett., 214, 271-275 (1993).
(51) "Nascent Rotational and Vibrational Distributions in Both Products of the Reaction:
Zn(41P 1 ) + H 2 O —> ZnH(X 2∑+) + OH(X 2∏)", K. Kuwahara, H. Ikeda, H. Umemoto,T. Sato, K. Takano, S. Tsunashima, K. Sato, F. Misaizu, and K. Fuke, J. Chem. Phys.
99, 2715 - 2722 (1993).
(52) "Near Threshold Photoionization of Silicon Clusters in the 248-146 nm region:
Ionization Potentials of Si n " K. Fuke, K. Tsukamoto, M. Sanekata, and F. Misaizu, J.
Chem. Phys. 99, 7807 - 7811 (1993).
3

(53) "Photodissociation Study on Mg+(H 2 O) n , n=1-5: Electronic Structure and Photoinduced
Intracluster Reaction", F. Misaizu, M. Sanekata, and K. Fuke, J. Chem. Phys. 100, 1161 1170 (1994).
(54) "Photoionization of Hypervalent Molecular Clusters: Electronic Structure and Stabilityof NH 4 (NH 3 ) n ", K. Fuke, R. Takasu and F. Misaizu, Chem. Phys. Lett., 229, 597 - 603(1994).
(55) "Nascent Internal State Distributions of ZnH(X 2+) Produced in the Reaction of Zn(41P 1 )with Some Alkane Hydrocarbons", H. Umemoto, S. Tsunashima, H. Ikeda, K. Takano,
K. Kuwahara, K. Sato, K. Yokoyama, F. Misaizu, and K. Fuke, J. Chem. Phys. 101, 4803
- 4808 (1994).
(56) "Reaction of Singly Charged Alkaline-earth Metal Ions with Water Clusters:
Characteristic Size Distribution of Product Ions", M. Sanekata, F. Misaizu, K. Fuke, S.
Iwata, and K. Hashimoto, J. Am. Chem. Soc. 117, 747 - 754 (1995).
(57) "Photoelectron Spectroscopy of Mass-Selected Copper-Water Cluster Negative Ions", F.
Misaizu, K. Tsukamoto, M. Sanekata, and K. Fuke, Laser Chem. 15, 195 - 207 (1995).
(58) "Molecular Orbital Studies of the Structures and Reactions of Magnesium-water Cluster
Ions Mg+(H 2 O) n ", H. Watanabe, S. Iwata, H. Nakamura, K. Hashimoto, F. Misaizu, andK. Fuke, J. Am. Chem. Soc. 117, 755 - 763 (1995).
(59) “Ultrafast Photochemistry of Ammonia Clusters: Formation and Decay of Hypervalent
Molecular Clusters Containing the NH 4 Radical”, K. Fuke and R. Takasu, Bull. Chem.
Soc. Jpn., 68, 3309 - 3318 (1995).
(60) "Photodissociation Study on Ca+(H 2 O) n , n = 1-5: Electronic Structure and Photoinduced
Intracluster Reaction", M. Sanekata, F. Misaizu, and K. Fuke, J. Chem. Phys. 104, 9768
- 9778 (1996).
(61) "Electronic Structure and Stability of NH 4 (NH 3 ) n and NH 4 (NH 3 ) m (H 2 O) n ", R. Takasu,
K. Fuke, and F. Misaizu, Surface Review and Letters, 3, 353 - 357 (1996).
(62) "Photoelectron Spectroscopy of Mass-Selected Metal-Water Cluster Negative Ions" , F.
Misaizu, K. Tsukamoto, M. Sanekata, and K. Fuke, Surface Review and Letters, 3, 405 –
410 (1996).
(63) “Study on Microscopic Solvation Process of Li Atom in Ammonia Clusters:
Photoionization and Photoelectron Spectroscopies of M(NH 3 ) n (M=Li, Li-)”, R. Takasu,
K. Hashimoto, and K. Fuke, Chem. Phys. Lett., 258, 94 - 100 (1996).
(64) "Electronic structure and stability of hypervalent molecular clusters". K. Fuke and R.
Takasu, "Structures and Dynamics of Clusters" T. Kondow, K. Kaya and A. Terasaki,
Eds., Universal Academy Press Inc. Tokyo, Japan. pp.219 - 226 (1996).
(65) "Microscopic Solvation Process of Alkali Atoms in Finite Clusters: Photoelectron andPhotoionization Studies of M(NH 3 ) n and M(H 2 O) n (M=Li, Li-, Na-)", R. Takasu, F.
Misaizu, K. Hashimoto, and K. Fuke, J. Phys. Chem.101, 3078- 3087 (1997).
(66) ”Ab initio MO Study of Solvated Negative Alkali Atom Clusters: (M(H 2 O) n ）- and(M(NH 3 ) n ）- (M = Na and Li, n = 1-3-)”, K. Hashimoto, T. Kamimoto, and K. Fuke, Chem.
Phys. Lett., 266, 7 - 15 (1997).
(67) “Microscopic Solvation Process of Single Li Atom in Small Water", R. Takasu, T.
Taguchi, K. Hashimoto, and K. Fuke, Chem. Phys. Lett, 290, 481 - 487 (1998).
(68) "Solvation of Sodium Dimer in Ammonia Clusters; Photoelectron Spectroscopy and abinitio Study of Na 2 - (NH 3 ) n ", R. Takasu, K. Hashimoto, R. Okuda, and K. Fuke, J. Phys.
Chem. 103, 349 - 354 (1999).
(69) "Structures, Spectroscopies and Reactionsof Atomic Ions with Water Clusters", K.
Fuke, K Hashimoto, and S. Iwata, Adv. Chem. Phys. 110, 431 - 523 (1999).
4

(70) "Near Threshold Photoionization of Germanium Clusters in the 248-144 nm Region:
Ionization Potentials for Ge n ", K. Fuke and S. Yoshida, Europ. Phys. J. D., 9. 127 - 131(1999).
(71) “Electronic Spectra of Solvated NH 4 Radicals, NH 4 (NH 3 ) n (n = 1 - 6)”, S. Nonose, T.
Taguchi, K. Mizuma and K. Fuke, Europ. Phys. J. D., 9. 309-311 (1999).
(72) “Photoionization Studies of Germanium and Tin Clusters in the Energy Region of 5.0 8.8 eV: Ionization Potentials for Ge n (n = 2 - 57) and Sn n (n = 2 - 41)”, S. Yoshida and K.
Fuke, J. Chem. Phys. 111, 3880 - 3890 (1999).
(73) “Solvation Process of Na m in Small Ammonia Clusters: Photoelectron Spectroscopy of
Na m - (NH 3 ) n (m ≤ 3)”, R. Takasu, H. Ito, K. Nishikawa, K. Hashimoto, R. Okuda, and K.
Fuke, J. El. Sepctros. Relat. Phenom. 106, 127 - 140 (2000).
(74) " Photoionization and photodissociation studies of semiconductor clusters S. Yoshida
and K. Fuke, Trans. Mat. Res. Jpn, 25 995 - 998 (2000).
(75) "Photodissociation Spectroscopy of Li—H 2 O and Li—D 2 O Complexes", R. Takasu, K.
Nishikawa, N. Miura, K. Hashimoto, C. P. Schulz, I.V. Hertel, and K. Fuke, J. Phys.
Chem. A105, 6602 - 6608 (2001).
(76) “Photodissociation of Mg+(NH 3 ) Ion", S. Yoshida, N. Okai, and K. Fuke, Chem. Phys.
Lett. 347, 93 - 100 (2001).
(77) Y. Oshima, O. Kajimoto, and K. Fuke, "Isolated supermolecules", V. Balzani, ed.
"Electron Transfer in Chemistry, Vol.4 Catalysis of electron transfer, Heterogeneous andgas-phase systems" Worley-VCH, 775 - 804 (2001).
(78) "Electronic Spectra and Structures of Solvated NH 4 Radicals, NH 4 (NH 3 ) n (n = 1 - 8)",
S. Nonose , T. Taguchi, F. Chen, S. Iwata, and K. Fuke, J. Phys. Chem., A 106, 5242 5248 (2002).
(79) "Photo-Induced Reactions of Hemin+(DMSO) n Clusters (n = 0 – 3) produced with
Electrospray Ionization", S. Nonose, H. Tanaka, No. Okai, T. Shibakusa, and K. Fuke,
Eur. Phys. J. D., 20, 619 - 626 (2002).
(80) " Photodissociation and Ab Initio Studies of Mg+(NH 3 ) n , n = 1 – 4: Electronic Structure
and Photoinduced Reaction", S. Yoshida, K. Daigoku, N. Okai, A. Takahata, A. Sabu, K.
Hashimoto and Kiyokazu Fuke, J. Chem. Phys. 117, 8657 - 8669 (2002).
(81) "Structure and Reactions of Biomolecular Ions Produced with Electrospray Ionization"
S. Nonose, H. Tanaka, N. Okai, T. Shibakusa, and K. Fuke, Eur. Phys. J. D., 24, 335 338 (2003).
(82) " Spectroscopy and Dynamics of NH 4 in Ammonia Clusters", Kiyokazu Fuke, in Trends
in Physical Chemistry, Vol. 10 (2004), pp25 - 48.
(83) "Ultrafast Relaxation Process of Excited-State NH 4 Radical in Ammonia Clusters", N.
Okai, A. Takahata,, M. Morita, S. Nonose, and K. Fuke, J. Phys. Chem. A108, 727 -733
(2004).
(84) “Electronic Structure, Stability, and Formation Dynamics of Hypervalent Molecular
Clusters: CH 3 NH 3 (CH 3 NH 2 ) n ", N. Okai, A. Takahata, and K. Fuke, Chem. Phys. Lett.
386, 442 - 447 (2004).
(85) "Multiphoton Ionization and Oxidation Processes of Mg-Ammonia Clusters", N. Okai, S.
Yoshida, K. Aranishi, A. Takahata and K. Fuke, Phys. Chem. Chem. Phys. 7, 921 - 929(2005).
(86) "Structures and Reactions of Hydrated Biomolecular Cluster Ions", S. Nonose, S.
Iwaoka, K. Mori, Y. Shibata, and K. Fuke, Europ. Phys. J. D.,34 315 - 319 (2005).
(87) "Microscopic Dissolution Process of Na 3 in Water Clusters ", A. Fujihara, C. Miyata,and K. Fuke, Chem. Phys. Lett. 411, 345 - 349 (2005).

5

(88) "Hydration Process of Alkaline-earth Metal Atoms in Water Clusters", N. Okai, H.
Ishikawa§ and K. Fuke, Chem. Phys. Lett. 415, 155-160 (2005).
(89) “Hydration Process of Na 2 in Small Water Clusters: Photoelectron Spectroscopy andTheoretical Study of Na 2 -(H 2 O) n ”, A. Fujihara, C. Miyata, A. Maekawa, and K. Fuke K.
Daigoku, N. Murata, and K. Hashimoto, J. Phys. Chem. A 111, 7364 - 7373 (2007).
(90) “Photodissociation and Spectroscopic Study of Cold Protonated Dipeptides”, A. Fujihara,
H. Matsumoto, Y. Shibata, H. Ishikawa, and K. Fuke, J. Phys. Chem. A , 112, 1457 1463 (2008).
(91) "Solvation Structure and Stability of Hypervalent NH 4 (CH 3 OH) m (NH 3 ) n Clusters", Y.
Yamada, Y. Nishino, A. Fujihara, H. Ishikawa, and K. Fuke, Chem. Phys. Lett. 459, 65 69 (2008).
(92) "Real-time Observation of Formation and Relaxation Dynamics of NH 4 in
(CH 3 OH) m (NH 3 ) n Clusters", Y. Yamada, A. Fujihara, Y. Nishino, H. Ishikawa, K. Fuke,
J. Phys. Chem. A 113, 2734 - 2744 (2009).
(93) “Microsolvation and Protonation Effects on Geometric and Electronic Structures of
Tryptophan and Dipeptides”, A. Fujihara, N. Noguchi, Y. Yamada, H. Ishikawa, and K.
Fuke, J. Phys. Chem. A 113, 8169 – 8175 (2009).
(94) “Infrared Spectroscopy of Jet-Cooled Tautomeric Dimer of 7-Azaindole: A Model
System for the Ground-State Double Proton Transfer Reaction” H. Ishikawa, H.
Yabuguchi, Y. Yamada, A. Fujihara and K. Fuke, J. Phys. Chem. A114, 3199-3206(2010).
(95) "Development of Novel Spectroscopic Magnet Combining Mass Spectroscopy with
Nuclear Magnetic Resonance" K. Kominato, M. Takeda, I. Minami, R. Hirose, O. Ozaki,
H. Ohta, H. Tou, H. Ishikawa, M. Sakurai, and K. Fuke, IEEE Transactions on Applied
Superconductivity,20,736- 739 (2010).
(96) "Solvation Structure and Stability of ((CH 3 ) 2 NH) m (NH 3 ) n -H Hypervalent Clusters:
Ionization Potentials and Switching of Hydrogen-atom Localized Site", Y. Yamada, H.
Ishikawa, and K. Fuke, J. Phys. Chem. A115, 8380-8391 (2011).
(97) "Photodissociation spectroscopy of the temperature controlled hydrated calcium ion" H.
Ishikawa, T. Nakano, T. Eguchi, T. Shibukawa, and K. Fuke, Chem. Phys. Lett. 514, 234238 (2011).
(98) "Design and development of a novel nuclear magnetic resonance detection for the gas
phase ions by magnetic resonance acceleration technique" , K. Fuke, M. Tona, A.
Fujihara, and H. Ishikawa, Rev. Sci. Instrum. 83, 085106-1-8 (2012).
(99) “Deuteration effect on the NH/ND stretch band of the jet-cooled 7-azaindole and its
tautomeric dimers: Relation between the vibrational relaxation and the ground-state ”, H.
Ishikawa, T. Nakano, T. Takashima, H. Yabuguchi, and K. Fuke, Chem. Phys. 419, 101106 (2013).
(100) “Dynamics of Proton Transfer Reactions of Model Base Pairs in the Ground andExcited States: Revisited”, K. Fuke, and H. Ishikawa, Chem. Phys. Lett. 623, 117-129(2015) (Invited).
(101) “Preparation of cold ions in strong magnetic field and its application to gas-phase
NMR spectroscopy “, K. Fuke, Y. Ohshima, and M. Tona, Hyperfine Interactions,236(1), 9-18 (2015).

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Reviews(1) K. Fuke, "Application of Thermal Lens Effect on Molecular Spectroscopy", Journal of theSpectroscopical Society of Japan, 29, 333 (1980).
(2) K. Fuke and K. Kaya, "Preparation of gas-phase clusters with molecular beam", Kagaku,52, 648(1982).
(3) K. Fuke, A. Nakajima, and K. Kaya, “Dynamics of double proton transfer reaction in the

excited state of hydrogen bonded dimers as studied in a supersonic jet.” Dynamics andMechanisms of Photoinduced Transfer and Related Phenomena. (N. Mataga, T.
Okada,and H. Masuhara, eds.) (Amsterdam, Elsevier Science Publishers B.V., 1992).
Pages 167-173.
(4) K. Fuke, "Physical and Chemical Proprties of Gas phase Silicon Clusters", Hyomen
Kagaku, 14, 222-228 (1993).
(5) K. Fuke, " Spectroscopy and Dynamics of NH 4 in Ammonia Clusters", in Trends inPhysical Chemistry, Vol. 10 (2004), Pages 25-48.
(6) A. Fujihara, H. Ishikawa, K. Fuke , "Construction of a Temperature-Variable
Photodissociation Spectrometer for Gas-Phase Cluster Ions and Its Application to
Peptides" The Bulletin of the Nano Science and Technology, 6, 29-34, 2007.
Book(1) K. Fuke, K. Hashimoto, and R. Takasu, "Solvation of Sodium Atom and Aggregates inammonia Clusters", in Advances in Metal and Semiconductor Clusters Vol. 5, Ed. by M.
M. Duncan, pages 1-38, Elsevier, 2001.

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