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1
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H21???????? (GL????)

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• ????( D1 ) ??????????????????????
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2
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20?? 21?? 22?? 23?? 24??
3
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?????????????? (photoelectrochemical cell)
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4
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5
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hn
T. Masuda, K. Shimazu and K. Uosaki, J. Phys.
Chem. C, 112, 10923-10930 (2008).
6
In situ XAFS Measurement During Electrochemical
Hydrogen Evolution
s-polarization
ion chamber
X-ray
sample
fluorescence
p-polarization
Pt L? edge (11.4-12.5 keV) was measured
SSD Solid State Detector
X-ray
sample
fluorescence
7
In situ XAFS Measurement During Electrochemical
Hydrogen Evolution
p-polarization
K2PtCl4(aq)
H2 adsorption
Before reduction
K. Asakura et al., J. Synchrotron Rad. 6, 1999,
439.
In situ, -0.75 V
Pt-Pt interaction
Pt foil
CN 7.20, R 2.73 Å
1.3 nm Pt Nanoparticle
k / Å
J. De Graaf et al., J. Cat. 203, 2001, 307
8
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9
Molecular Catalysts for Water Oxidation
Mn complexes
Ru complexes
NNN 2,26,2-terpyridine
J. Meyer et al. J. Am. Chem. Soc. 1982, 104,
4029 2008, 130, 16463
Limburg et al., Science 1999, 283, 1524.
R Mesityl
R CH3, OCH3, t-Bu etc.
Tanaka et al., Inorg. Chem. 2001, 40, 329.
Naruta et al., Angew. Chem. Int Ed. 2004, 43, 98.
Thummel et al., Inorg.Chem. 2008, 47, 1835.
10
??????
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?????
H2
???????????? ?????????????
hv
????? LUMO? ???M????
4,5d??
????? HOMO? ???M????
3d??
???????????? ??????????
1/2O2
11
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M2(bdt)44
M2(cat)44
Elucidation of Effect derived from Coordinating
Elements
Cr2(bdt)44
Mo2(bdt)44
W2(bdt)44
6???
Elucidation of Effect derived from Metal Species
12
MoIV(Bdt)32?????
Molecular Structure
d
e
b
a
c
f
S
Bond Lengths(Å) in MoS2C6H4 Moiety
a
b
c
e
f
d
Mo
A
1.746(3) 1.755(3)
1.394(5)
2.3930(7) 2.3995(10)
1.375(6) 1.372(5)
1.387(8)
1.398(4) 1.393(6)
B
1.751(3) 1.739(4)
1.404(5)
2.3975(11) 2.4002(8)
1.402(6) 1.379(7)
1.372(8)
1.398(6) 1.407(5)
C
1.748(5) 1.752(3)
1.396(5)
2.3800(11) 2.3982(11)
1.378(9) 1.385(6)
1.376(5)
1.394(6) 1.394(7)
Redox on the Ligand
Figure. Structure of Mo(bdt)32 in crystals.
Na ions, THF molecules and hydrogen atoms are
omitted for clarity.
S?????????????????????????????????????????????????
Benzenedithiolate (Bdt2)
Semiquinonate-type (S2SQ)
Benzoquinone-type (S2BQ0)
13
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1)?????? 2)????(?)?????? 3)??????????
E(Mo6/5) 0.61 V vs. NHE in THF E(Mo5/4)
-0.04 V
Cervilla et al., Inorg. Chem., 2005, 44, 4106.
14
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Pt2(pyt)2(L)2 ???????????
E(Pt2II,II/III,III) -1.5 V vs. NHE
15
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16
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n-

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