スピンクロスオーバー現象とその光・スピン・電荷...
Transcript of スピンクロスオーバー現象とその光・スピン・電荷...
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スピンクロスオーバー現象とその光・スピン・電荷
による相乗効果
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Outline
(1) History of spin crossover phenomena
(2) Light induced excited state trapping (LIESST) and its related
phenomena
(3) Spin crossover transition at r.t. toward molecular devices
(4) Development of spin crossover complex film
(5) Development of assembled-metal complex exhibiting
dynamical spin equilibrium
(6) Development of mixed-valence complex exhibiting charge
transfer phase transition
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Molecular structure of Fe(S2CNR2)3(R = n-CnH2n+1, etc.). Temperature dependence of inverse magnetic
susceptibility for Fe(S2CNR2)3 (R = n-CnH2n+1).
L. Cambi, L. Szegö, Ber. Deutsch. Chem. Ges. 1933, 66, 656 (1933).
L. Cambi and A. Cagnasso, Atti Accad. Naz. Lincei. 1931, 13, 809
First report of spin-crossover phenomenon
HS(S = 5/2)
LS(S = 1/2) Fe(III):3d5
K. Stahl, i. Ymén, Acta Chem. Scand.,
A 1983, 37, 729
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Spin configuration of d4 – d7: It is possible that the low-spin (LS) state and the high-spin (HS) state compete with each other in the ground state.
d6d5 d7d4
P. Charpin, et al., J. Cryst.
Spectrosc. Res., 1988, 18, 429.
[Cr(II)I2(depe)2]
D.M. Halepoto, et al., J. Chem. Soc.,
Chem. Commun., 1989, 1322.
many Fe(III)
complexes
many Fe(II)
complexes
[Co(II)(H2fsa2en)(py)2]
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(1)P. L. Franke, et al. Inorganica Chimica Acta, 1982, 59, 5, (2) S. Decurtins et al. Chem. Phys. Lett. 1984, 105, 1.
S = 0 S = 2
T, P, hν
LIESST
S = 0 :low-spin state
S = 2 : High-spin state
[FeII(ptz)6](BF4)2
Light Induced Excited Spin State Trapping (LIESST)
N
NN
NPr
Ptz =
eg
t2g
Wave number (cm−1)
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Near-infrared and visible absorption spectra of [Fe(ptz)6](BF4)2 at 10 K: (―) before
light irradiation, (– – –) after irradiation with λ = 514.5 nm (300 mJ), (……) after
subsequent irradiation with λ = 752.7 nm (≈3000 mJ).
A. Hauser, Chem. Phys. Lett. 1986, 124, 543
LIESST (Light Induced Excited Spin State Trapping)
Colorless (HS state)
Purple (LS state)
Writing
Delete
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Mechanism of LIESST and Reverse-LIESST
Tanabe-Sugano diagram Mechanism of LIESST and Reverse-LIESST
A. Hauser, Chem. Phys. Lett. 1986, 124, 543Y. Tanabe, S. Sugano, J. Phys. Soc. Jpn.1954, 9, 766.
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Upper limit of LIESST
Figure 1. 7. Spin-crossover transition temperature vs
LIESST temperature. The lines represent the
correlation between the spin-crossover transition and
LIESST temperatures; T(LIESST) = T0-0.3T1/2.
J. F. Létard et al., Chem. Phys. Lett. 1999, 313, 115. .
ΔH T(LIESST)T1/2
ΔE
ΔE
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Spin crossover transition of [FeII(R-trz)3]A2·nH2O
N N
N
R
1,2,4-R-triazole
R = H, NH2, CnH2n+1,etc
memory, display device
cMT vs. T for [Fe(H-trz)2.85(NH2-trz)0.15](ClO4)2
cooling
heating
J. Kröber, E. Codjovi, O. Kahn, F. Grolière, C. Jay: J. Am. Chem. Soc. 1993, 115, 9810.
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Spin-transition polymers: From molecular materials toward memory devices
O. Kahn, C. Jay Martinez, Science, 1998, 279, 44.
Spin crossover transition of
[FeII(NH2trz)3](NO3)1.7(BF4)0.3
Principles of a display using a spin-
transition polymer.
bistability
http://www.sciencemag.org/content/279/5347/44/F7.large.jpghttp://www.sciencemag.org/content/279/5347/44/F7.large.jpghttp://www.sciencemag.org/content/279/5347/44/F6.large.jpghttp://www.sciencemag.org/content/279/5347/44/F6.large.jpg
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T = 300 K T = 77 K
[FeII(Htrz)3]-Nafion®
T1/2 = 260 K
Nafion®
SO3-
[FeII(Htrz)3]
A. Nakamoto, N. Kojima, et al., Chem.
Lett. 2003, 32, 336.
Development of Spin-crossover complex film
A. Nakamoto, N. Kojima et al.,
Polyhedron, 2005, 24, 2909.
7
6
5
4
3
2
1
0
吸収強度
86420距離(Å)
FeII(NH2-trz)3-Nafionβ
γI∝cos(γ+β)
r (Ǻ)
Inte
nsity
Fe-K edge EXAFS
-[CF2-CF2]x-[CF-CF2]y-
O-[CF2-CF-O]z-CF2-CF2-SO3H
CF3Nafion 117
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023.0
)(exp
stnHS
2
25)(
expst
nHS
(a)
(b)
X.J. Liu, Y. Moritomo, N. Kojima, et al. Phys. Rev. B, 2013, 67, 012102-1
Photo-generated HS state of
Nafion-[Fe(Htrz)3] filmLife time of photo-generated HS state
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(a) weak excitation (b) strong excitation
○:LS ●:HS
Condensed phase of photo-generated high-spin state
X.J. Liu, Y. Moritomo, N. Kojima, et al. J. Phys. Soc. Jpn. 2003, 72, 1615.
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Preparation of pH-sensitive spin-crossover
complex film, [FeII(diAMsar)]-Nafion
H. Kamebuchi, N. Kojima et al., Chem. Lett. 2011, 40, 888.
Nafion 117
pH 4 pH 7 pH 10
Volume expansion due to the Coulomb
repulsion between Fe2+ and NH3+
Absence of the volume
expansion
High-spin state
(S = 2; 5T2)
Low-spin state
(S = 0; 1A1)
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Manipulating the spin state by applied voltage
Coulomb repulsion
Voltage: 20 V
Current: ca.15 mA (average)
Time: 60 min
H. Kamebuchi: XXIV ICCBC, June 6, 17:10-17:20
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Spin State of FeIIIO3S3
FeIII(ox)3 FeIII(dto)3
FeIII(mto)3
FeIII
Weak ligand field
HS (S = 5/2)
FeIII
Strong ligand field
LS (S = 1/2)
FeIII
Spin-Crossover?
O
O
O
O
S
O
O
O
S
S
O
O3
3
3
HS (S = 5/2) LS (S = 1/2)
t2g
eg
t2g
eg
t2g
eg
t2g
eg
hn
P, T
16
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Slow spin-equilibrium at FeIIIS3O3(τ> 10−7 s)
HS
HSLS
LS
Tris(monothio-b-diketonato)iron( III)
M. Cox, et al, J. Chem. Soc. Dalton trans, 1972, 1192.
300 K
80 K
K. R. Kunze, et al, Inorg. Chem, 1977, 16, 594.
Rapid spin-equilibrium at FeIIIS3O3(τ< 10−7 s)
Tris(monothiocarbamato)iron( III)
NS
O
C2H
5
C2H
5 3
FeIII
296 K
93 K
Mössbauer spectra of Fe(Et2mtc)3
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K. Kagesawa, N. Kojima, et al., Chem. Lett., 2010, 39, 872.
X-band ESR
-4 -3 -2 -1 0 1 2 3 4
0.96
0.98
1.00
Velocity [mm/s]
0.96
0.98
1.00
Rel
ativ
e T
ransm
issi
on
0.985
0.990
0.995
1.000
300 K
200 K
77 K
57Fe Mössbauer spectra
HS + LS
Rapid spin-equilibrium of FeIII in (C6H5)4P[ZnIIFeIII(mto)3]
100 200 300 400 500
Inte
nsi
ty [
a. u
.]
H [mT]
LS state (g ≈ 4.25)
HS state (g ≈ 2.05)
─ 300 K─ 77 K─ 10 K
Rapid spin equilibrium
(10-10 s < t < 10-7 s)
(τ ≈ 10-10 s)(τ ≈ 10-7 s)
HSLS
egt2g
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Spin state of (C6H5)4N[MnIIFeIII(mto)3](mto = C2O3S)
O
S
O
O S
O
S
O
O
O
S
O
O
O
O
O
O
O
O
S
FeIII MnII
Effect of rapid spin
equilibrium on the
magnetic interaction
between FeIII and MnII
Rapid spin equilibrium
HSLS
Concerted phenomenon between the rapid spin
equilibrium and the succeeding magnetic phase
transitions for (Ph)4N[MnIIFeIII(mto)3].
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Theoretical value
FeIII (HS), MnII (HS)→ cT = 8.75 [emu K mol-1]
FeIII (LS), MnII (HS)→ cT = 4.75 [emu K mol-1]Experimental value
cT = 6.90 [emu K mol-1] (@400K)→spin equilibrium at FeIIIO3S3
0
1
2
3
4
5
6
7
8
9
10
0 100 200 300 400
0
0.01
0.02
0.03
0.04
0.05
0.06
0 100 200 300 400
FeIII (HS), MnII (HS)
cT = 8.75 [emu K mol−1]
FeIII (LS), MnII (HS)
cT = 4.75 [emu K mol−1]
cT
[e
mu K
mol-
1]
T [K]
c[e
mu m
ol-
1]
T [K]
c[e
mu m
ol-
1]
T [K]
0.042
0.044
0.046
0.048
0.05
0.052
0 20 40 60 80
30 K
23 K
Two-dimensional Heisenberg-type
antiferromagnetic interaction
23 K
30 K
Magnetic properties of (C6H5)4P[MnIIFeIII(mto)3]
magnetic ordering ?
20
Temperature dependence of magnetic susceptibility
K. Kagesawa, Doctoral Thesis (Univ. Tokyo, 2011)
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-10 -8 -6 -4 -2 0 2 4 6 8 100.90
0.95
1.00
Velocity [mm s-1
]
0.96
0.98
1.00
0.90
0.95
1.00
Rel
ativ
e T
ran
smis
sio
n 0.85
0.90
0.95
1.00
0.80
0.85
0.90
0.95
1.00
57Fe Mössbauer spectra of (C6H5)4P[MnIIFeIII(mto)3]
30 K
24 K
23 K
22 K
4.2 K
0.95
0.96
0.97
0.98
0.99
1
0.9
0.92
0.94
0.96
0.98
1
0.8
0.85
0.9
0.95
1
-5 -4 -3 -2 -1 0 1 2 3 4 5
300 K
200 K
77 K
HSLS
Rapid spin equilibrium
-5 -4 -3 -2 -1 0 1 2 3 4 5
Velocity (mm/s) Velocity (mm/s)
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0.92
0.94
0.96
0.98
1
-10 -5 0 5 10
0.95
0.96
0.97
0.98
0.99
1
0.75
0.8
0.85
0.9
0.95
1
30 K
22 K
10 K
Velocity [mm/s]
Rel
ativ
e tr
ansm
issi
on
0 5 10 15 20 25 30 35 400
2
4
6
8
10
12
14
16
M
[cm
3 m
ol-1
G]
T [K]
57Fe Mössbauer spectra
ACχ
FCM
RM
ZFCM
Successive magnetic phase transitions in (C6H5)4P[MnIIFeIII(mto)3]
K. Kagesawa, Doctoral Thesis (Univ. Tokyo, 2011)
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Rapid Spin Equilibrium and Magnetic Ordering
23 K 30 K
Mn & Fe→ order
Mn & Fe→ disorder
Mn → orderFe → disorder
T
G
0
Multi-step magnetic phase transitions induced by rapid
spin equilibrium in (C6H5)4P[MnIIFeIII(mto)3]
MnII FeIII
30 K 23 K
Antiferro (inter layer) Antiferro (Mn-Fe)
K. Kagesawa, Doctoral Thesis (Univ. Tokyo, 2011)
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Crystal structure of (n-C3H7)4N[FeIIFeIII(dto)3]
FeII
FeIII
S
O
(n-C3H7)4N+
C18H28Fe2NO6S6Hexagonal P63 a = b = 10.0615(8) Å
c = 16.0424(7) Å
M. Itoi, M. Enomoto, N. Kojima, et al., Solid State Commn., 2004, 130, 415.
Honeycomb structure
a
b
0
c
Charge transfer phase transition in (n-C3H7)4N[FeIIFeIII(dto)3]
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57Fe Mössbauer spectra
Charge transfer phase transition in(n-C3H7)4N[FeIIFeIII(dto)3]
S
FeIII
S
S
S
S
S
O
FeII
O
O
O
O
O
S
FeII
SS
S
S
S
O
FeIII
OO
O
O
O
FeII (S = 2)FeIII (S = 1/2)
FeII (S = 0)
e-
e-
FeIII (S = 5/2)
120 K
N. Kojima, M. Seto, Yu. Maeda, et al., Solid State Commun. 2001, 120, 165.
High Temperature Phase (HTP)S = R ln(2×5)
Low Temperature Phase (LTP)S = R ln(1×6)
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Mӧssbauer spectra of (n-CnH2n+1)4N[FeIIFeIII(dto)3](n = 3 - 6)
n = 3,4: charge transfer phase transition (CTPT) n = 5,6: no CTPT
A: FeIII(S = 1/2)
B: FeII(S = 2)
C: FeII(S = 0)
D: FeIII(S = 5/2)N. Kojima, et al., Hyperfine Interactions, 2004, 156-157, 175.
LTP HTP
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FeII (S = 2)
FeIII (S = 1/2)
3.8 K
FeII (S = 0)
FeIII (S = 5/2)
4.2 K
FeII (S = 0) FeIII (S = 5/2) FeIII (S = 1/2) FeII (S = 2)
57Fe Mӧssbauer spectra in the ferromagnetic phase of
(n-CnH2n+1)4N[FeIIFeIII(dto)3](n = 3, 5)
n = 3 n = 5
-
●:fcm
■:rm
▲:zfcm
H = 30 G
n = 4n = 3
n = 5 n = 6
Ferromagnetism of (n-CnH2n+1)4N[FeIIFeIII(dto)3]
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(SP)[FeIIFeIII(dto)3]
Photochromic spiropyran (SP)
Cation
Iron mixed valence complex with
[FeIIFeIII(dto)3]−
∞ 2D- honeycomb layers
Anion SOO S
S
OO
S
S
OO
S
Fe3+
SO
O S
S
OO
S
S
OO
S
Fe3+
S
OO
S
SO
O S
S
OO
S
S
OO
S
Fe3+
SO
O S
S
OO
S
Fe2+
Fe2+
Fe2+
・Reversible photo-isomerization
・Long life time in solids
(several days in r.t.)
・Charge tarnsfer phase transition
・Ferromagnetic transition
UVN
ON+
I- I
Nd+
N
Od-
+-
Vis or D
N. Kida, N. Kojima, et al., J. Am. Chem. Soc., 2009, 131, 212.
Organic-inorganic hybrid system with photochromic cation
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Photo-isomerization of spiropyran in (SP)[FeIIFeIII(dto)3]
300 KUV (350 nm) irradiation After UV, Vis. (550 nm) irradiation
1.2
1.0
0.8
0.6
0.4
0.2
0.0800700600500400300
UV 60 minvis 10 minvis 30 min
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Ab
sorb
ance
800700600500400300
UV 60 minUV 30 minUV 20 minUV 10 minUV 0 min
N. Kida, N. Kojima, et al., J. Am. Chem. Soc., 2009, 131, 212.
Photoinduced effect on the ferromagnetism
T (K)T (K)
N
ON+
I-
I
Nd+
N
Od-
+-
UVVis or D
LTP HTP
Photo-isomerization of SP
-
1.00
0.95
0.90
0.85
0.801050-5-10
1.00
0.98
0.96
0.94
0.92
0.90
1050-5-10
6 K 6 K
HTP
HTP
LTPFeIII (S = 5/2)
FeIII (S = 1/2)
FeII (S = 0) FeIII (S = 1/2)FeII (S = 2)
FeII (S = 2)
UV
I
Nd+
N
Od-
+-
N
O
N+
I-
Closed form Open form
Velocity (mm/s)Velocity (mm/s)
N. Kida, N. Kojima, et al., Polyhedron, 2009, 28, 1694.
Tra
nsm
issi
on (
a.u.)
Tra
nsm
issi
on (
a.u.)
Expansion of the unit cell volume
due to the photo-isomerization of SP
Before UV irradiationAfter UV irradiation
UV
Disappearance of LTP under UV irradiation
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Schematic diagram of spin states transition by photo-irradiation
T / K75
HTP(A)
HTP(B)
LTP(A)
HTP(B)
B phase
A phase
B phase
hν hν
A phase Thermal charge transfer occurs
B phase No thermal charge transfer phase transition
black
deep purple
UVVis.
or D
KBr pellet
5 22
Ferromagnetic phase
charge transfer phase transition
TC shifts from 5 to 22 K by UV irradiation
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Photoinduced charge transfer phase transition at 70 K
Me N
O
N
Me N
O
N
Me N
O
N
Me N
O
N
SP type
Me N
δ+
NO
δ-
Me N
δ+
NO
δ-
Me N
δ+
NO
δ-
Me N
δ+
NO
δ-
e-
High TC (22 K) ferromagnetismLow TC (5 K) ferromagnetism
e- e- e-
hν1
hν2
LTP HTP
FeIII (S = 5/2)FeII (S = 0)
FeII (S = 2)
FeIII (S = 1/2)
MC type
N. KIda, et al., J. Am. Chem. Soc., 2009, 131, 212.
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Structure of rhodopsin
cis-trans photoisomerization of retinal
Photo-isomerization of retinal in visual cell
cone
rod
light
retinal
http://www.kiriya-chem.co.jp/q&a/q52.html
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Summary
(1)Development of transparent spin crossover complex film, [Fe(Htrz)3]-Nafion
and observation of LIESST
(2) Development of pH sensitive spin crossover complex film, [FeII(diAMsar)]-
Nafion and the direct observation of proton flow in Nafion
(3) Concerted phenomenon between the rapid spin equilibrium and the
successive magnetic phase transitions for (n-CnH2n+1)4N[MnIIFeIII(mto)3]
(mto = C2O3S)
(4) Charge transfer phase transition (CTPT) for iron mixed- valence complex,
(CnH2n+1)4N[FeIIFeIII(dto)3] (dto = C2O2S2)
(5) Concerted phenomenon between the photo-isomerization and charge
transfer phase transition in a photo-reactive organic-inorganic hybrid
complex, (SP)[FeIIFeIII(dto)3](SP = Spiropyran)