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ETHYLENEDIOXY SUBSTITUTED TTF'SETHYLENEDIOXY SUBSTITUTED TTF'SHideki Yamochi, Gunzi Saito

Kyoto University, JAPANyamochi@kuchem.kyoto-u.ac.jp

AcknowledgementProfessor F. Wudl and his group members (UCSB → UCLA)Professor J. Ulanski, Dr. J.K. Jestzka, Dr. A. Tracz (Lodz)Professor T. Nakamura and his group members (Hokkaido)Professor S. Koshihara and his group members (TIT)Dr. Y. Inayoshi and her group members (Aoyama)Professor K. Yakushi, Dr. O. Drozdova (IMS)Professors T. Ishiguro, K. Matsumoto, T. Goto

and their group members (Kyoto)In our group: Mr. T. Kikuchi, Dr. S. Horiuchi, Mr. T. Senga,

Dr. A. Otsuka, Dr. M. Maesato, Dr. K. Tsutsumi, Mr. S. Sekizaki, Mrs. C. Tada, Mr. T. Kawasaki, Mr. Y. Nagata, Mr. H. Sasaki, Mr. T. Aoki, Dr. Y. Yoshida, Mr. A. Ota, Mr. T. Haneda, Mr. M. Soeda

Since too many numbers of colleagues worked, the full list is not available here.

S

S

S

SO

O O

O

BEDO-TTF (BO)

S

SSS

SS

S

S

O

OSS

SS

O

O

Weight ⇓Size ⇓

⇒⇒

Phonon Freq. ⇑Band Width ⇓

⇒ Tc ⇑

Synthesis

O

O Cl

Cl+ N

S

S

O

O S

S NMe2

NMe2

S

S

refluxCH3CN

O

O

S

S NMe2 110°DMSO

Br2 0°CH2Cl2

O

O

S

SBr

NMe2

Br

O

O

S

SNMe2

Br 110°25 Torr

O

O

S

SSe H2Se

MeOH

(MeO)3Preflux in Bz

O

O

S

S

S

S

O

O

48 % 58 %

84 % 92 % 89 %

63 %T.Suzuki, H.Yamochi, G.Srdanov, K.Hinkelmann, F.Wudl, J.Am.Chem.Soc.,111, 3108(1989)

AimBirth of the First Etylenedioxy substituted TTF

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Initial Stage in Cation Radical Preparation of BO

H. Yamochi, et al., Synthetic Metals, 41-43, 1741 (1991)

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Initial Stage in Cation Radical Preparation of BO

H. Yamochi, et al., Synthetic Metals, 41-43, 1741 (1991)

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Superconductors based on BO

M.A. Beno, et al., Inorg. Chem. , 29, 1599 (1990)

βm-(BEDO-TTF)3Cu2(NCS)3

S. Kahlich, et al., Solid State Commun., 80, 191 (1991)

(BEDO-TTF)2ReO4(H2O)

Tc = 1.06 K (onset)R = 6.8%

Tc = 0.9 - 3.5 K (onset)R = 6.9%

•Unexpectedly Low Tc•Poor Quality of

Single Crystals

CT Complex with Organic Acceptor Molecules

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BO Complexes with Organic Acceptor Molecules

S. Horiuchi, et al., J. Am. Chem. Soc., 118, 8604 (1994).Horiuchi, et al., J. Am. Chem. Soc., 118, 8604 (1994).

BO afforded Metallic Complexes with the Acceptor Molecules having wide range of ∆E, Even in the form of Compressed Powder.

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BO Complexes: Why Organic Metals?

V vs. SCE. In 0.1 M Bu4NBF4/CH3CN

0.380.730.35TTF

0.260.660.40BEDO-TTF

0.230.740.51BEDT-TTF

∆EE21/2E1

1/2

Appropriate Redox Property.

(2) Appropriate Conducting Path.

NC

NC

CN

CN

NC CN

HCTMM2- =

(BEDO-TTF)5(HCTMM)(Ph-CN)2

Although the Crystal Structure Analyses were Difficult in General, …

(1) Partially Charge-Transferred Ground State.

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(BEDO-TTF)5(HCTMM)(Ph-CN)2Anion & Solvent: Severe Disorder→ No Specific Interactions

between BO and Anion Layer → Self-assembling Packing Pattern of BO

2D Layered Structure3a+c

vdWS•••S = 3.60 ÅS•••O = 3.32 Å

Side-by-sideHeteroatomic Contacts

a+2c

vdWH•••O = 2.72 Å

Weak Hydrogen Bond Network

→ 2D Electronic Structure

Calculated Fermi SurfaceI3-type Packing

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Donor Packing Patterns in Conducting BO Complexes

I3-type ( > 17 examples)

HCP-type (2 examples)

M(CN)4-type (2 examples)

DHCP-type (1 example)

Cl-type (1 example)

κ-type (1 example)

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Donor Packing Patterns in Conducting BO Complexes

I3-type ( > 17 examples)

HCP-type (2 examples)

M(CN)4-type (2 examples)

DHCP-type (1 example)

Cl-type (1 example)

κ-type (1 example)

Non-I3-type AnaloguesI3-type Packing is Partially Preserved

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Self-assembling Nature of BEDO-TTF (BO)

Although Specific Interatomic Interactions could Prohibit the Self-Assembly, in General,

I3-type ( > 17 examples)HCP-type (2 examples)M(CN)4-type (2 examples)DHCP-type (1 example)

Non-I3-typeCl-type (1 example)κ-type (1 example)

BO shows the Self-assembling Nature.Typically I3-type Packing (β"-type in BEDT-TTF).

How can we Apply this Novel Property?

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Application of the Self-assembling NatureMetallic Langmuir-Blodgett Films

Z

C10zTCNQzBOz

SS

SS

OO

OO

C C

C C

NN

N N

CH2

H2CCH2

H2CCH2

H2CCH2

H2CCH2

CH3

Metallic LB Film which requires no Secondary TreatmentMetallic down to ca. 250 K (50 K via Thermoelectric power)

←IRESR

T. Nakamura, et al., J. Phys. Chem., 98, 1882 (1994), K. Ikegami, et al., Synth. Met., 71, 1909 (1995)

σRT = 10 Scm-1

(BO)10(C10TCNQ)4(H2O) + C19H39COOH / Benzene → Horizontal Lifting / H2O

(BO)2[(MeO)2TCNQ]4 + C19H39COOH / Benzene → Horizontal Lifting / H2OσRT = 11.3 Scm-1 Metallic doun to 180 K (50 K via ESR)K. Ogasawara, et al., Jpn. J. Appl. Phys., 35, L571 (1996)

2(BO) + 1(C21H43COOH) / CHCl3 → Horizontal Lifting / H2OσRT = 40 Scm-1 Metallic doun to 14 KH. Ohnuki, et al., Phys. Rev. B, 55, R10255 (1997)

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Application of the Self-assembling NatureReticulate Doped Polymer (RDP) Films

·Swelling

I2 or Br2 /CH2Cl2, CHCl2-CH2Cl, or THF

5 mm

Surface Conducting Film1 × 103 Ω/• (≈ 10-3-10-2 Ωcm)

50 - 70 nm

Almost colorless film∼ 15 µm thicknessρ > 1012 Ωcm

BO (1 wt. %) + PC /Cl

ClCasted

at 120 °C

·Cast Film Formation

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Transparent Metallic RDP Film

S. Horiuchi, et al., Mol. Cryst. Liq. Cryst., 296, 365 (1997)

J.K. Jeszka, et al., Synthetic Metals, 106, 75 (1999)

Although Br2 Doped Films are Transparent, they are Metallic.

The Most Developed Face of the Crystallites // PC Film Surface

Long Axis of BO// Transition Moment of

Visible Absorption Band⊥ Crystallite Face

→ No Absorption of Light→ Conducting // Film Surface

Structural Model of Transparent Metallic Film.

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Recent Results on BO-Br Complex— Humidity Sensitive Electrical Resistance

(BO)2Br(H2O)3 Single Crystal

ca. 5 Torr ca. 10-2 TorrOpen to Air

Cyclic Changing of Resistance

Reversible Detaching of H2O

In Vacuum: High Resistance

In Ambient: Low Resistance

(BO)2Br(H2O)3 easily Looses Br2 under Vacuum.

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Recent Results on BO-Br Complex— Humidity Sensitive Electrical Resistance

(BO)2Br(H2O)3 Single Crystal

ca. 5 Torr ca. 10-2 TorrOpen to Air

Br2 Doped BO RDP Film

AtmosphereWater SaturatedDried over P2O5

Under Vacuum: Degradation by loosing Br2Wet & Dry Atmosphere: Cyclic Breathing of RDP Film

→ New Feature of Conducting CT Complexes

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Partial Suppression of Self-assembling Nature of BO

Self-assembling Arrangement of BO

= Tight PackingArea of Layer / Donor Molecule

BEDT-TTF: 25.0 - 28.5 Å2

BEDO-TTF: 20.4 - 21.8 Å2

Introduction of Bulky Substituent Removal of an

EDO Group

S

S

S

SO

O O

O

BEDO-DBTTF

S

S

S

SO

O S

S

EOET

S

S

S

SO

OEDO-TTF

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Introduction of Bulky Substituents to BO

S

S

S

SO

O O

O

S

S

S

SO

O S

S

Highly Conducting Complexes, but NO METALS

Rate of Metallic Complexes is Poorer than that of BO

T. Senga, et al., Mol. Cryst. Liq. Cryst., 296, 97(1997)G. Saito, et al., J. Mater. Chem., 12, 1640 (2002)

As a Cation Radical Salt, (EOET)2AuBr2 afforded Polymorphous and ….

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Antiferromagnet from EOET

Black Blocks (β"-phase)σRT = 60 Scm-1, Metallic down to 1.6 KBlack Needles (α'-phase)σRT = 5 ×10-3 Scm-1, Ea = 0.22 eV

T > 60 K: Quadratic Layer AF Model: |J|/kB = 90 – 100 K9 < T < 12 K: 3D AF Fluctuation

T. Aoki, et al., Mol. Cryst. Liq. Cryst., 376, 201-206 (2002)Y. Yoshida, et al., Mol. Cryst. Liq. Cryst., 394, 105 (2003)

T < 9 K: Long-range 3D AF Ordering: TN = 9 K

S

S

S

SO

O S

S

EOET

AuBr22

α'-type BEDT-TTF Complexes have not shown Long Range Order.

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O

O

S

SS +

CO2Me

CO2MeS

SO

P(OEt)3

O

O

S

S

S

S

CO2Me

CO2Me

O

O

S

S

S

S LiBr·H2O/HMPArt → 95°/14mmHg for 60 min95° → 150° under N2 for 30 min

65 %

52 % EDO-TTF

Removal of an EDO Group — EDO-TTF

T. Mori, et al, Chem. Lett., 1279 (1990)G. C. Papavassilliou, et al.,

Mol. Cryst. Liq. Cryst., 181, 171-184 (1990)M. Iyoda, et al., Heterocycles, 54, 833-848(2001)

A. Ota, et al., Mol. Cryst. Liq. Cryst., 376, 177-182 (2002)

Complexes with TCNQ derivatives

Complete Vanishing of Self-Assembling Nature

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EDO-TTF — Preparation of PF6 ComplexElectrooxidation (Electrocrystallization)EDO-TTF + (Bu4N)PF6/ EtOH → (EDO-TTF)2PF6

11.6 mg 68.1 mg 18 mL 0.5 µA black 12 days elongated plates

Triclinic P 1a = 7.197(0.9) Åb = 7.343(0.6)c = 11.948(1)α = 93.454(7)°β = 75.158(6)γ = 97.405(7)V = 605.0(1) Å3

Z = 1R = 5.6 %

Head-to-Tail Stacking along b-axis.Disordered Ethylene.Isotropic Rotation of PF6

-.

Almost Uniform 1D Intermolecular Overlap Integrals.

EDO-TTF was added to (+)side only, while ca. halfamount of (Bu4N)PF6 wasadded to each chamber.

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Physical Properties of (EDO-TTF)2PF6

At ≈ 280 K, the Complex showed Metal-to-Insulator Transition.

First Order Phase Transition

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(EDO-TTF)2PF6 — Above and Below TMI (280 K)

A. Ota, et al., J.Mater. Chem., 12, 2600 (2002)

plana

r: 0.8

º, 2.1

º

bent

: 11.1

º, 7.9

ºφ 1

, φ 2: 6

.0º , 0

.3º

Distinct Molecular Deformation

Overlap Integral

Uniform

Alternate

Peierls

from Bond

Length

0.5+

1+/0

Charge Ordering

PF6Rotation

Isotropic

Uniaxial

Order-Disorder

Flexibility and Adequate Size of EDO-TTF is regarded as the Origin to Mix Metal-Insulator Transition Mechanisms.

A. Ota, et al., J.Mater. Chem., 12, 2600 (2002)

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Concluding Remarks — Oxygen Substituted TTFs

BEDO-TTF: The First Member of this Family.Peculiar Feature of Self-AssemblingNew Morphologies of Organic MetalsMulti Functionality

H. Yamochi, "Oxygen Analogues of TTFs" in J. Yamda and T. Sugimoto ed. "TTF Chemistry" will be published in coming autumn.

The Next Generation of this Family Members are also providing New Functional Materials.

S

S

S

SO

O O

O

S

S

S

SO

O S

S

S

S

S

SO

O S

S O

OS