b
c
C H O F Se Ta
Ta(V)-F bond lengths (Å) Ta1-F(1) 1.892(3)
Ta1- F(2) 1.892(3) Ta1-F(3) 1.895(3)
H6B H6C
C6
H6A
SE2 C4 H5A
H5C C3
H10B C5
SE4 C1 C2 SE1
C10 C8 H10A
H5B SE3
C7 H9C
H10C C9 O1
H9A H9B RE1 O2
a c
C H O Re Se b
c
C H F Se Re Cl
Electrocrystallization set up
[1]Electrode :
Pt wire Ø =1 mm
Electrolyte (A-)
Electron donor (D)
Monocrystals
D D
+• D
+•, D
0, A
-Cation radical salt = Material Oxydation :
Attempts to synthesize the (TMTTF)2Re(V)F6 salt : do not work, TMTTF is immediatly oxydized by Re(V)
TETRAMETHYL- TETRASELENAFULVALENE
D = TMTSeF
1) Solvent : CH3CN/1.1.2 TCE 11/1 mL T = 3°C, I = 1 to 5 µA2
PHASES IN THE SAME CELLUnit cell, T = 150 K, = 0.71073 Å : a = 7.9969(7)Å alpha = 77.707(9)° b = 11.072(1)Å beta = 75.377(7)° c = 13.171(1)Å gamma = 73.42(1)° V = 1068.9(2) Å3
R1 = 3.70%
Triclinic system, P-1
(TMTSeF)2Re(V)F6 : rhénium (IV) has been oxydized in rhénium (V) (TMTSeF)3Re(IV)F4Cl2
Unit cell, T = 150 K, = 0.71073 Å a = 7.1590(8)Å alpha = 83.28(1)° b = 7.741(1)Å beta = 87.15(1)°
c = 13.706(3)Å gamma = 70.19(1)° V = 709.7(2) Å3
R1 = 2.63%
Triclinic, P-1
b c
C H F Se Re
« Bechgaard » phase [3]
Very small needles!
RADICAL CATION SALTS OF TTF DONORS WITH XF
6(X = Re, Ta) ANIONS
Cécile Mézière
1, Magali Allain
1, Flavia Pop
1, Kasper Pedersen
2, Rodolphe Clérac
2, Pascale Auban Senzier
3, Jesper Bendix
4, Narcis Avarvari
11Laboratoire MOLTECH-Anjou, UMR6200 CNRS-Université d’Angers, Faculté des Sciences, Bât. K, 2 Bd Lavoisier, 49045 Angers Cedex, France
2Centre de Recherche Paul Pascal, UPR CNRS 8641, Equipe "Matériaux Moléculaires & Magnétism" (M3), 115 avenue du Dr. A. Schweitzer, 33600 Pessac, France
3Laboratoire de Physique des Solides, UMR8502 CNRS-Université Paris Sud, Bât. 510, 1 rue Nicolas Appert, 91405 Orsay Cedex, France
4Department of chemistry, Bât. B208, University park 5, 2100 Copenhague, Danemark
Strong dimerization → insulating 1D system
(TMTTF)
2Re
(IV)F
6A = (Ph
3-PNP-Ph
3)
2Re
(IV)F
6(H
2O)
xSolvent : CH3CN/1.1.2 TCE 11/1 mL T = 3°C, I = 1 to 5 µA
D = TMTF
[2]Unit cell, RT, = 1.540598 : a = 7.9941(17)Å α = 79.85(2)° b = 8.121(2)Å β = 89.145(18)° c = 11.372(3)Å γ = 65.466(18)° V = 659.71(30) Å3
Triclinic system, P-1
A = (Ph
3-PNP-Ph
3)
2Re
(IV)F
6(H
2O)
xTETRAMETHYL- TETRATHIAFULVALENE
+
Prisms
Re(V)-F bond lengths (Å) Re1-F(1A) 1.875(3)
Re1-F(1B) 1.88(2) Re1-F(2A) 1.889(3) Re1-F(2B) 1.796(18) Re1-F(3) 1.870(3) Re(IV)-Hal bond lengths (Å) :
Re1-F(1) 1.953(3) Re1-F(3) 1.951(3) Re1-Cl(1) 2.3183(2)
F3 Re1
F1B F2B
F1A H9C
H7B
F2A
C9
Se3 Se1 C7
H9A
H9B
H7A
H7C
C5 C3
C2 C1
C6 C4
H10A
H10C
H8C C10
H8A
Se4 Se2
H10B C8
H8B
2) Solvent : CH3CN/1.1.2 TCE 11/1
T = 20°C, I = 0.5 µA Only the (TMTSeF)2Re(V)F6 phase
Unit cell at 100K : the disorder on F atoms disappears Magnetism (R. Clérac) : measurements in progress
Resistivity (P. Auban Senzier)
A = (Ph
4)Re
(V)F
6Uniform stacking of oxydized TMTSeF molecules, isolated chains
Larger needles
A = TBATa
(V)F
6 Diamagnetism/probe
Unit cell, T = 100K, = 1.54184 Å a = 7.1344(4)Å α = 83.378(5)°
b = 7.7255(5)Å β = 87.118(5)° c = 13.7204(9)Å γ= 70.200(6)° V = 706.72(8) Å3
Z=1, R1 = 3.17%
Triclinic system, P-1
a
c
C H F Se Ta
TaF5 + TBABF4 → TBATaF6 [4 ] (TMTSeF)2TaF6
[1] P. Batail, K. Boubekeur, M. Fourmigué, J.-C. Gabriel, Chem. Mater., 1998, 10, 3005-3015
[2] J.M. Fabre, L. Giral, A. Gouasmia, H.J. Cristau, Y. Ribeill, Bull. Soc. Chim. Fr, 1987, N°5, 823-826
[3] K. Bechgaard, C.S. Jacobsen, K. Mortensen, H.J. Pedersen, N. Thorup, Solid State Commun. 1980, 33, 1119-1125.
[4] S. Brownstein, Inorg. Chem., 1973, 12, 584-589.
[5] S. Perruchas, J. Fraxedas, E. Canadell, P. Auban-Senzier P. Batail, E. Canadell, Adv. Mater. 2005, 17, 209-212
New (TMTSeF)2ReO4 phase = « Bechgaard » phase polymorph
Focus : pre_oxydation of the Re
(IV)salt in situ
(Ph3-PNP-Ph3)2 Re(IV)F6(H2O)x salt: 2 éq. mol Solvent : CH3CN/1.1.2 TCE 11/1
T = 20°C, I = 10 µA during 5 days in order to oxydize 50% of the anion
Then the TMTSeF is added in the anodic compartment and I = 2 µA
Unit cell, T = 150K, = 1.54184 Å a = 11.7777(3)Å
b = 8.7928(2)Å β = 95.461(2)° c = 27.0167(6)Å
V = 2785.12(11) Å3 Z=4, R1 = 2.52%
Monoclinic system, C 2/c Like (TMTSeF)2ClO4 called « µ »phase [5]
Shiny platelets : too small for
physics!
Ref Synth. Met. 1991, 42, 1939-1942
Unit cell, T = 150K, = 0.71073 Å a = 7.7344(7)Å α = 92.376(5)°
b = 10.8408(8)Å β = 98.270(6)° c = 13.6409(9)Å γ = 103.103(7)° V = 1099.13(15) Å3
Z=1, R1 = 4.39%
Triclinic system, P-1
TaF5 + HF → HTaF6 TBAHSO4 TBATaF6? (TMTSeF)3Ta2OF10 TBA2Ta2OF10
D0
« Bechgaard » phase [3]
