Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Do -Dimers of Tetrathiafulvalene Cation Radicals Really Exist at Room
Temperature?
V. Khodorkovsky, L. Shapiro, P. Krief, A. Shames, M. Giffard, A. Gorgues, G.
Mabon
1. Electronic absorption spectra:
Spectra were recorded on Hitachi U-1100 (200 – 1100 nm) and JASCO V-570 (190 – 2500
nm).
4.0
Norm. Absorbance (a.u.)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
400
600
800
1000
1200
Wavelength (nm)
Figure 1. Electronic absorption spectra (normalized on the longest wavelength maxima).
Solid line: TTF+. CF3SO3- max(264) = 1500, max(338) = 5400, max(436) = 15200, max(580)
= 4200; dashed line: TMTTF+. CF3SO3- max(274) = 1500, max(342) = 4500, max(460) =
16700, max(525) = 3700, max(652) = 7400 (acetonitrile, room temperature).
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Norm. Absorbance (a.u.)
2.0
1.5
1.0
0.5
0.0
400
600
800
1000
1200
1400
1600
1800
2000
Wavelength (nm)
Figure 2. Electronic absorption spectra (normalized on the longest wavelength maxima).
Solid line: TMT-TTF+. CF3SO3- max(260) = 17000, max(456) = 11700, max(843) = 9700;
dashed line: ET+. CF3SO3- max(346) = 5700, max(456) = 9500, max(478) = 9100, max(570) =
2100, max(954) = 10500 ) (acetonitrile, room temperature).
1.4
Norm. Absorbance (a.u.)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
400
500
600
700
800
900
1000
1100
Wavelength (nm)
Figure 3. Normalized absorption spectra of TMT-TTF+. CF3SO3-. Solid line: C  2*10-3 M;
dashed line: C  1*10-5 M (acetonitrile, room temperature).
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
Norm. Absorbance (a.u.)
1.0
0.8
0.6
0.4
0.2
0.0
400
500
600
700
800
900
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1100
Wavelength (nm)
Figure 4. Normalized absorption spectra of ET+. CF3SO3-. Solid line: C  10-3 M; dashed
line: C  10-4 M; short dashed line: C  10-5 M (acetonitrile, room temperature).
1
2.0
Absorbance (a.u.)
1.6
3
1
1.2
1
3
3
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0.4
0.0
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600
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1200
Wavelength (nm)
Figure 5. Vis/NIR spectra of TMT-TTF.+ (5x10-4 M) in acetonitrile at –10oC (1), 20oC (2)
and 60oC (3).
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
2. EPR spectra and simulation:
EPR spectra of ethanol solutions of TTF derived cation radicals were recorded using Bruker
EMX-220 digital X-band (9.4 GHz) spectrometer equipped with Bruker ER 4121VT
temperature controller within the temperature range 190 (0.1) K  T  320 (0.1) K.
Solutions were placed into sealed 1-mm i.d. glass capillary tubes which are EPR silent within
the region of interest. All spectra were recorded at non-saturating microwave power of 200
W and 100 kHz magnetic field modulation of 0.02 mT and 0.005 mT. Precise determination
of g-factors and concentrations were done by simultaneous recording of the sample under
study and ethanol TEMPOL solutions (g = 2.0059  0.0001) of the concentration
corresponding to the signal strength (1.110-3 M or 310-5 M). g-factors were determined
from the minima in the 2nd derivative of EPR spectra. Spectra processing (digital filtering,
differentiation, numerical integration, etc.) was done using Bruker WIN-EPR Software.
Spectra simulation was done by Bruker SimFonia and NIEHS P.E.S.T. Winsim Simulation
Software.
EPR Spectra Simulation
Primary simulation of compounds containing low natural abundance isotopes (like 33S which
is only 0.76%) was done using SimFonia Software. Then, after getting the correct number of
interacting nuclei, final simulation and spectral parameters’ optimization was done using
Winsim Software.
TTF+.
Hyperfine Coupling Parameters Found :
4 equivalent protons ( I = 1/2) with a(1H) = 0.123  0.005 mT
4 equivalent sulfurs ( I = 3/2) with a(33S ) = 0.414  0.005 mT
Carbon hyperfine coupling parameter could not be determined since no resolved satellite
hyperfine lines from 13C (natural abundance 1.1%) were detected. Since these signals are
overlapped with the strong central line, the carbon coupling hyperfine parameter may be
estimated as a(13C) < 0.2 mT.
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
a)
EPR Signal Intensity (a.u.)
2
Experimental
1
Simulation
0
-1
327
328
329
330
331
332
Magnetic Field (mT)
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EPR Signal Intensity (a.u.)
b)
Experimental
0.0
Simulation
-0.2
328.5
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330.5
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Magnetic Field (mT)
Figure 6. EPR spectra of TTF +.solution in ethanol at T = 300 K,  = 9.268 GHz. Solid lines:
experimental spectrum; short dotted lines: of simulation and optimization. a) general view; b)
zoomed view of low and high-field regions with 33S hyperfine satellite lines.
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
TMT-TTF+.
Hyperfine Coupling Parameters found:
12 equivalent protons (I = 1/2) from methyl groups with a(1H) = 0.024  0.005 mT
4 equivalent sulfurs (I = 3/2) with a(33S ) = 0.380  0.005 mT
Only 4 equivalent sulfur atoms (but not 8) provide the best fit for the intensities of both
central and satellite sulfur lines (Figure 8 a and b). It is reasonable to suppose another 4
sulfurs are far from the maximum of the unpaired electron density and the hyperfine coupling
parameter is too small for providing resolved lines outside the strong central line. Carbon
hyperfine coupling parameters could not be determined since no resolved satellite hyperfine
lines from both central and methyl 13C (natural abundance 1.1%) were detected. Since these
signals are overlapped with the strong central line, the carbon coupling hyperfine parameter
may be just estimated as a1(13C) < 0.2 mT for two central carbons and a2(13C) ~ 0.01 mT for
methyl carbons.
2.0
a)
EPR Signal Intensity (a.u.)
1.5
1.0
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-1.0
327
328
329
330
Magnetic Field (mT)
331
332
Supplementary Material (ESI) for Chemical Communications
This journal is © The Royal Society of Chemistry 2001
0.2
EPR Signal Intensity (a.u.)
b)
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Experimental
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Simulation
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-0.2
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Magnetic Field (mT)
EPR Signal Intensity (a.u.)
c)
2
0
-2
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Magnetic Field (mT)
Figure 7. EPR spectra of TMT-TTF +. solution in ethanol at T = 300 K,  = 9.263 GHz. Solid
lines: experimental spectrum, short dotted lines: simulation and optimization. a) general
view; b) zoomed view of low and high-field regions with 33S hyperfine satellite lines; c) 2nd
derivative EPR spectrum of the central line demonstrating proton hyperfine splitting.