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Synthesis of novel Bis- and Tris-tetrathiafulvalene amphiphiles
S RTIHI TIII£ I I TALS Synthetic Metals 70 (1995) 1163-1164
ELSEVIER
Synthesis of Novel Bis- and Tris-Tetrathiafulvalene Amphiphiles. Roland P. parg,a Jeremy D. Kilburn,a* and Timothy G. Ryan c aDepartment of Chemistry, University of Southampton, Highfield, Southampton, SO17 1B J, UK b l c I Wilton Materials Research Centre, PO Box 90, Wilton, Middlesbrough, Cleveland, TS6 8JE, UK
Abstract Novel bis- and tris-tetrathiafulvalene (TTF) amphiphiles have been prepared by coupling together T I T monoamines or with TTF mono and diacids. This synthetic route provides a more efficient route to bis- and tris-TTF amphiphiles than that previously described.
In recent years Langmuir-Blodgett (LB) films of chargetransfer complexes have attracted considerable attention since this potentially allows the organisation of the electroactive moieties at the molecular level, and thus the possibility of producing thin films with useful conducting properties. 1 The synthesis of amphiphilic molecules containing tetrathiafulvalene (TIT) moieties for this purpose has received particular attention, because of the well-documented conducting and super-conducting properties of the chargetransfer salts of ~ derivatives.2 However, problems often encountered with LB films relate to their poor stability, both thermal and mechanical. In an effort to prepare TTFamphiphiles with enhanced LB film-forming properties, and hence LB films with greater stability, we have recently reported 3 the synthesis of a number of bis- and tris-TTF amphiphiles, such as 1.
S H3C
S
S ( H2)4NHCOCH2S
S
S
SCH2CONH(CH 2)4S
S CH3
have begun to vary the spacer unit between the individual TIT units, and varied the number of hydrophobic decylthio chains. Both these factors should influence the packing of the TTF units in the resulting thin films. In addition we have increased the number of amide groups in the amphiphiles which should allow greater inter- and intramolecular hydrogen bonding in the thin films, and thus greater ordering of the TTF's. The new bis- and tris-TTF amphiphiles were prepared by coupling of q"TF monoamines 6 and 7 with ~ diacid 12, or monoacids 8 or 10 (Scheme 1), using dicyclohexylcarbodiimide. The syntheses of the diacid 12 has already been described.3
The T I T monoamines 6 and 7 were prepared from
the diesters 2 and 3 by monode-carboxylation,4 hydrolysis of the monoesters (to give acids 8 and 10), coupling to monoprotected diaminopropane, and finally, removal of the trityl protecting group. The dimers and trimers were obtained analytically pure and have all been characterised by NMR and mass spectrometry. The syntheses outlined herein are shorter and more efficient than the syntheses of the earlier bis- and tris-TTF compounds, such as 2, 3 allowing access to a wide range of compounds with structural variations as outlined above. Studies on the film-forming properties of these new materials are now underway and will be reported in due course.
REFERENCES These materials did indeed have better film-forming properties, as compared to related mono-TTF amphiphiles, but conductivities of the resulting thin fims were low, before and after doping with iodine. In order to allow better control of the orientation of the TTF units we have now synthesised a range of new bis- and tris- TTF derivatives, 9, 11, 13 and 14, in which we 0379-6779/95/$09.50 © 1995 Elsevier Science S.A. All rights reserved SSD! 0379-6779(94)02802-6
1. See, for example, Ruaudel-Teixier, A.; Vandevyver, M.; Barraud, A. Mol. Cryst. Liq. Cryst. 1985, 120, 319; Nakamura, T.; Kawabata, Y. Techo. Jpn 1989, 22, 8; Vandevyver, M. Thin Solid Films 1992, 210-211, 240; Pearson, C.; Dhindsa, A. S.; Petty, M. C.; Bryce, M. ibid 1992, 210-211, 257 and references therein.
1164
R.P. Parg et al. / Synthetic Metals 70 (1995) 1163-1164
J, LiOH,dloxane,H20 S ~ s ii, H2N(CH2)3NHCPh3- ,-, y_ iii. 5%CF3CO2H,CH2CI2rtS'r ~5 •
refluxLiDMF., Br' ~ p . . ~ i O 2 M e Cl0H21 3 R, R = CH2CH2 2
R =
4
"
"
+
~r -H
6 R = CtoH21 7 R, R= CH2CH2
R = CloH21
5 FI,FI= CH2CH2
~ S~CONH(CH2)3NH3*s,,.. ~ , -~S ~ 7 b- ~H
~CONH(CH2)3NH3CF3C02"
a
S/'•S
CF3C02" DCC,HOBT, DIPEA,DMAP
H
8
CONH(CH2)3NHOC H 9
H2~CloS~ ~ ~
CONH(CH2)3NH3 ÷ CF3C02"
H21C1°S/~ 6 H H21C,OS~l~ . . ~ = S ~ C02H
H21Clo~SCloH21 H21CIo~SCloH21
DCC,HOBT. DIPEA,DMAP
H2,C,oS.,,.JLS/~-~'~L,. H
H
10
H21C1oS~1~ ~ . .
CONH(CHz)aNH3" CFaC02"
H21CloS'~ H 6 H21Clo~~s~,SCH2CO2H H21C|oS~
~
7 H21C,o S ~ ~ , . ~ . .
H2|C,o S ~ S / ~ ' = ~
SCH2CO2H
H2,CIo~SC,oH,,
H2,Cto~SC,oH2,
H/L~-~CONH(CH2)aNHOCCH2S/t'~SCH2CONH(CH2)3NHOC/~'=~H 13
CONH(CH2)3NH3*CFaC02 H
CONH(CH2)3NHOC H 11 27% H21C,oS~SC, oH2,
DCC,HOBT, DIPEA,DMAP
-- ~SCH2CO2H 12
~)~S~
21%
DCC.HOBT, DIPEA,DMAP
SCH2CO2H
~S
E "S
9%
H21Clo%~_.(SCloH21
S~ "S
~S
,~S
H~cONH(CH2)'NHOCCH2S~SCH2CONH(CH2)3NHOc-- H
12 14
13%
SCHEME 1
2 Williams, J. M.;Schultz, A. J.; Geiser, U.; Carlson, K. D.; Kini, A. M.; Wang, H. H.; Kwok, W. K.; Whangbo, M. H.; Schirber, J. E.; Science 1991, 252, 1502; Bryce, M. R. Chem. Soc. Rev. 1991, 20, 355.
3. Parg, R. P.; Kilburn, J. D.; Petty, M. C.; Pearson, C.; Ryan, T. G. Synthesis, 1994, 613. 4. Using a modification of the procedure reported by Duguay, G.; Gorgues, A. Synthetic Metals, 1993, 55-57, 2113.
ELSEVIER
Synthesis of Novel Bis- and Tris-Tetrathiafulvalene Amphiphiles. Roland P. parg,a Jeremy D. Kilburn,a* and Timothy G. Ryan c aDepartment of Chemistry, University of Southampton, Highfield, Southampton, SO17 1B J, UK b l c I Wilton Materials Research Centre, PO Box 90, Wilton, Middlesbrough, Cleveland, TS6 8JE, UK
Abstract Novel bis- and tris-tetrathiafulvalene (TTF) amphiphiles have been prepared by coupling together T I T monoamines or with TTF mono and diacids. This synthetic route provides a more efficient route to bis- and tris-TTF amphiphiles than that previously described.
In recent years Langmuir-Blodgett (LB) films of chargetransfer complexes have attracted considerable attention since this potentially allows the organisation of the electroactive moieties at the molecular level, and thus the possibility of producing thin films with useful conducting properties. 1 The synthesis of amphiphilic molecules containing tetrathiafulvalene (TIT) moieties for this purpose has received particular attention, because of the well-documented conducting and super-conducting properties of the chargetransfer salts of ~ derivatives.2 However, problems often encountered with LB films relate to their poor stability, both thermal and mechanical. In an effort to prepare TTFamphiphiles with enhanced LB film-forming properties, and hence LB films with greater stability, we have recently reported 3 the synthesis of a number of bis- and tris-TTF amphiphiles, such as 1.
S H3C
S
S ( H2)4NHCOCH2S
S
S
SCH2CONH(CH 2)4S
S CH3
have begun to vary the spacer unit between the individual TIT units, and varied the number of hydrophobic decylthio chains. Both these factors should influence the packing of the TTF units in the resulting thin films. In addition we have increased the number of amide groups in the amphiphiles which should allow greater inter- and intramolecular hydrogen bonding in the thin films, and thus greater ordering of the TTF's. The new bis- and tris-TTF amphiphiles were prepared by coupling of q"TF monoamines 6 and 7 with ~ diacid 12, or monoacids 8 or 10 (Scheme 1), using dicyclohexylcarbodiimide. The syntheses of the diacid 12 has already been described.3
The T I T monoamines 6 and 7 were prepared from
the diesters 2 and 3 by monode-carboxylation,4 hydrolysis of the monoesters (to give acids 8 and 10), coupling to monoprotected diaminopropane, and finally, removal of the trityl protecting group. The dimers and trimers were obtained analytically pure and have all been characterised by NMR and mass spectrometry. The syntheses outlined herein are shorter and more efficient than the syntheses of the earlier bis- and tris-TTF compounds, such as 2, 3 allowing access to a wide range of compounds with structural variations as outlined above. Studies on the film-forming properties of these new materials are now underway and will be reported in due course.
REFERENCES These materials did indeed have better film-forming properties, as compared to related mono-TTF amphiphiles, but conductivities of the resulting thin fims were low, before and after doping with iodine. In order to allow better control of the orientation of the TTF units we have now synthesised a range of new bis- and tris- TTF derivatives, 9, 11, 13 and 14, in which we 0379-6779/95/$09.50 © 1995 Elsevier Science S.A. All rights reserved SSD! 0379-6779(94)02802-6
1. See, for example, Ruaudel-Teixier, A.; Vandevyver, M.; Barraud, A. Mol. Cryst. Liq. Cryst. 1985, 120, 319; Nakamura, T.; Kawabata, Y. Techo. Jpn 1989, 22, 8; Vandevyver, M. Thin Solid Films 1992, 210-211, 240; Pearson, C.; Dhindsa, A. S.; Petty, M. C.; Bryce, M. ibid 1992, 210-211, 257 and references therein.
1164
R.P. Parg et al. / Synthetic Metals 70 (1995) 1163-1164
J, LiOH,dloxane,H20 S ~ s ii, H2N(CH2)3NHCPh3- ,-, y_ iii. 5%CF3CO2H,CH2CI2rtS'r ~5 •
refluxLiDMF., Br' ~ p . . ~ i O 2 M e Cl0H21 3 R, R = CH2CH2 2
R =
4
"
"
+
~r -H
6 R = CtoH21 7 R, R= CH2CH2
R = CloH21
5 FI,FI= CH2CH2
~ S~CONH(CH2)3NH3*s,,.. ~ , -~S ~ 7 b- ~H
~CONH(CH2)3NH3CF3C02"
a
S/'•S
CF3C02" DCC,HOBT, DIPEA,DMAP
H
8
CONH(CH2)3NHOC H 9
H2~CloS~ ~ ~
CONH(CH2)3NH3 ÷ CF3C02"
H21C1°S/~ 6 H H21C,OS~l~ . . ~ = S ~ C02H
H21Clo~SCloH21 H21CIo~SCloH21
DCC,HOBT. DIPEA,DMAP
H2,C,oS.,,.JLS/~-~'~L,. H
H
10
H21C1oS~1~ ~ . .
CONH(CHz)aNH3" CFaC02"
H21CloS'~ H 6 H21Clo~~s~,SCH2CO2H H21C|oS~
~
7 H21C,o S ~ ~ , . ~ . .
H2|C,o S ~ S / ~ ' = ~
SCH2CO2H
H2,CIo~SC,oH,,
H2,Cto~SC,oH2,
H/L~-~CONH(CH2)aNHOCCH2S/t'~SCH2CONH(CH2)3NHOC/~'=~H 13
CONH(CH2)3NH3*CFaC02 H
CONH(CH2)3NHOC H 11 27% H21C,oS~SC, oH2,
DCC,HOBT, DIPEA,DMAP
-- ~SCH2CO2H 12
~)~S~
21%
DCC.HOBT, DIPEA,DMAP
SCH2CO2H
~S
E "S
9%
H21Clo%~_.(SCloH21
S~ "S
~S
,~S
H~cONH(CH2)'NHOCCH2S~SCH2CONH(CH2)3NHOc-- H
12 14
13%
SCHEME 1
2 Williams, J. M.;Schultz, A. J.; Geiser, U.; Carlson, K. D.; Kini, A. M.; Wang, H. H.; Kwok, W. K.; Whangbo, M. H.; Schirber, J. E.; Science 1991, 252, 1502; Bryce, M. R. Chem. Soc. Rev. 1991, 20, 355.
3. Parg, R. P.; Kilburn, J. D.; Petty, M. C.; Pearson, C.; Ryan, T. G. Synthesis, 1994, 613. 4. Using a modification of the procedure reported by Duguay, G.; Gorgues, A. Synthetic Metals, 1993, 55-57, 2113.