T. Yamamoto et al. / Tetrahedron Letters 45 (2004) 7943–7946
Table 2. Redox potentials [V] of 1-syn, 1-anti, and thianthrene
7945
1-syn
1-anti
Thianthrene
Epa
Epc
E1/2
0.66
0.55
0.61
0.65
0.55
0.60
0.92
0.81
0.86
chemical oxidation correspond to the generation of sta-
ble radical cations.
In summary, we have succeeded in the synthesis, struc-
tural characterization, and examination of redox prop-
erties of 1,4-dithiins fused to two benzo[b]thiophenes,
1-syn and 1-anti. The molecules showed interesting
redox properties, reversible peaks, and low first oxida-
tion potential by CV measurement. Further studies on
the properties of 1-syn and 1-anti are in progress in
our laboratory.
Figure 5. Cyclic voltammograms of 1-syn and 1-anti.
Table 1. Epa, Epc values [V] of 1-syn and 1-anti
1-syn
1-anti
E1pa
E1pc
E2pa
E2pc
E3pa
E3pc
E4pa
E4pc
0.66
0.56
1.12
—
0.65
0.56
1.12
—
Acknowledgements
This work was supported by a Grant-in-Aid for Scien-
tific Research on Priority Areas (No. 16033205, ÔReac-
tion Control of Dynamic ComplexesÕ) and (No.
15550023) from Ministry of Education, Culture, Sports,
Science, and Technology, Japan.
1.29
—
1.27
—
1.58
—
1.53
—
References and notes
1. Reviews on OFETÕs: (a) Katz, H. E.; Bao, Z.; Gilat, S. L.
Acc. Chem. Res. 2001, 34, 359–369; (b) Katz, H. E.; Bao,
Z. J. Phys. Chem. B 2000, 104, 671–678; (c) Horowitz, G.
Adv. Mater. 1998, 10, 365–377; (d) Katz, H. E. J. Mater.
Chem. 1997, 7, 369–376.
range of 0–0.9V as shown in Figure 6 and low half-wave
potentials (Table 2; 0.61V for 1-syn and 0.60V for 1-
anti) compared with that of thianthrene (0.86V).
2. Dimitrakopoulos, C. D.; Malenfant, P. R. L. Adv. Mater.
2002, 14, 99–117.
The ESR spectra of chemically oxidized 1,4-dithiins
were measured for clarification of the generated oxida-
tion species in the first peaks. When 1-syn or 1-anti was
treated with 1equivalent of NOPF6 in THF at ꢀ78ꢁC,
the color of the reaction solution changed into deep
blue. After evaporation of the solvents the residues were
dissolved in CH3CN. The ESR spectra of the dithiins in
CH3CN showed broad singlet peaks (g = 2.0073 for 1-
syn, g = 2.0072 for 1-anti).13 These results suggest that
the first oxidation couplets of 1,4-dithiins in electro-
3. (a) Miao, Q.; Nguyen, T.; Someya, T.; Blanchet, G. B.;
Nuckolls, C. J. Am. Chem. Soc. 2003, 125, 10284–10287;
(b) Duong, H. M.; Bendikov, M.; Steiger, D.; Zhang, Q.;
Sonmez, G.; Yamada, J.; Wudl, F. Org. Lett. 2003, 5,
4433–4436; (c) Anthony, J. E.; Brooks, J. S.; Eaton, D. L.;
Parkins, S. R. J. Am. Chem. Soc. 2001, 123, 9482–9483.
4. (a) Wex, B.; Kaafarani, B. R.; Neckers, D. C. J. Org.
Chem. 2004, 69, 2197–2199; (b) Zhang, X.; Matzger, A. J.
J. Org. Chem. 2003, 68, 9813–9815.
5. Selected data for 1-syn: colorless crystals; mp 195.0–
196.0ꢁC; 1H NMR (400MHz, CDCl3) d 7.34 (t, 2H,
J = 7.8Hz, ArH), 7.41 (t, 2H, J = 7.8Hz, ArH), 7.71 (d,
2H, J = 7.8Hz, ArH), 7.76 (d, 2H, J = 7.8Hz, ArH); 13C
NMR (101MHz, CDCl3) d 120.9, 122.5, 125.0, 125.1,
126.4, 129.9, 136.5, 141.0; IR (KBr) m 1423, 1314, 1250,
744, 720cmꢀ1; MS (70eV) m/z 328 (M+); Anal. Calcd for
C16H8S4: C, 58.50; H, 2.45. Found: C, 58.18; H, 2.78.
6. Ashby, J.; Ayad, M.; Meth-Cohn, O. J. Chem. Soc.,
Perkin Trans. 1 1973, 1104–1107.
7. Dickinson, R. P.; Iddon, B. J. Chem. Soc. (C) 1968, 2733.
8. Selected data for 1-anti: colorless crystals; mp 207.0–
208.3ꢁC; 1H NMR (400MHz, CDCl3) d 7.34 (t, 2H,
J = 7.4Hz, ArH), 7.41 (t, 2H, J = 7.4Hz, ArH), 7.69 (d,
2H, J = 7.9Hz, ArH), 7.73 (d, 2H, J = 8.0Hz, ArH); 13C
NMR (101MHz, CDCl3) d 120.6, 122.5, 124.9, 125.0,
125.7, 131.3,136.3, 140.9; IR (KBr) m 1478, 1454, 1419,
1251, 1018, 910, 741, 718cmꢀ1; MS (70eV) m/z 328 (M+);
Anal. Calcd for C16H8S4: C, 58.50; H, 2.45. Found: C,
58.48; H, 2.57.
Figure 6. Cyclic voltammograms of 1-syn, 1-anti and thianthrene.