Conformational analysis of 3,3′-, 3,4′- and 4,4′-dimethoxy-2,2′-bithiophenes as models for related polymers

Abstract

An analysis of ¹³C chemical shifts of quaternary carbons of 3,3′-, 3,4′- and 4,4′-dimethoxy-2,2′-bithiophenes indicates they can be a useful tool for the identification of the inter-ring junction type. UV spectra and theoretical calculations are used to perform a conformational analysis of the compounds. The results show that the compounds prefer a non-planar conformation in non-condensated phases. The reasons for this non-planarity of the dimers and the effect on related polymers are discussed.

References

1. (a) A. Chang, R. L. Blankespoor and L. L. Miller, J. Electroanal. Chem., 1987, 236, 239; (b) A. Chang and L. L. Miller, Synth. Met., 1987, 22, 71; (c) S. Tanaka, M. Sato and K. Kaeriyama, Synth. Met., 1988, 25, 277; (d) K. Kaeriyama, S. Tanaka, M. Sato and K. Hamada, Synth. Met., 1989, 28, C611; (e) T. Yamamoto, A. Kashiwazaki and K. Kato, Makromol. Chem., 1989, 190, 1649; (f) M. Feldhues, G. Kämpf, H. Litterer, T. Mecklenburg and P. Wegener, Synth. Met., 1989, 28, C487; (g) L. H. Shi, F. Garnier and J. Roncali, Synth. Met., 1991, 41–43, 547; (h) M. Dietrich and J. Heinze, Synth. Met., 1991, 41–43, 503; (i) J. Daoust and M. Leclerc, Macromol., 1991, 24, 455; (j) J. Roncali, Chem. Rev., 1992, 92, 711; (k) P. Tschuncky and J. Heinze, Synth. Met., 1993, 55–57, 1603; (l) G. Zotti, M. C. Gallazzi, G. Zerbi and S. V. Meille, Synth. Met., 1995, 73, 217.
2. (a) J. L. Bredas, G. B. Street, B. Themans and J. M. André, J. Chem. Phys., 1985, 83, 1323; (b) M. Leclerc and R. E. Proud'homme, Polym. Bull., 1987, 18, 159; (c) R. M. Souto Maior, K. Hinkelmann, H. Eckert and F. Wudl, Macromol., 1990, 23, 1268.
3. (a) G. Barbarella, A. Bongini and M. Zambianchi, Macromol., 1994, 27, 3039; (b) G. Barbarella, M. Zambianchi, L. Antolini, U. Folli, F. Goldoni, D. Iarossi, L. Schenetti and A. Bongini, J. Chem. Soc., Perkin. Trans. 2, 1995, 1869.
4. (a) H. Satonaka, Bull. Chem. Soc. Jpn., 1983, 56, 2463; (b) K. Takahashi, T. Sone and K. Fujiada, J. Phys. Chem., 1970, 74, 2765.
5. S. V. Meille, A. Farina, F. Bezziccheri and M. C. Gallazzi, Adv. Mater., 1994, 6, 848.
6. (a) G. Barbarella, A. Bongini and M. Zambianchi, Adv. Mater., 1991, 3, 494; (b) C. Arbizzani, G. Barbarella, A. Bongini, M. Mastragostino and M. Zambianchi, Synth. Met., 1992, 52, 329.
7. (a) E. F. Paulus, R. Dammel, G. Kämpf, P. Wegener, K. Siam, K. Wolinski and L. Schäfer, Acta Crystallogr., Sect. B, 1988, 44, 509; (b) E. F. Paulus, K. Siam, K. Wolinski and L. Schäfer, J. Mol. Struct., 1989, 196, 171.
8. S. Samdal, E. J. Samuelsen and H. V. Volden, Synth. Met., 1993, 59, 259.
9. (a) G. Barbarella, M. Zambianchi, G. Bongini and L. Antolini, Adv. Mater., 1992, 4, 282; (b) 1993, 5, 834.
10. N. L. Allinger and Y. H. Yuh, MM2(91), Quantum Chemistry Program Exchange, Indiana University, Bloomington, IN 47405, USA.
11. M. Rajzmann and P. François, QCMP029, Quantum Chemistry Program Exchange, Indiana University, Bloomington, IN 47405, USA.
12. J. J. P. Stewart, MOPAC 6.0, Quantum Chemistry Program Exchange, Indiana University, Bloomington, IN 47405, USA.
13. L. L. Miller and Y. Yu, J. Org. Chem., 1995, 60, 6813.
14. P. Wegener and M. Feldhuis, Chem. Abstr., 1992, 117, 233842a.
15. (a) J. K. Stille, Angew. Chem., Int. Ed. Engl., 1986, 25, 508; (b) V. Farina and C. Krishnan, J. Am. Chem. Soc., 1991, 113, 9585; (c) Z. Bao, W. K. Chan and Y. Yu, J. Am. Chem. Soc., 1995, 117, 12 426.